FLUORIDE ACTION NETWORK PESTICIDE PROJECT

Return to FAN's Pesticide Homepage

Return to Abstracts Page


1989 Fluoride Abstracts. Part 1.

Abstracts for the following years:
Part 1 - mainly biochemistry and physiology (brain, hormonal, G-proteins, etc.)
Part 2 ("b") - all other

2007

2007-b

2004

2004-b

2001

2001-b

1998

1998-b

1995

1995-b

1992

1992-b

1989

1989-b

1986

1986-b

1983

1982

1976 -
1977
1970 -
1971

2006

2006-b

2003

2003-b

2000

2000-b

1997

1997-b

1994

1994-b

1991

1991-b

1988

1988-b

1985

1985-b

1981

1980

1974 -
1975
1968 -
1969

2005

2005-b

2005-b continued

2002

2002-b

1999

1999-b

1996

1996-b

1993

1993-b

1990

1990 -b

1987

1987-b

1984

1984-b

1979

1978

1972 -
1973
Up to
1967

http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2636961&dopt=Abstract

Zhonghua Bing Li Xue Za Zhi 1989 Dec;18(4):290-2

[Experimental study of behavior and cerebral morphology of rat pups generated by fluorotic female rat]

[Article in Chinese]

Liu WX.

In order to study the effects of fluoride on the central nervous system, 33-42-day old rat pups generated by three groups of female Wistar rats, which were given distilled water containing 0, 30 and 60 ppm NaF respectively beforehand as drinking water for 85 days, were used for behavior test and cerebral morphological examination. The results of behavior test showed that the latent period of pain reaction and that of conditioned reflex in the 30 ppm F and 60 ppm F groups were longer than that in the control group (P less than 0.05 or P less than 0.01). morphological examination of the pup brains showed that the nerve cell density of the 60 ppm F group was higher than that of the control group (P less than 0.05). Electronmicroscopically, mild degeneration of organelles of the nerve cells was observed in those brains of the 60 ppm F group.

PMID: 2636961 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2626692&dopt=Abstract

Shikwa Gakuho 1989 Mar;89(3):607-26

[The rabbit thermo-regulatory system. Effects of high dose of sodium fluoride]

[Article in Japanese]

Machida H.

The mechanism of sodium fluoride (NaF) induced hypothermia was investigated on relations between the monoamine synthesis and metabolism in the rabbit brain. Five male rabbits per a group, weighing about 2.5kg and having rectal temperatures of 38.4 to 39.3 degrees C, were used in this experiment. The rectal temperature measurements were made by means of an electric thermometer for 5 hours at intervals of 15 or 30 minutes. Through this experiment, animals were housed in a room kept at 22 to 23 degrees C. The following drugs were used in this experiment: NaF (40 mg/kg i.v.), barbital sodium (0.1 g/kg s.c.), hexamethonium bromide (C6, 10 mg/kg i.v.), ergotamine tartrate (30 mg/kg s.c.), phenoxybenzamine hydrochloride (15 mg/kg i.v.), propranolol hydrochloride (5 mg/kg s.c.), pindolol (0.3 mg/kg s.c.), atropine sulfate (30 mg/kg s.c.), 2, 4-dinitrophenol (DNP, 20 mg/kg i.v.), l-DOPA (20 mg/kg i.v.), 5-HTP (20 mg/kg i.v.) Results
1. Intravenous injection of 30 mg/kg of NaF induced a drop of 0.66 degrees C in rectal temperature.
2. Pretreatment with 0.1 mg/kg of barbital sodium or 10 mg/kg of C6 prominently inhibited the NaF-induced hypothermia.
3. The alpha-blockade caused by ergotamine tartrate and phenoxybenzamine or the beta blockade by propranolol hydrochloride and pindolol resulted in an approximate 50% inhibition of maximum drop in body temperature induced by NaF administration. Both alpha- and beta-blockades caused by ergotamine tartrate and propranolol or by phenoxybenzamine and pindolol, however, made a remarkable inhibition of the NaF effect. Cholinergic blockade brought on by atropine sulfate, on the other hand, had no effect against NaF-induced hypothermia.
4. Bilateral splanchnicotomy completely inhibited drops in rectal temperature.
5. Intravenous injection of NaF 40 mg/kg failed to counteract the rise of rectal temperature caused by DNP 20 mg/kg.
6. Pretreatment with l-DOPA made a prominent inhibition of NaF-induced hypothermia. The inhibiting effects of 5-HTP, however, were slight.
7. Administration of NaF made a significant decrease in norepinephrine levels in the rabbit hypothalamus, but had no effect on 5-HT levels.

PMID: 2626692 [PubMed - indexed for MEDLINE]


No Abstract

J Biol Sci Res 1989; 20:19-30

Araibi AA, Yousif WH, Al-Dewachi OS.

Effect of high fluoride on the reproductive performance of the male rat.

(Cited in: Toxicological profile for fluorine, hydrogen fluoride, and fluorides. Draft for public comment. Agency for Toxic Substances and Disease Registry. Atlanta, GA. 2001.
Cited in: Interaction Profile for Cyanide, fluoride, nitrate and uranium. Draft for public comment. Agency for Toxic Substances and Disease Registry. Atlanta, GA. 2002.)


Fluoride 1989; 22(1):78-85

Fluoride induced biochemical changes in reproductive organs of male mice

NJ Chinoy * and E Sequeira

* Department of Zoology, University School of Science, Gujarat University, Ahmedabad, India

Summary: Adult male albino mice were given 10 mg and 20 mg/kg body weight of NaF for 30 days. NaF caused a decrease in body weight, but no change in organ weight, except for the prostate gland and seminal vesicles. No significant change in testis cholesterol and serum testosterone levels occurred. However, in the testis succinic dehydrogenase levels decreased, in the epididmides sialic acid and ATPase levels decreased; in the vas deferens glycogen levels increased, seminal vesicles fructose levels increased in the prostate glands acid phosphatase and total protein levels increased. After withdrawal of treatment for a period of two months the levels of these substances returned to normal.


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2641145&dopt=Abstract

Patol Pol 1989;40(3):267-72

[Morphologic evaluation of the effect of long-term administration of ammonium fluoride on the seminiferous epithelium and epididymis in the rat]

[Article in Polish]

Rozewicka L, Put A, Dominiak B, Juzyszyn Z.

Male rats were subjected to 9-month-long exposure to ammonium fluoride. The performed evaluation covered the seminiferous epithelium and epididymis. The greatest changes in animals used in the experiment were observed in epididymis. A small number of spermatozoa were seen in the lumen of ductus epididymis, while in the epithelial cells there were increased phagocytic processes, providing a proof that injured reproductive cells were eliminated from the genital tract.

PMID: 2641145 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2520529&dopt=Abstract

Reprod Toxicol 1989;3(4):261-7

Effects of fluoride on the histoarchitecture of reproductive organs of the male mouse.

Chinoy NJ, Sequeira E.

Department of Zoology, University School of Sciences, Gujarat University, Ahmedabad, India.

The effects of sodium fluoride (NaF) ingestion in two doses (10 and 20 mg/kg body weight) for 30 days on histology and histocytometry of reproductive organs of the adult male mouse were investigated. In order to study reversibility, treatment was withdrawn for one and two months. The testes, epididymides, vas deferens, prostate, and seminal vesicle were utilized for the study by standard hematoxylin-eosin staining and an ocular eye piece and micrometer scale. NaF treatment caused severe disorganization and denudation of germinal epithelial cells of seminiferous tubules with absence of sperm in the lumina. The Leydig cell and nucleus diameters were not affected. The caput epididymis showed fewer changes than the cauda. However, epithelial cell nuclear pyknosis and absence of luminal sperm were observed. A reduction in epithelial cell height, nuclear pyknosis, denudation of cells, and absence of sperm occurred in the cauda epididymis. The vas deferens epithelium showed nuclear pyknosis, clumped stereocilia, and cell debris but no sperm in the lumen and an increase in the lamina propria. The prostate and seminal vesicles were not affected by treatment. Withdrawal of treatment caused marked recovery in the histoarchitecture of these organs. The effects of NaF treatment are therefore transient and reversible.

PMID: 2520529 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2612943&dopt=Abstract

Gig Tr Prof Zabol 1989;(9):19-22

[Chronic effects of fluorides on the pituitary-thyroid system in industrial workers]

[Article in Russian]

Tokar' VI, Voroshnin VV, Sherbakov SV.

Radioimmunologic study of thyrotropin and thyroid hormones in the blood of those engaged in fluorine production showed moderate functional changes of the hypophysis-thyroid gland system, not accompanied by clinical manifestations of hypo- or hyperthyreosis and caused by disorders of the regulatory chain and fluorine impact on thyroid hormones' metabolism at the level of target cells. Elevation of calcitonin concentration in workers' blood indicated stimulation of thyroid gland parafollicular cells. Phase states in the hypophysis-thyroid gland system were detected along with the dependence of some hormones' concentration on the duration of workers' contact with fluorine compounds and the stage of fluorosis.

PMID: 2612943 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2731668&dopt=Abstract

Fundam Appl Toxicol 1989 Apr;12(3):540-57

Inhalation toxicity of sulfuryl fluoride in rats and rabbits.

Eisenbrandt DL, Nitschke KD.

Mammalian and Environmental Toxicology Research Laboratory, Dow Chemical Company 48674.

The inhalation toxicity of the structural fumigant sulfuryl fluoride (SO2F2) was evaluated in rats and rabbits. Exposures for a preliminary 2-week study were 6 hr/day, 5 days/week, to 0, 100, 300, or 600 ppm SO2F2. Nine of ten rats at 600 ppm died or were moribund between the second and sixth exposures. Extensive kidney lesions were present in all rats exposed to 600 ppm, whereas only minimal renal changes were noted in rats at 300 ppm. Upper and lower respiratory tissues were inflamed in the single rat that survived the 2-week exposure to 600 ppm. Rabbits exposed to 600 ppm SO2F2 were hyperactive and one animal had a convulsion. Exposure to 300 or 600 ppm for 2 weeks resulted in vacuolation and/or malacia in the cerebrum of all rabbits and most of these rabbits also had moderate inflammation of nasal tissues; a few rabbits at 600 ppm had inflammation of the trachea or bronchi. A subsequent 13-week study evaluated rats and rabbits exposed to 0, 30, 100, or 300 ppm SO2F2 (337 ppm TWA for rabbits). Rabbits initially were exposed to a high concentration of 600 ppm; however, convulsions were noted in two animals after nine exposures and the concentration subsequently was reduced to 300 ppm. Vacuolation and/or malacia were observed in the cerebrum of all rabbits at the highest concentration; one rabbit exposed to 100 ppm also had cerebral vacuolation. Rabbits at the highest concentration, as well as one rabbit exposed to 100 ppm, had inflammation of the nasal tissues. Rats exposed to 300 ppm SO2F2 for 13 weeks had mottled incisor teeth, minimal renal effects, pulmonary histiocytosis, inflammation of nasal tissues, and cerebral vacuolation. Also, rats exposed to 100 ppm SO2F2 for 13 weeks had mottled teeth. Fluoride toxicity was suggested by mottled teeth in rats as well as elevation of serum fluoride levels in rats and rabbits exposed to SO2F2 for 13 weeks. Although repeated exposure of rats and rabbits to 100-600 ppm SO2F2 resulted in toxicity of the kidneys (rats only), brain, and respiratory system, no effects were detected in animals exposed to 30 ppm for 13 weeks.

PMID: 2731668 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2725829&dopt=Abstract

Neurochem Res 1989 Mar;14(3):285-91

Alterations in the distribution of cholinesterase molecular forms in maternal and fetal brain following diisopropyl fluorophosphate treatment of pregnant rats.

Meneguz A, Bisso GM, Michalek H.

Laboratory of Pharmacology, Istituto Superiore di Sanita, Roma, Italy.

Previous work in this laboratory showed that during intoxication of rats with diisopropyl fluorophosphate at day 20 of pregnancy the recovery of ChE activity was faster in fetal than in maternal brain. In the present study the differences between recovery rats in dam and fetus brain were evaluated in terms of molecular forms and spontaneous reactivation. Using ultracentrifugation on sucrose gradient two molecular forms of ChE, namely 10S (tetrameric globular G4 form) and 4S (monomeric G1 form) were detected both in maternal and fetal brain of untreated rats. The ratios 10S/4S were about 5.0 and 0.75 for dams and 20-day fetuses, respectively. DFP administration (1.1 mg/kg sc) inducing at 90 min an about 80% inhibition of ChE in maternal brain caused a shift in its 10S/4S ratio to 1.63, and to 0.53 in fetal brain (in which overall inhibition was about 70%). This means that 10S forms were preferentially inhibited by DFP both in maternal and fetal brain. After 24 and 48 hr there was a negligible recovery of overall ChE in maternal brain with no shift in the ratio. On the other hand, complete recovery of ChE in fetal brain within 48 hr was accompanied by almost total normalization of the 10S/4S ratio. Rapid recovery of fetal ChE appeared not to depend on hydrolysis of DFP-inhibited ChE. In fact, maternal and fetal DFP-inhibited enzyme preparations following the addition of oximes (pralidoxime or obidoxime) in vitro showed similar rates of reactivation. The overall data indicate considerable differences in recovery rate of molecular forms between dams and fetuses, but not in reactivation by dephosphorylation.

PMID: 2725829 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2544797&dopt=Abstract

Mol Biol (Mosk) 1989 Jan-Feb;23(1):306-14

[Selective inhibition of 3'-5'-exonuclease activity of DNA-polymerase I from Escherichia coli by a fluoride ion]

[Article in Russian]

Mikhailov VS, Ataeva DO, Marlyev KA, Atrazhev AM.

The effect of NaF on the enzymatic activities of the large fragment of E. coli DNA polymerase I (Klenow enzyme-KE) with different DNA-substrates was studied. It was shown that fluoride ion at concentrations of 5-10 mM efficiently inhibits the 3'----5' exonuclease activity of KE but does not affect the polymerase activity of the enzyme. Selective inhibition of the 3'----5' exonuclease activity of KE is Mg-dependent and is observed with double- or single-stranded DNAs. In reaction with the 14-mer oligonucleotide annealed with single-stranded phage M13 DNA the enzyme was found not only to perform the exonucleolytic hydrolysis of the primers but to catalyse also a limited elongation of some primers, adding a few nucleotide residues in the absence of exogenous dNTP. The primer elongation is inhibited by inorganic pyrophosphatase and is stimulated by micromolar concentrations of exogenous pyrophosphate thus suggesting a possible role of PPi contamination in dNTP generation via pyrophosphorolysis. Traces of precursors in DNA preparations obtained by generally employed methods may serve as another source of nucleotides for the primer elongation.

PMID: 2544797 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2500593&dopt=Abstract

Mutat Res 1989 Jun;223(2):191-203

Erratum in: Mutat Res 1989 Aug;223(4):417

Sodium fluoride-induced chromosome aberrations in different stages of the cell cycle: a proposed mechanism.

Aardema MJ, Gibson DP, LeBoeuf RA.

Procter and Gamble Company, Miami Valley Laboratories, Cincinnati, OH 45239.

In an attempt to clarify the controversy about sodium fluoride (NaF) clastogenicity, the induction of chromosome aberrations in Chinese hamster ovary cells (CHO) by NaF was investigated. Following a protocol used for screening chemicals for clastogenic activity, significant increases of aberrant cells were observed when cells were exposed to NaF for 4 h and harvested 8 h later. Cell-cycle kinetic studies demonstrated most cells were exposed in G2 of the cell cycle. Smaller increases in aberrant cells were observed when cells were harvested 20 h later (most cells were exposed in G1/S). The sensitivity of G2 cells to NaF was investigated further, along with the induction of aberrations at low doses. The results indicated that G2 cells are sensitive to NaF and the percent of aberrant cells increased with dose and length of exposure. With a 3-h exposure until harvest, no statistically significant increase in aberrant cells was observed at doses below 10 micrograms/ml NaF. These data are consistent with a threshold for NaF-induced clastogenicity around 10 micrograms/ml, as has been proposed previously (Scott and Roberts, 1987). It thus may be predicted that clastogenic effects would not occur in humans exposed to the levels of fluoride that are present in drinking water or dentifrices. An understanding of the mechanism of NaF-induced clastogenicity would help to clarify this point. It has previously been reported that NaF inhibits DNA synthesis/repair. The types of aberrations, mostly deletions and gaps, the induction of endoreduplicated cells, the cell-cycle delay and the sensitivity of G2 cells to NaF observed are similar to that reported in the literature for DNA synthesis/repair inhibitors like aphidicolin (APC). Similarities in the induction of aberrations by NaF and APC were confirmed in experiments with G2 cells. Based on these results and those previously reported for NaF and APC, it is proposed that NaF-induced aberrations may occur by an indirect mechanism involving the inhibition of DNA synthesis/repair.

PMID: 2500593 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2521626&dopt=Abstract

J Biol Chem 1989 Feb 5;264(4):2302-6

RecA protein-promoted cleavage of LexA repressor in the presence of ADP and structural analogues of inorganic phosphate, the fluoride complexes of aluminum and beryllium.

Moreau PL, Carlier MF.

Laboratory of Enzymology, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.

Complexes formed from A13+ or Be2+ and fluoride inhibit the single-stranded DNA-dependent ATPase activity of RecA protein. In contrast, poly(dT)-RecA-ADP complexes, which are inactive for cleavage of LexA protein, become fully active in the presence of AlF4- or BeF3- ions. These data suggest that fluoride complexes of aluminum and beryllium (called herein X) convert RecA-ADP complexes, which bind weakly to single-stranded DNA, into RecA-ADP-X complexes, which bind tightly to single-stranded DNA, the ADP-X moiety behaving as a nonhydrolyzable analogue of ATP. We propose that AlF4- and BeF3- ions act as analogues of inorganic phosphate by binding to the site of the gamma-phosphate of ATP on RecA-ADP complexes, hence mimicking the single-stranded DNA-RecA-ADP-Pi transition state. We conclude that the elementary reaction that switches RecA protein from a high affinity single-stranded DNA binding state to a low affinity single-stranded DNA binding state is not ATP hydrolysis per se but Pi release.

PMID: 2521626 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2500363&dopt=Abstract

FEBS Lett 1989 Jun 5;249(2):189-94

Receptor and effector interactions of Gs. Functional studies with antibodies to the alpha s carboxyl-terminal decapeptide.

Simonds WF, Goldsmith PK, Woodard CJ, Unson CG, Spiegel AM.

Molecular Pathophysiology Branch, National Institute of Diabetes, Digestive and Kidney Diseases, Bethesda, MD 20892.

Antibodies generated to a synthetic decapeptide, RMHLRQYELL, representing the carboxyl-terminus of Gs-alpha have been characterized in immunoblots and functional studies. This antibody, designated RM, reacts exclusively with a doublet of proteins of 52 and 45 kDa in immunoblots of bovine brain and wild-type S49 murine lymphoma cell membranes. No such reactivity is seen in membranes from cyc- S49 cells, which lack Gs. RM blocks receptor-mediated activation of Gs and adenylyl cyclase in membranes from wild-type S49 cells. RM could also immunoprecipitate adenylyl cyclase activity in detergent extracts from GTP[gamma]S- or fluoride-preactivated bovine brain membranes; thus binding of alpha s to effector and carboxyl-terminal antibody was mutually compatible. Such experiments provide an approach for the elucidation of functionally relevant interactions of G-proteins with receptors and effectors in the membrane.

PMID: 2500363 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2503507&dopt=Abstract

J Biol Chem 1989 Aug 15;264(23):13917-22

Modification of AlF-4- and receptor-stimulated phospholipase C activity by G-protein beta gamma subunits.

Boyer JL, Waldo GL, Evans T, Northup JK, Downes CP, Harden TK.

Department of Pharmacology, School of Medicine, University of North Carolina, Chapel Hill 27599.

Turkey erythrocyte membranes possess a phospholipase C that is markedly activated by P2Y-purinergic receptor agonists and guanine nucleotides. Reconstitution of [3H]inositol-labeled turkey erythrocyte membranes with guanine nucleotide regulatory protein (G-protein) beta gamma subunits resulted in inhibition of both AlF-4-stimulated adenylate cyclase and AlF-4-stimulated phospholipase C activities. The apparent potency (K0.5 approximately 1 microgram or 20 pmol of beta gamma/mg of membrane protein) of beta gamma subunits for inhibition of each enzyme activity was similar and occurred with beta gamma purified by different methodologies from turkey erythrocyte, bovine brain, or human placenta membranes. In contrast to the effect on AlF-4-stimulated activity, the stimulatory effect on phospholipase C of the P2Y-purinergic receptor agonist 2-methylthioadenosine 5'-triphosphate in the presence of guanine nucleotides was potentiated by 50-100% in a concentration-dependent manner by reconstitution of beta gamma subunits. beta gamma subunits did not affect the K0.5 value of 2-methylthioadenosine 5'-triphosphate for the stimulation of phospholipase C activity. These results indicate that beta gamma subunits influence phospholipase C activity in a concentration range similar to that necessary for regulation of adenylate cyclase activity and suggest the involvement of a G-protein possessing an alpha beta gamma heterotrimeric structure in coupling hormone receptors to phospholipase C.

PMID: 2503507 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2553586&dopt=Abstract

Immunology 1989 Oct;68(2):240-6

Effect of sodium fluoride on the generation of lipoxygenase products from human polymorphonuclear granulocytes, mononuclear cells and platelets--indication for the involvement of G proteins.

Brom C, Koller M, Brom J, Konig W.


Lehrstuhl fur Medizinische Mikrobiologie und Immunologie, Arbeitsgruppe Infektabwehrmechanismen, Ruhr-Universitat Bochum, FRG.

Incubation of human polymorphonuclear granulocytes, monocytes and platelets with sodium fluoride (NaF) results in a time- and dose-dependent generation of leukotrienes and 12-HETE, respectively. This release was not influenced by pretreatment with pertussis toxin or cholera toxin. The mediators are detectable after a lag phase of about 5-10 min. Inactivation of LTB4 by the neutrophils via omega-oxidation into 20-hydroxy-LTB4 and 20-carboxy-LTB4 is inhibited by NaF. In combination with other cell stimuli, NaF showed modulatory effects, such as an enhanced formation of the leukotrienes when FMLP, opsonized zymosan, PMA, and arachidonic acid were applied as stimuli. Prestimulation of cells with NaF causes an increased [3H]guanylylimidodiphosphate binding to isolated membrane preparations, indicating an enhanced exchange rate for GDP to GTP. Our data demonstrate that a direct activation of GTP-binding proteins results in the generation of the inflammatory mediators and provides evidence for the involvement of the signal-transduction pathway.

PMID: 2553586 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2505898&dopt=Abstract

Calcif Tissue Int 1989 Aug;45(2):71-3

Suggestion of a deficient osteoblastic function in diabetes mellitus: the possible cause of osteopenia in diabetics.

Rico H, Hernandez ER, Cabranes JA, Gomez-Castresana F.

Department of Internal Medicine, Medical School, Universidad de Alcala de Henares, Madrid, Spain.

The mechanism underlying diabetic osteopenia is still unclear and may involve osteoblastic activity and/or the deficit of insulin's anabolic action. Bone gla protein (BGP) is synthesized by the osteoblast and its synthesis increases with 1,25(OH)2D3 and fluoride. Because 1,25(OH)2D3 also stimulates insulin secretion, sodium fluoride administration can be used to investigate deficient osteoblastic activity in diabetics, as reflected by BGP levels. BGP was determined before and after administering sodium fluoride at a dosage of 50 mg/day/15 days to three groups: 14 patients with insulin-dependent diabetes, 16 diabetics on oral antidiabetic treatment, and 25 controls, all of similar age, sex, and characteristics. Basal BGP values (mean +/- SD) were low in diabetics on insulin treatment (4.3 +/- 1.1 ng/ml) and in diabetics on oral antidiabetics (5.8 +/- 1.2 ng/ml) as compared with controls (6.5 +/- 0.7 ng/ml) (P less than 0.001 and less than 0.05, respectively). After giving fluoride, BGP values did not change in the two diabetic groups but did vary in controls (8.1 +/- 0.6 ng/ml, P less than 0.001). These results suggest that deficient osteoblast function could be responsible for osteopenia in diabetics.

PMID: 2505898 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2545777&dopt=Abstract

J Immunol 1989 Aug 1;143(3):780-6

Stimulation of PIP2 hydrolysis by aluminum fluoride in resting T cell subsets of normal and autoimmune-prone lpr mice.

Coggeshall KM, Altman A.

Scripps Clinic and Research Foundation, Department of Immunology, La Jolla, CA 92037.

T cells of autoimmune-prone mice homozygous for the lpr mutation respond poorly to mitogens in terms of proliferation and of IL-2 production. In a previous study, we have correlated this deficient activation with the inability of mitogens to stimulate hydrolysis of phosphatidylinositol 4,5-bisphosphate in lpr T cells, although these cells bind mitogen and express the TCR/CD3 complex. In order to determine whether activation-deficient lpr T cells contain functional GTP-binding (G) protein(s) and phospholipase C, we examined the effects of the G protein activating agent sodium fluoride plus Al+3 (AlF-4). AlF-4 stimulated phosphatidylinositol turnover, a response characteristic of TCR/CD3 occupancy, in mature L3T4+ and Ly2+ T cells. Second, and more important, AlF-4 stimulated the same biochemical events in L3T4-, Ly2- (double-negative) T cells from the normal thymus or from the enlarged lymph nodes of autoimmune-prone mice homozygous for the lpr mutation. However, these double-negative T cells were unresponsive to receptor-active ligands such as T cell mitogens or anti-CD3-epsilon mAb, despite their ability to bind these ligands. These findings suggest that activation-deficient double negative T cells express the receptors, G protein(s) and effector enzymes necessary for second messenger formation and further suggest that the failure of these cells to generate the relevant second messengers in response to mitogens or anti-CD3-epsilon antibody may be due to inefficient coupling of the TCR/CD3 complex to G proteins.

PMID: 2545777 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2777755&dopt=Abstract

J Biochem (Tokyo) 1989 Jul;106(1):8-10

Aluminum enhances the stimulatory effect of NaF on prostaglandin E2 synthesis in a clonal osteoblast-like cell line, MOB 3-4, in vitro.

Kawase T, Ishikawa I, Orikasa M, Suzuki A.

Department of Pharmacology, Niigata University School of Dentistry.

The effect of NaF on prostaglandin E2 (PGE2) synthesis in a clonal osteoblast-like cell line, MOB 3-4, was examined in the presence of Al3+. The MOB 3-4 cell line, which was derived from neonatal mouse calvaria, displays many osteoblastic characteristics, including the biosynthesis of PGE2. In the absence of Al3+, 1 mM NaF increased PGE2 synthesis (per well) to about 340% of the control level, whereas NaF at lower concentrations (below 0.1 mM) did not show such a significant effect. In the presence of 10 microM Al3+, NaF concentrations ranging from 0.01 to 1 mM increased PGE2 synthesis in a dose-dependent manner, though 10 microM Al3+ had no effect by itself. Similar effects were observed on alkaline phosphatase (ALP) activity per well, but a stimulatory effect of NaF on protein synthesis was observed only in the presence of 10 microM Al3+. These data demonstrated that PGE2 synthesis per protein was increased by NaF alone, and this effect was markedly enhanced by the addition of AlCl3. ALP activity per protein was, however, significantly increased by NaF in the absence of AlCl3. Taken together with our previous finding that Al3+ enhances the NaF-induced Ca2+ mobilization in MOB 3-4 cells, these results suggest that F- combined with Al3+ (i.e., AlF4-) is a more potent stimulator of PGE2 synthesis in cells than F- alone, and that the AlF4- -enhanced PGE2 synthesis may be caused by an increase in cytosolic free Ca2+ concentration during activation of the G protein by AlF4-.

PMID: 2777755 [PubMed - indexed for MEDLINE]


From TOXNET

Teratology 1989 Sep;40(3):285

Does fluoride interfere with normal gestation of the rat?

Horvath C

Facultže de Mžedecine Saint-Antoine, Service de Biophysique, Paris, France

The effect of fluoride is not sufficiently investigated during pregnancy. Some authors have reported a differential inhibition of cardiac development of chicken in vitro. Decalcification and histological changes in the teeth of mouse fetuses and retarded ossification of the skeleton of rat fetuses were observed. The results are contradictory concerning human development and fluoridation. Thus the major uncertainty with the use of fluoride during gestation requires a systematical study. Four groups of female rats (Wistar, bred in our Institut) were treated. Two groups received a daily NaF dose of 15 mg/kg intraperitoneally, administered either on the 7-14th or 14-20th days of gestation. Two groups were treated with physiological saline (solvent) on the same days of gestation. A fifth group without any treatment served as control of our strain. No material toxicity was observed. At term, fetal mortality was not significantly different. Some external malformations were noted without significant differences among the experimental groups. Fetal skeletons were stained, first with Alcian Blue for cartilage, then, with Alizarin red S for bone. The preliminary results reveal a significant increase in skeletal retardation and skeletal malformations of sternebrae and thoracic vertebrae. Occurrence of 14th ribs was increased. Skeletal retardations and malformations were mainly observed in the group treated during the 14-20th day of gestation. Therefore the use of fluoride supplementation water or salt during the last trimester pregnancy should be investigated.


Fluoride 1989; 22(3):128-130

Blood serum alkaline phosphatase in rats following dexamethasone and fluoride supplementation

KC Kanwar * and S Dhar

Department of Biophysics, Panjab University, Chandigarh, India

Summary: Alkaline phosphatase activity in the blood serum of rats has been studied following heavy dexamethasone (a glucocorticoid) administration as well as after fluoride supplementation.

A significant increase in blood serum alkaline phosphatase activity has been recorded following fluoride supplementation which is considered indicative of increased osteoblastic stimulation as a result of fluroide intake. Dexamethasone, on the other hand, failed to alter significantly blood serum alkaline phosphatase activity.


Fluoride 1989; 22(4):165-168

Effect of fluoride on reproduction in mice

Pillai KS *, Mathai AT, Deshmukh

Jai Research Foundation, Of N.H. No. 8, Valvada, Taluka Umbergam, Dist. Valsad, Gujarat 396108, India

Summary: Mice were administered daily 17.3 and 5.2 mg F/b.w. (1/3rd and 1/10th LD50, respectively) orally from day 6 of mating until day 15 (10 days). Body weight and amount of food consumed were measured daily, until day 21, when the experiment was terminated. Fluoride-treated mice showed no sign of pregnancy; body weight and RBC counts declined. Hemoglobin declined significantly in mice given 5.2 mg F/kg b.w.


Fluoride 1989; 22(1):33-39

Effect of fluoride in excess on lipid constituents of respiratory organs in albino rabbits

Shashi *, Singh JP, Thapar SP

* Department of Zoology, Punjabi University, Patiala, India

Summary: Total lips and their various fractions namely, triglycerides, free fatty acids, cholesterol and phospholipids of respiratory organs (lungs and trachea) of rabbits were analyzed following subcutaneous injections of NaF for 100 days. The level of total lipids and neutral lipids decreased during fluoride intoxication. Triglycerides and free fatty acids showed overall decrease in fluoridated rabbit respiratory organs compared to controls. Cholesterol content of trachea was reduced in low fluoride groups and increased in high fluoride groups in both sexes. In lungs, the level of cholesterol fell in fluorotic groups, Phospholipids showed no significant change in the lung of males whereas in females the amount was significantly elevated. In female trachea, the concentration of phospholipids increased in the high fluroide group. In trachea of males the increase in concentration of phosopholipids in 10 and 20 mg F- groups was significant.


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2784677&dopt=Abstract

Biochem Biophys Res Commun 1989 Mar 31;159(3):1290-6

A novel calcium signalling response in the breast cancer cell line MDA-468.

Kremer S, Margolis B, Skorecki K.

Membrane Biology Group, University of Toronto, Canada.

In the human breast carcinoma cell line MDA-468 addition of epidermal growth factor (EGF) is growth inhibitory. Calcium signalling was investigated in this cell line using the calcium sensitive fluorescent probe Indo-1. Addition of EGF to MDA-468 cells resulted in a novel biphasic calcium response. In the first phase of the response EGF raised calcium to levels significantly above basal. This was followed by a prolonged fall in calcium to levels significantly lower than original basal levels. The G-protein activator aluminum fluoride (AlF), stimulated a rise in calcium which was not proceeded by a fall below basal levels. Conversely addition of PMA, an activator of protein kinase C (PKC), induced a fall in calcium from basal without a prior increase. Down regulation of PKC eliminated the response to PMA, however the biphasic nature of the EGF response was maintained. Pretreatment of the cells with pertussis toxin did not alter the response to EGF nor to AlF. We conclude that in the MDA-468 cell in which EGF is growth inhibitory:
1) EGF results in a biphasic calcium response which ultimately leads to reduction below baseline levels,
2) a rise in calcium itself is not sufficient to account for the subsequent fall below basal levels,
3) G-proteins may be involved in the initial phase of the EGF response,
4) activation of PKC can also reduce intracellular calcium, however the response to EGF is not dependent on this pathway.

PMID: 2784677 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2540850&dopt=Abstract

Biull Eksp Biol Med 1989 Mar;107(3):281-3

[Effect of fluorine on heart arrhythmias in rats]

[Article in Russian]

Karpova MN.

The antiarrhythmic activity of fluoride was studied in a model of CaCL2-induced heart arrhythmias in male albino rats. The prolonged intake of sodium fluoride with drinking water (2 mg/l for 1 month) significantly reduced the severity of arrhythmias that was evident as an increase in the latency and a decrease in the frequency and duration of arrhythmias. A less pronounced effect was noted when the concentration of sodium fluoride was increased to 5 mg/l. At larger concentrations (11 mg/l) the fluoride exerted a toxic effect and potentiated the arrhythmogenic action of CACL2. The antiarrhythmic action of fluoride in low concentrations may be associated with the blockade of an inward Ca current.

PMID: 2540850 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2536074&dopt=Abstract

J Neurochem 1989 Feb;52(2):498-506

Subacute and chronic in vivo lithium treatment inhibits agonist- and sodium fluoride-stimulated inositol phosphate production in rat cortex.

Godfrey PP, McClue SJ, White AM, Wood AJ, Grahame-Smith DG.

MRC Unit, Radcliffe Infirmary, Oxford, England.

We have investigated the effects of in vivo lithium treatment on cerebral inositol phospholipid metabolism. Twice-daily treatment of rats with LiCl (3 mEq/kg) for 3 or 16 days resulted in a 25-40% reduction in agonist-stimulated inositol phosphate production, compared with NaCl-treated controls, in cortical slices prelabelled with [3H]inositol. A small effect was also seen with 5-hydroxytryptamine (5-HT) 24 h after a single dose of LiCl (10 mEq/kg). Dose-response curves to carbachol and 5-HT showed that lithium treatment reduced the maximal agonist response without altering the EC50 value. This inhibition was not affected by the concentration of LiCl in the assay buffer. Stimulation of inositol phosphate formation by 10 mM NaF in membranes prepared from cortex of 3-day lithium-treated rats was also inhibited, by 35% compared with NaCl-treated controls. Lithium treatment did not alter the kinetic profile of inositol polyphosphate formation in cortical slices stimulated with carbachol. Muscarinic cholinergic and 5-HT2 bindings were unaltered by lithium, as was cortical phospholipase C activity and isoproterenol-stimulated cyclic AMP formation. [3H]Inositol labelling of phosphatidylinositol 4,5-bisphosphate was significantly enhanced by 3-day lithium treatment. The results, therefore, indicate that subacute or chronic in vivo lithium treatment reduces agonist-stimulated inositol phospholipid metabolism in cerebral cortex; this persistent inhibition appears to be at the level of G-protein-phospholipase C coupling.

PMID: 2536074 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2465376&dopt=Abstract

J Neurochem 1989 Mar;52(3):699-704

Effects of cyclic nucleotides and calcium/calmodulin on protein phosphorylation in the CNS of Hirudo medicinalis.

Garcia-Gil M, Berton F, Tongiorgi E, Brunelli M.

Department of Physiology and Biochemistry, University of Pisa, Italy.

Protein phosphorylation plays an important role in the regulation of neural functions. We have studied the phosphorylation of proteins in homogenates of segmental ganglia of the leech Hirudo medicinalis. We describe a number of proteins whose phosphorylation is dependent on calcium/calmodulin or cyclic nucleotides. Most of the proteins whose phosphorylation is increased in the presence of calcium seem to be substrates for cyclic nucleotide-dependent protein kinases. Only two of the phosphoproteins described appear to be specific substrates for calcium/calmodulin protein kinase(s), and at least six phosphoproteins appear to be specific substrates for cyclic nucleotide-dependent kinase(s). The leech nervous system, with large and identifiable neurons, provides a good tool for studies of neural functions, such as learning. The results are discussed in the context of the role of protein phosphorylation on learning processes.

PMID: 2465376 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2537330&dopt=Abstract

J Clin Endocrinol Metab 1989 Feb;68(2):379-85

Changes in adenylyl cyclase activity of the human and nonhuman primate corpus luteum during the menstrual cycle and pregnancy.

Rojas FJ, Moretti-Rojas IM, Balmaceda JP, Asch RH.

Department of Obstetrics and Gynecology, University of California-Irvine, Orange 92668.

Adenylyl cyclase (AC) activity in membrane particles of corpora lutea (CL) from humans and cynomolgus monkeys was examined at various stages of the menstrual cycle and pregnancy. AC activity was monitored by the conversion of [alpha-32P]ATP into [32P]cAMP under basal conditions and in the presence of several activators: NaF (10 mmol/L) plus forskolin (100 mumol/L); hCG (10 micrograms/mL); guanyl 5'-yl-imidodiphosphate [GMP-P(NH)P; 100 mumol/L]; and hCG (10 micrograms/ml) plus GMP-P(NH)P (100 mumol/L). The groups of human CL were midluteal (n = 10), late luteal (n = 4), following cycle (old CL; n = 5), and early pregnancy (6-11 weeks; n = 10). The groups of monkey CL were early luteal (n = 4), midluteal (n = 5), and pregnancy at term (n = 3). Luteal AC activity changed significantly during the menstrual cycle. In newly (less than 48 h after ovulation) formed CL, the enzyme was unresponsive to hCG, and total AC activity, as determined by NaF plus forskolin, averaged 86.5 +/- 28.9 (+/- SE) pmol cAMP/min.mg protein. As the CL developed, AC activity increased. Thus, in the midluteal phase, maximal hCG responsiveness in the presence of guanine nucleotide was 125 +/- 27 and 232 +/- 15 pmol/min.mg in human and monkey CL, respectively. No hCG responsiveness was detected in the late luteal phase or in the old CL. Maximal AC activity was also high in the midluteal phase (382 +/- 56 and 256 +/- 28 pmol/min.mg in human and monkey CL, respectively); the activity remained fairly high during the late luteal phase and then declined to less than 100 pmol/min.mg in the follicular phase of the next cycle. During early pregnancy, luteal AC was unresponsive to hCG stimulation, yet basal levels, maximal activity, and the characteristics of stimulation by nonhormonal activators were similar, if not identical, to those at the midluteal phase of the menstrual cycle. At term pregnancy, the enzyme remained unresponsive to hCG. However, basal activity and stimulation by NaF and forskolin were remarkably elevated, being between 2- and 7-fold higher than corresponding stimulations in the midluteal phase. We conclude that 1) AC activity in human luteal membranes is highly dependent on hormonal changes and functional state of the ovary, 2) the activity of luteal AC is similar in the CL of humans and cynomolgus monkeys, and 3) the AC system in the primate CL is functionally active during and at the end of pregnancy.(ABSTRACT TRUNCATED AT 400 WORDS)

PMID: 2537330 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2606338&dopt=Abstract

Gen Pharmacol 1989;20(5):705-10

Deleterious effect of sodium fluoride on gastrointestinal tract.

Fujii A, Tamura T.

Department of Pharmacology, Nihon University School of Dentistry, Chiba, Japan.

1. The effect of sodium fluoride (NaF) on gastrointestinal tracts of rats was investigated.
2. Blood flow rate in rat stomach mucosa was only 30% of the initial rate during 30-60 min after a single oral dose (300 mg/kg) of NaF.
3. The addition of NaF (final NaF concentration: 50 and 100 ppm) in vitro gave the reduction of 10 and 28%, respectively, of initial free calcium ion levels in rat blood.
4. These results indicate that oral ingestion of excess amount of NaF caused dilatation of blood vessel and greatly decreased blood flow rate to accumulate the circulating blood in the mucosa of gastrointestinal tract to cause redness.

PMID: 2606338 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2561948&dopt=Abstract

Cell Signal 1989;1(6):561-8

Biphasic effect of sodium fluoride and guanyl nucleotides on binding to prostaglandin E2 receptors in rat epididymal adipocyte membranes.

Cohen-Luria R, Sigler L, Rimon G.

Department of Clinical Pharmacology, Corob Research Center, Ben-Gurion University of the Negev, Beer Sheva, Israel.

Both NaCl and NaF promoted PGE2 binding to epididymal adipocyte membranes by apparent increase in the binding affinity. In order to distinguish between the effect of fluoride and the 'salt effect' of sodium on PGE2 binding, the effects of Mg2+ and guanyl nucleotides on PGE2 binding in the presence of NaCl or NaF were compared. Mg2+ decreased PGE2 binding; high NaF concentration abolished this inhibition, while increased NaCl concentrations did not affect the Mg2+ inhibition. In the presence of Mg2+ the effects of NaCl and NaF were additive. The enhancement of PGE2 binding by fluoride, unlike sodium, was dependent on the presence of Mg2+. Incubation of the membranes with GDP beta S, Gpp(NH)p, GTP or GTP gamma S increased PGE2 binding. Gradual increase in NaF concentrations in the presence of guanyl nucleotides resulted in stimulation of PGE2 binding at low NaF concentrations and inhibition of PGE2 binding at high NaF concentrations. No changes in the stimulatory action of NaCl on PGE2 binding were observed in the simultaneous presence of NaCl and guanyl nucleotides. A biphasic effect on PGE2 binding was observed with a wide concentration range of guanyl nucleotides. Treatment of the isolated membranes with cholera or pertussis toxins stimulated the adenylyl cyclase activity of the membranes, but failed to influence PGE2 binding. The implications of these findings are discussed.

PMID: 2561948 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2489303&dopt=Abstract

Shigaku 1989 Aug;77(2):436-47

[Dependence of lethality and incidence of chromosome aberrations induced by treatment of synchronized human diploid fibroblasts with sodium fluoride on different periods of the cell cycle]

[Article in Japanese]

Suzuki N, Tsutsui T.

The cytotoxic and clastogenic effects of sodium fluoride during various phases of cell cycle of human cultured diploid fibroblasts were examined. The cells in confluence were synchronized at G1/G0 phase by a period of growth in medium containing 1% serum (low serum medium). To obtain the cells in S phase and G2 phase, exponentially growing cells were cultured in low serum medium with a subsequent blockage of the cells at the G1/S boundary by hydroxyurea. Synchronized cells were treated with sodium fluoride for 3 hr during the G1 phase or G2 phase, and for each of three 3-hr periods during the S phase which lasted 9 hr. The cytotoxicity, as determined by a decrease in colony-forming ability, was dependent upon the phase of cell cycle during which treatment was administered. The highest lethality was observed for treatment in early to middle S phase, whereas scare lethality was observed in G1 phase. Inducibility of chromosome aberrations of the cells following treatment with sodium fluoride was also dependent upon the phase of cell cycle. Significant increase in the incidence of chromosome aberrations was observed only in cultures treated during early and/or middle S phases of the cell cycle. These results indicate that cytotoxicity and clastogenicity of sodium fluoride to cultured human diploid fibroblasts are cell phase dependent, and that the cells in early and middle S phases are more sensitive to these effects.

PMID: 2489303 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2552463&dopt=Abstract

Abstract not available

Prog Clin Biol Res 1989;301:309-14

Different pathways initiating arachidonic acid (AA) release/thromboxane (TxA2) formation in human platelets--studies with fluoride and phorbol ester.

Lenfers B, Kienast J, van de Loo J.

Medizinische Klinik und Poliklinik, Westfalische Wilhelms-Universitat, Munster, FRG.

PMID: 2552463 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2545286&dopt=Abstract

Biol Neonate 1989;55(3):171-9

Sensitivity of the renal adenylate cyclase receptor system to parathormone during the last third of pregnancy in the rat.

Gugi B, Mallet E.

Groupe de Recherche de Biologie du Developpement, UER Medecine-Pharmacie de Rouen, Saint-Etienne-du-Rouvray, France.

During the last third of pregnancy, the rat phospho-calcic metabolism is clearly modified. Sensitivity of the renal receptor to parathormone (PTH) was investigated over this period in the fetuses and their mothers. As early as day 16.5 of pregnancy, the fetal kidney is sensitive to bovine PTH (1-34) on the basis of cAMP production. Sensitivity declines on the last day of pregnancy. The newborn kidney showed a higher response to PTH 3 h after birth than after 24 h. The basal adenylate cyclase activity in renal membranes of maternal kidney does not change. The sensitivity to PTH and to fluoride both decreased on day 18.5. A desensitization process of the PTH receptor A-C system has to be studied in order to explain these results.

PMID: 2545286 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2535802&dopt=Abstract

Endocrinology 1989 Jan;124(1):149-56

Regulation of cytosolic pH in bovine parathyroid cells: effect of fluoride.

Sugimoto T, Civitelli R, Ritter C, Slatopolsky E, Morrissey J.


Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.

In the present investigation, sodium fluoride (NaF) was employed to explore the role of guanine nucleotide-binding proteins (G-proteins), protein kinase-C, or cytosolic calcium [( Ca]i) in the regulation of cytosolic pH [( pH]i) in dispersed bovine parathyroid cells, using the pH-sensitive fluorescent dye BCECF. When cells acidified by nigericin in Na-free medium were resuspended in Na-containing buffer, [pH]i returned to basal levels. This recovery was blocked by continued removal of Na+ or the addition of amiloride. NaF (10 mM) increased [32P]phosphate incorporation into phosphatidylinositol bisphosphate, suggesting an increase in phosphatidylinositol bisphosphate turnover. NaF caused an initial acidification, followed by an alkaline recovery in a dose-dependent manner (1-10 mM). Amiloride blocked the NaF-induced alkaline recovery. The protein kinase-C activator phorbol 12-myristate 13-acetate (10(-7) M) caused cytosolic alkalinization, while the protein kinase-C inhibitor H7 (6 x 10(-5) M) significantly inhibited the NaF-induced alkaline recovery. Pertussis toxin (1 microgram/ml) did not affect the NaF-induced changes in [pH]i. Removal of extracellular Ca2+ with EGTA blocked the NaF-induced increase in [Ca]i and alkaline recovery. Ionomycin (5 x 10(-7) M) caused cytosolic alkalinization, but pretreatment with EGTA inhibited the ionomycin-induced cytosolic alkalinization. The present studies clearly demonstrated the presence of an amiloride-sensitive Na+/H+ exchanger in parathyroid cells. Our findings suggest that the NaF-induced cytosolic alkaline recovery was via two complementing pathways:
1) activation of protein kinase-C, followed by stimulation of a Na+/H+ exchanger, and
2) existence of extracellular calcium and/or an increase in [Ca]i.

PMID: 2535802 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2508110&dopt=Abstract

Abstract not available

Prog Clin Biol Res 1989;301:377-81

Dual effect of fluoride on endothelial prostacyclin production: a phospholipase C mediated phenomenon.

Van Geet C, Deckmyn H, Kienast J, Wittevrongel C, Vermylen J.

Centre for Thrombosis and Vascular Research, K.U. Leuven, Belgium.

PMID: 2508110 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2469075&dopt=Abstract

Prostate 1989;14(2):91-101

Phosphorylation status of nuclear and cytosolic androgen receptors in the rat ventral prostate.

Golsteyn EJ, Graham JS, Goren HJ, Lefebvre YA.

Department of Medical Biochemistry, University of Calgary, Alberta, Canada.

We demonstrate that endogenous phosphatases are active in cytosolic and nuclear androgen receptor fractions from the rat ventral prostate. Under our androgen binding assay conditions, the effect of acid phosphatase inhibitors (sodium fluoride, tartaric acid, sodium orthovanadate) on the endogenous phosphatases could be correlated with an increase in dihydrotestosterone (DHT) binding to fractions of partially purified cytosolic androgen receptor. In contrast, tetramisole, an alkaline phosphatase inhibitor, did not alter the binding of DHT to the same receptor fraction. Immunoprecipitation of androgen receptor fractions with polyclonal anti-phosphotyrosine antibody resulted in the recovery of [3H]-DHT binding activity from nuclear receptor fractions and partially purified cytosolic receptor fractions prepared from 20- to 24-hr castrated rats. In control fractions depleted of androgen receptor, negligible levels of binding activity were recovered following immunoprecipitation with the antibody. Therefore, acid phosphatases may be acting on phosphotyrosyl residues of the androgen receptor, thus playing a role in the dephosphorylation and inactivation of the androgen receptor.

PMID: 2469075 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2542461&dopt=Abstract

J Neurochem 1989 Jul;53(1):258-63

Aluminum increases agonist-stimulated cyclic AMP production in rat cerebral cortical slices.

Johnson GV, Li XH, Jope RS.

Department of Neurology, University of Alabama, Birmingham 35294.

The effects of AlCl3 on basal and stimulated cyclic AMP production in rat cerebral cortical slices were studied. AlCl3 (10-250 microM) had no effect on the cyclic AMP concentration in the absence of drugs that stimulate the synthesis of cyclic AMP. 2-Chloroadenosine (25-200 microM) significantly stimulated the synthesis of cyclic AMP in a concentration-dependent manner, and AlCl3 significantly potentiated this response at 50 and 100 microM 2-chloroadenosine. This effect of AlCl3 was dependent on preexposure of the slices to AlCl3 before addition of the agonist. The potentiation by AlCl3 of the 2-chloroadenosine-induced increase in cyclic AMP level was concentration dependent, with significant enhancement by 100 (142% of the control) and 250 (150% of the control) microM AlCl3. Lower concentrations of AlCl3 had no significant effect on the production of cyclic AMP stimulated by 2-chloroadenosine. AlCl3 also potentiated the isoproterenol-induced increase in cyclic AMP production. Forskolin-induced production of cyclic AMP was unaltered by the presence of AlCl3. These results demonstrate that AlCl3 can potentiate agonist-stimulated cyclic AMP production in a whole-cell brain preparation without the addition of fluoride. This may account for the previously reported aluminum-induced increase in cyclic AMP concentrations in rat brain in vivo.

PMID: 2542461 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2806975&dopt=Abstract

Ginekol Pol 1989 Mar;60(3):182-6

[Placental perfusion. Observations based on examinations made at the Institute of Obstetrics and Gynecological Diseases of the Medical academy in Lublin in the years 1975-1984]

[Article in Polish]

Zrubek H, Oleszczuk J.

The paper presents the authors' experience resulting from the research into placental perfusion. The use of perfusion technique depended on a working hypothesis. The authors use the method of perfusion of foetal circulation. They analysed vascular resistance on the foetal side of the placenta, glucose consumption, production of lactic acid and pyruvic acid. They also analysed Dolantine, serotonin, papaverin, orciprenalin, phenoterol, theophylline ethylenediamine, isoxysuprin, propranolol, sodium fluoride. Basing on the results of the investigation of substances stimulating the betaadrenergic receptor, the authors came to the conclusion that there exists primary and secondary anoxia syndrome.

PMID: 2806975 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2491850&dopt=Abstract

NOTE: AG Gilman, co-author of this report, shared the 1994 Nobel Prize for the discovery of "G-proteins and the role of these proteins in signal transduction in cells."

J Biol Chem 1989 Jan 5;264(1):409-18

Expression of Gs alpha in Escherichia coli. Purification and properties of two forms of the protein.

Graziano MP, Freissmuth M, Gilman AG.

Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas 75235.

Cloning of complementary DNAs that encode either of two forms of the alpha subunit of the guanine nucleotide-binding regulatory protein (Gs) that stimulates adenylyl cyclase into appropriate plasmid vectors has allowed these proteins to be synthesized in Escherichia coli (Graziano, M.P., Casey, P.J., and Gilman, A.G. (1987) J. Biol. Chem. 262, 11375-11381). A rapid procedure for purification of milligram quantities of these proteins is described. As expressed in E. coli, both forms of Gs alpha (apparent molecular weights of 45,000 and 52,000) bind guanosine 5'-(3-O-thio)triphosphate stoichiometrically. The proteins also hydrolyze GTP, although at different rates (i.e. 0.13.min-1 and 0.34.min-1 at 20 degrees C for the 45- and the 52-kDa forms, respectively). These rates reflect differences in the rate of dissociation of GDP from the two proteins. Both forms of recombinant Gs alpha have essentially the same kcat for GTP hydrolysis, approximately 4.min-1. Recombinant Gs alpha interacts functionally with G protein beta gamma subunits and with beta-adrenergic receptors. The proteins can also be ADP-ribosylated stoichiometrically by cholera toxin. This reaction requires the addition of beta gamma subunits. Both forms of recombinant Gs alpha can reconstitute GTP-, isoproterenol + GTP-, guanosine 5'-(3-O-thio)triphosphate-, and fluoride-stimulated adenylyl cyclase activity in S49 cyc- membranes to maximal levels, although their specific activities for this reaction are lower than that observed for Gs purified from rabbit liver. Experiments with purified bovine brain adenylyl cyclase indicate that the affinity of recombinant Gs alpha for adenylyl cyclase is 5-10 times lower than that of liver Gs under these assay conditions; however, the intrinsic capacity of the recombinant protein to activate adenylyl cyclase is normal. These findings suggest that Gs alpha, when synthesized in E. coli, may fail to undergo a posttranslational modification that is crucial for high affinity interaction of the G protein with adenylyl cyclase.

PMID: 2491850 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2496748&dopt=Abstract

NOTE: AG Gilman, co-author of this report, shared the 1994 Nobel Prize for the discovery of "G-proteins and the role of these proteins in signal transduction in cells."

Biochemistry 1989 Jan 24;28(2):611-6

G protein beta gamma subunits from bovine brain and retina: equivalent catalytic support of ADP-ribosylation of alpha subunits by pertussis toxin but differential interactions with Gs alpha.

Casey PJ, Graziano MP, Gilman AG.

Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas 75235.

We have examined the ability of the beta gamma subunits of guanine nucleotide binding regulatory proteins (G proteins) to support the pertussis toxin (PT) catalyzed ADP-ribosylation of G protein alpha subunits. Substoichiometric amounts of the beta gamma complex purified from either bovine brain G proteins or the bovine retinal G protein, Gt, are sufficient to support the ADP-ribosylation of the alpha subunits of Gi (the G protein that mediates inhibition of adenylyl cyclase) and Go (a G protein of unknown function) by PT. This observation indicates that ADP-ribosylated G protein oligomers can dissociate into their respective alpha and beta gamma subunits in the absence of activating regulatory ligands, i.e., nonhydrolyzable GTP analogues or fluoride. Additionally, the catalytic support of ADP-ribosylation by bovine brain beta gamma does not require Mg2+. Although the beta gamma subunit complexes purified from bovine brain G proteins and the beta gamma complex of Gt support equally the ADP-ribosylation of alpha subunits by PT, there is a marked difference in their abilities to interact with Gs alpha. The enhancement of deactivation of fluoride-activated Gs alpha requires 25-fold more beta gamma from Gt than from brain G proteins to produce a similar response. This difference in potency of beta gamma complexes from the two sources was also observed in the ability of beta gamma to produce an increase in the activity of recombinant Gs alpha produced in Escherichia coli.

PMID: 2496748 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2925163&dopt=Abstract

Hepatology 1989 Apr;9(4):570-81

Biochemical effects and zonal heterogeneity of peroxisome proliferation induced by perfluorocarboxylic acids in rat liver.

Just WW, Gorgas K, Hartl FU, Heinemann P, Salzer M, Schimassek H.

Department of Biochemistry I, University of Heidelberg, Federal Republic of Germany.

Rats were treated for 5 to 14 days with perfluoroacetate, perfluorobutyrate and perfluorooctanoate. Alterations in hepatic morphology with special reference to the peroxisomal compartment were investigated by light and electron microscopy following cytochemical staining of catalase activity with the alkaline 3,3'-diaminobenzidine medium. All three compounds induced hepatomegaly and peroxisome proliferation. Perfluorobutyrate and perfluorooctanoate were found to be more active than perfluoroacetate. Perfluorooctanoate-induced peroxisome proliferation was more prevalent in centrilobular than in periportal hepatocytes. Peroxisomes in centrilobular liver cells frequently were of round shape, exhibited diameters of up to 1.5 microns and were predominantly located within smooth endoplasmic reticulum-glycogen areas. In periportal cells, however, clusters of polymorphous peroxisomes ranging from 250 to 1,100 nm in diameter were observed at the periphery of smooth endoplasmic reticulum-glycogen regions. Peroxisome proliferation was accompanied by a change of peroxisomal and mitochondrial enzyme activities, in particular an increase in peroxisomal palmitoyl-CoA oxidation. Significant alterations in the concentration of peroxisomal matrix and membrane polypeptides were also noted. Within the first 2 days, perfluorooctanoate treatment exerted a strong hypolipidemic activity and both compounds perfluorooctanoate and perfluorobutyrate raised the level of hepatic free acid-soluble CoA nearly 10-fold as compared with control livers. The results suggest perfluorinated carboxylic acids to be model substances suitable to correlate biochemical and morphological parameters with the zonal heterogeneity of the peroxisomal compartment in rat liver. Due to the manifold hepatic effects, contact of humans with perfluorinated carboxylic acids or their metabolic precursors may represent a severe health risk.

PMID: 2925163 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2537798&dopt=Abstract

Inflammation 1989 Feb;13(1):47-58

Fluoride activation of neutrophils: similarities to formylmethionyl-leucyl-phenylalanine.

Gabler WL, Creamer HR, Bullock WW.

Department of Biochemistry, Oregon Health Sciences University, Portland 97201.

Fluoride induced degranulation of both primary and specific granules from neutrophils pretreated with cytochalasin B. There was a similarity in the dependency on extracellular Ca2+ for fluoride- and for FMLP-stimulated O2- generation and degranulation. Pertussis toxin, but not cholera toxin, inhibited FMLP and fluoride activation of neutrophils, while neither toxin affected PMA activation of these cells. These results suggest that fluoride and FMLP activate neutrophils through a common Ca2+-dependent and pertussis toxin-sensitive pathway.

PMID: 2537798 [PubMed - indexed for MEDLINE]

[Note from FAN:
Definition of neutrophil, neutrophile.
1. a mature white blood cell in the granulocytic series, formed by bone marrow and released into the circulating blood, where they normally represent from 54% to 65% of the total number of leukocytes... The precursors of neutrophils in order of increasing maturity, are: myeloblasts, promyelocytes, myelocytes, metamyelocytes, and band forms.
2. any cell or tissue that manifests no special affinity for acid or basic dyes, i.e., the cytoplasm stains approximately equally with either type of dye. [neutro- G. philos, fond]
Ref: Stedman's Concise Medical Dictionary for the Health Professions. Illustrated 4th Edition. Ed. JH Dirckx. 2001.


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2753522&dopt=Abstract

Inflammation 1989 Jun;13(3):317-28

Effect of fluoride on movement of concanavalin A-acceptor molecules of human neutrophils.

Gabler WL, Mugrditchian M, Creamer HR, Bullock WW.

Department of Biochemistry, Oregon Health Sciences University, School of Dentistry, Portland 97201.

The effects of fluoride (F) on neutrophil protuberance formation and induced Con A acceptor molecule migration were assessed microscopically. Below 5 mM, F had little effect on acceptor migration, while it markedly inhibited formation of colchicine-induced protuberances. The anion also increased the rate at which preformed protuberances regressed. Since protuberance formation is enhanced by disassembly of microtubules, these data suggest that F promotes and/or stabilizes microtubule assembly. Microtubule assembly is favored by binding of GTP to tubulin subunits, while GDP binding favors disassembly of microtubules. Since F binds with GDP, forming a new complex that mimics GTP, the anion would be expected to enhance microtubule assembly. Over the same F concentration range, the anion failed to inhibit acceptor polarization, but did inhibit cytochalasin B-enhanced dispersion of prepolarized Con A acceptors, implying that, at low concentrations, F also affected microfilament cycling. Concentrations of F in excess of 5 mM inhibited acceptor migration as well as protuberance formation. At 20 mM, the anion abolished both events, yet at this same concentration F induced neutrophil superoxide generation and degranulation, suggesting that acceptor migration is not a prerequisite for these two neutrophil effector activities.

PMID: 2753522 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2808407&dopt=Abstract

J Biol Chem 1989 Nov 15;264(32):19017-21

Characterization of the aluminum and beryllium fluoride species bound to F-actin and microtubules at the site of the gamma-phosphate of the nucleotide.

Combeau C, Carlier MF.

Laboratoire d'Enzymologie du Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.

Aluminum fluoride and beryllium fluoride complexes have previously been shown to bind tightly to F-ADP-actin and GDP-microtubules in competition with Pi and to mimic the XDP-Pi transient state of the polymerization. The structure of the bound complexes is investigated here in further detail. Using a fluoride ion-specific electrode, the number of fluoride atoms per aluminum or beryllium atom in the bound complex could be determined. The results indicate that AIF-4 and either BeF2(OH)-.H2O or BeF3-.H2O are the tightly bound species in both F-actin and microtubules. The dependences of the binding on pF and pH are consistent with this conclusion. The possible geometries of aluminum and beryllium fluorides in the gamma-phosphate subsite of the nucleotide are discussed in correlation with the catalytic mechanism of nucleotide hydrolysis.

PMID: 2808407 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2719934&dopt=Abstract

Biochemistry 1989 Feb 21;28(4):1783-91

Mechanism of GTP hydrolysis in tubulin polymerization: characterization of the kinetic intermediate microtubule-GDP-Pi using phosphate analogues.

Carlier MF, Didry D, Simon C, Pantaloni D.

Laboratoire d'Enzymologie du CNRS, Gif-sur-Yvette, France.

Beryllium fluoride (BeF3-) has previously been shown to bind tightly to microtubules as a structural analogue of Pi and to mimic the GDP-Pi transient state in tubulin polymerization [Carlier, M.-F., Didry, D., Melki, R., Chabre, M., & Pantaloni, D. (1988) Biochemistry 27, 3555-3559]. The interaction of BeF3- with tubulin is analyzed here in greater detail. BeF3- binds to and dissociates from microtubule GDP subunits at very slow rates (k+ congruent to 100 M-1 s-1; k- congruent to 6 x 10(-4) s-1), suggesting that a slow conformation change of tubulin, linked to the stabilization of the microtubule structure, follows BeF3- binding. The possibility is evoked that BeF3- acts as a transition-state analogue in the GTPase reaction of tubulin. BeF3- does not bind to dimeric nor to oligomeric GDP-tubulin with high affinity. Substoichiometric binding of BeF3- to microtubules provides extensive stabilization of the structure. An original mechanistic model that accounts for the data is proposed. The kinetic parameters for microtubule elongation in the presence of GTP- and GDP-tubulin with and without BeF3- have been determined. Data support the following views: (i) Microtubules at steady state and in a regime of slow growth in the presence of GTP are stabilized by a cap of GDP-Pi subunits functionally similar to GDP-BeF3 subunits. (ii) In the presence of BeF3-, microtubules elongate from GDP-tubulin within the following sequence of reactions: initial nonproductive binding of GDP-tubulin to microtubule ends is followed by the binding of BeF3- and the associated conformation change allowing sustained elongation.

PMID: 2719934 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2767363&dopt=Abstract

Fundam Appl Toxicol 1989 Jul;13(1):79-86

The effects of inhalation exposure to sulfuryl fluoride on fetal development in rats and rabbits.

Hanley TR Jr, Calhoun LL, Kociba RJ, Greene JA.

Mammalian and Environmental Toxicology Research Laboratory, Dow Chemical Company, Midland, Michigan 48674.

Sulfuryl fluoride is a fumigant insecticide used for soils and permanent structures. Pregnant Fischer 344 rats and New Zealand White rabbits were exposed to 0, 25, 75, or 225 ppm of sulfuryl fluoride vapor via inhalation for 6 hr/day on Days 6-15 and 6-18 of gestation, respectively. Among rats, maternal water consumption was increased in the 225 ppm exposure group, but there were no indications of embryotoxicity, fetotoxicity, or teratogenicity in any of the exposed groups. Among rabbits, maternal weight loss during the exposure period (Days 6-18) was observed in the 225 ppm group. Decreased fetal body weights, considered secondary to maternal weight loss, were also observed at 225 ppm. However, no evidence of embryotoxicity or teratogenicity was observed among rabbits in any exposure group. Thus, inhalation exposure to sulfuryl fluoride was not teratogenic in either rats or rabbits exposed to levels of up to 225 ppm, and fetotoxic effects (reduced body weights) were observed among fetal rabbits only at an exposure level that produced maternal weight loss.

PMID: 2767363 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2783043&dopt=Abstract

Arch Oral Biol 1989;34(2):103-7

Studies on the transmembrane migration of fluoride and its effects on proliferation of L-929 fibroblasts (L cells) in vitro.

Kawase T, Suzuki A.

Department of Pharmacology, Niigata University School of Dentistry, Japan.

A decrease in the pH of the medium facilitated fluoride (F-) influx but depressed its efflux, which is consistent with the hypothesis that simple diffusion of hydrogen fluoride (HF) contributes to F- migration across the cell membrane. Long-term exposure to F- (greater than 1 mM) induced F- accumulation and, as a result, inhibited cell proliferation. In contrast, short-term exposure to F- (greater than 1 mM), followed by careful washing, did not inhibit cell proliferation but rather stimulated it. Moreover, this stimulatory effect was enhanced by 1 microM Al3+ and was inhibited by 1 microM H-7, a specific inhibitor of protein kinase C. Thus F- may stimulate cell proliferation by activating protein kinase C through GTP-binding protein. The stimulatory effect of F- on cell proliferation, which is usually hidden by its inhibitory effect, can be observed by preventing the accumulation of F- in the cytoplasm.

PMID: 2783043 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2556178&dopt=Abstract

Br J Ind Med 1989 Nov;46(11):782-6

Characteristics of alveolar cells and soluble components in bronchoalveolar lavage fluid from non-smoking aluminium potroom workers.

Eklund A, Arns R, Blaschke E, Hed J, Hjertquist SO, Larsson K, Lowgren H, Nystrom J, Skold CM, Tornling G.

Department of Thoracic Medicine, Karolinska Hospital, Stockholm, Sweden.

Aluminium potroom workers have been reported to develop severe pneumoconiosis and bronchial hyperreactivity. The influence of inhalation of aluminium oxide and fluorides on the alveolar milieu was studied by bronchoalveolar lavage (BAL) in 14 male non-smoking potroom workers; 28 non-smoking healthy volunteers served as controls. The total numbers, concentrations, and proportions of various alveolar cells did not differ between the groups. The concentrations of albumin and fibronectin in BAL fluid were significantly higher (p less than 0.01 for both) in the exposed workers, reflecting an increased alveolar capillary permeability and an activation of alveolar macrophages (AMs). The concentration of angiotensin converting enzyme, another AM marker, was, however, decreased (p less than 0.01) in the workers. The concentration of hyaluronan, a fibroblast marker, did not differ between the groups. AMs from workers had a decreased capacity (p less than 0.05) to interact with yeast C3b particles but not to ingest them. The expression of HLA-DR and OKM1 on the cell surfaces of AMs were equal in the two groups. The BAL findings were not accompanied by restrictive lung disease in the workers. The fact that only a discrete alveolitis was found in the potroom workers may be due to a low grade of exposure to alumina and fluorides and to frequent use of respiratory protection equipment.

PMID: 2556178 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2777755&dopt=Abstract

J Biochem (Tokyo) 1989 Jul;106(1):8-10

Aluminum enhances the stimulatory effect of NaF on prostaglandin E2 synthesis in a clonal osteoblast-like cell line, MOB 3-4, in vitro.

Kawase T, Ishikawa I, Orikasa M, Suzuki A.

Department of Pharmacology, Niigata University School of Dentistry.

The effect of NaF on prostaglandin E2 (PGE2) synthesis in a clonal osteoblast-like cell line, MOB 3-4, was examined in the presence of Al3+. The MOB 3-4 cell line, which was derived from neonatal mouse calvaria, displays many osteoblastic characteristics, including the biosynthesis of PGE2. In the absence of Al3+, 1 mM NaF increased PGE2 synthesis (per well) to about 340% of the control level, whereas NaF at lower concentrations (below 0.1 mM) did not show such a significant effect. In the presence of 10 microM Al3+, NaF concentrations ranging from 0.01 to 1 mM increased PGE2 synthesis in a dose-dependent manner, though 10 microM Al3+ had no effect by itself. Similar effects were observed on alkaline phosphatase (ALP) activity per well, but a stimulatory effect of NaF on protein synthesis was observed only in the presence of 10 microM Al3+. These data demonstrated that PGE2 synthesis per protein was increased by NaF alone, and this effect was markedly enhanced by the addition of AlCl3. ALP activity per protein was, however, significantly increased by NaF in the absence of AlCl3. Taken together with our previous finding that Al3+ enhances the NaF-induced Ca2+ mobilization in MOB 3-4 cells, these results suggest that F- combined with Al3+ (i.e., AlF4-) is a more potent stimulator of PGE2 synthesis in cells than F- alone, and that the AlF4- -enhanced PGE2 synthesis may be caused by an increase in cytosolic free Ca2+ concentration during activation of the G protein by AlF4-.

PMID: 2777755 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2771869&dopt=Abstract

Pharmacol Toxicol 1989 May;64(5):426-8

Fluoride-induced cytoplasmic acidification: possible role of protein kinase C in BCECF-loaded L929 cells.

Kawase T, Suzuki A.

Department of Pharmacology, Niigata University School of Dentistry, Japan.

The effect of fluoride on cytoplasmic pH (pHi) in L929 cells was investigated by using a fluorescent pH indicator, BCECF. Fluoride decreased pHi in a dose-dependent manner. This cytoplasmic acidification was composed of two phases: 1) a rapid decrease in pHi occurring within seconds, and 2) a slow decrease in pHi occurring 1-2 min. after stimulation with fluoride. The phase one decrease in pHi at external pH (pHe) 7.7 was more rapid than that at pHe 6.8, whereas the phase two decrease at pHe 7.7 was slower than that at pHe 6.8. In addition, both in the protein kinase C-inhibited and depleted cells, the fluoride-acidified pHi gradually returned to the resting pHi level in phase two, though the initial cytoplasmic acidification (i.e. phase one) was not affected. These results suggest that the fluoride-induced cytoplasmic acidification is dependent upon pHe and is sustained by the protein kinase C-dependent Na+/H+ exchange.

PMID: 2771869 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2677687&dopt=Abstract

Monogr Oral Sci 1989;13:1-160

The metabolism and toxicity of fluoride.

Whitford GM.

Department of Oral Biology, Medical College of Georgia, Augusta.

Publication Types: Review Review, Academic

PMID: 2677687 [PubMed - indexed for MEDLINE]


Back to the top

Return to FAN's Pesticide Homepage