Effects of cyanide on selenium metabolism in rats.

Adult male rats were given drinking water containing either 0 or 150 ppm cyanide for 2 weeks. They were then injected with 5 microCi 75Se-selenite, and excretion of radioactivity in urine and feces was determined. No difference in excretion of 75Se occurred during the rapid phase, but the cyanide-treated rats (T1/2 28 days) excreted significantly more 75Se in urine than control (T1/2 38 days) rats. Cyanide had no effect on excretion of 75Se in feces or on the distribution of 75Se in cytosolic proteins in liver, kidney, muscle or testes. In a second experiment weanling male rats were given water with either 0 or 150 ppm cyanide and were killed for glutathione peroxidase assay and selenium analysis in blood, kidney, liver, muscle and testes after 3, 6 or 9 weeks of treatment. Glutathione peroxidase activity and selenium concentrations were significantly reduced by cyanide in all tissues except testes.