Selenium deficiency and detoxication functions in the rat: short-term effects of cadmium.
Weanling rats were fed a Torula yeast-based selenium-deficient diet with or without supplementation of sodium selenite (0.2 ppm selenium) in the drinking water. After 5-6 weeks on the diet regimens, the liver glutathione peroxidase activity of the selenium-deficient groups had decreased to about 1% of the supplemented groups, and the rats were then used in experiments. Cadmium-induced effects on the drug-metabolizing system of the liver were measured as the microsomal capacity to perform N- and C-oxygenation of N, N-dimethylaniline. Cadmium in vitro caused a decrease of the cytochrome P-450-dependent C-oxygenation. This effect tended to be more prominent in the selenium-deficient groups. On the other hand, N-oxygenation was increased when cadmium was added in vitro, and no significant difference was found between selenium-deficient and -supplemented groups. However, as was found for the capacity to perform C-oxygenation, there was a tendency for lower N-oxygenation in the selenium-deficient rat. Lipid peroxidation, measured as thiobarbituric acid reactive substances in liver homogenates, was higher in selenium-deficient groups after in vivo treatment or in vitro addition of cadmium, and preincubation or phenobarbital induction enhanced this selenium-dependent difference. Although, the selenium-deficient rat seems more susceptible to cadmium-induced disturbances, 5-6 weeks of selenium deficiency was not enough to cause prominent impairment on the drug-metabolizing system as measured here and with the doses used in the present study.
D000814:Aniline Compounds / Q000378:metabolism; D000818:Animals; D002104:Cadmium / Q000633:toxicity*; D005979:Glutathione Peroxidase / Q000032:analysis; D008658:Inactivation, Metabolic / Q000187:drug effects*; D008054:Lipid Peroxides / Q000378:metabolism; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D006899:Mixed Function Oxygenases / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D012643:Selenium / Q000172:deficiency*
D000814:Aniline Compounds; D008054:Lipid Peroxides; D002104:Cadmium; C015157:N,N-dimethylaniline; D006899:Mixed Function Oxygenases; D005979:Glutathione Peroxidase; D012643:Selenium