Interactions of dietary methionine, lead and lindane in rats

The effects of dietary methionine on lead and lindane toxicities in rats were studied in two experiments. Rats were fed methionine-deficient (60% of requirement) or methionine-sufficient soy protein-based diets with lead acetate added (10,000 mg/kg Pb) and treated with a single dose of lindane (25% of LD50 or 88 mg/kg, p.o.) in both experiments. In experiment I, all rats were fed ad libitum. In experiment II, rats fed the methionine-sufficient diet were pair-fed to rats fed the methionine-deficient diet. In experiments I and II, the methionine-sufficient and the methionine-deficient rats had decreased final body weights, increased liver weights, decreased hematocrits, and no changes in glutathione S-transferase activity when compared to a control group. Lead + lindane treatments increased liver glutathione levels in the methionine-sufficient and methionine-deficient rats in both experiments. However, in experiment II (pair-feeding), the methionine-sufficient rats had a much greater level of liver glutathione than the methionine-deficient rats. The methionine status of the animals seems to be an important factor in determining the liver glutathione level of pair-fed rats treated with lead + lindane.