title: Effect of dietary fluoride on selenite toxicity in the rat.
abstract: Three factorial experiments were conducted to determine if high dietary fluoride (F) would inhibit selenite toxicity in rats. Initially, three levels of selenite (0.05, 3, and 5 mg/kg diet) were matched against three levels of F (2, 75, and 150 mg/kg diet). Fluoride failed to prevent the depressive effect of selenite on 8-wk food intake and body wt gain. Selenium (Se) concentration of plasma and kidney and enzymatic activity of whole blood glutathione peroxidase (GSH-Px) were also unaffected by F. Liver Se concentration, however, was slightly (12%) but significantly (p < 0.025) reduced when the highest F and Se levels were combined. Fluoride (150 mg/kg) appeared to reduce liver selenite toxicity (5 mg/kg). Therefore, further study focused on liver histology with treatments that eliminated the middle levels of selenite and F. Fluoride prevented the hepatic necrosis seen in selenite-toxic rats. Similar histological lesions were not observed for kidney or heart. Fluoride partially (26%) but significantly (p < 0.025) reduced thiobarbituric-reactive substances in selenite-toxic rats, but there was no F effect on intracellular distribution of liver Se, glutathione levels in liver and kidney, or on liver xanthine oxidase activity. Overall, the protective effect of F on selenite toxicity appears to be confined to liver pathology. The exact mechanism for this effect, however, remains unclear.
authors.affiliation: Department of Nutrition and Food Management, Oregon State University, Corvallis 97331.
authors.forename: Q
authors.initials: Q
authors.lastname: Yu
authors.forename: F L
authors.initials: FL
authors.lastname: Cerklewski
authors.forename: P D
authors.initials: PD
authors.lastname: Whanger
authors.forename: O
authors.initials: O
authors.lastname: Hedstrom
authors.forename: J W
authors.initials: JW
authors.lastname: Ridlington
mesh_terms: D000818:Animals; D056486:Chemical and Drug Induced Liver Injury; D004032:Diet; D004435:Eating / Q000187:drug effects; D005459:Fluorides / Q000008:administration & dosage / Q000494:pharmacology*; D005979:Glutathione Peroxidase / Q000097:blood; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008107:Liver Diseases / Q000178:diet therapy* / Q000473:pathology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012643:Selenium / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000633:toxicity*
chemical_list: D005979:Glutathione Peroxidase; D012643:Selenium; D005459:Fluorides