Influence of cystein deficiency on the inhibition of hepatic microsomal detoxication by methyl mercury in two rat strains.

Two rat strains, Wistar, strain R and Sprague--Dawley, were subjected to cystein deficiency and methyl mercury pretreatment, both separately and in combination, after which the hepatic microsomal N- and C-oxygenation of N,N-dimethylaniline (DMA) was studied. Cystein deficiency caused a reduction in C-oxygenation in strain R microsomes, and this reduction was nearly doubled by methyl mercury pretreatment of the depleted rats. Methyl mercury pretreatment per se of strain R rats on the standard diet gave no effect. By contrast microsomes from cystein deficient SpD rats showed no statistically significant decrease in C-oxygenation, and cystein deficiency did not further enhance the inhibitory effect obtained with methyl mercury pretreatment alone. N-oxygenation was not significantly affected by any treatment of the two strains.