Inductive Effects of Methyl Mercury on the Hepatic Microsomes of Mice

: 36 male NMRI mice weighing about 17 g each were divided into groups of 12 animals. Groups 1 and 2 were treated once intraperitoneally with methyl mercury nitrate. Group 1 received 0.3 mg Hg/kg and group 2 10 mg Hg/kg in 0.5 ml water; the third group, which was kept as control, was treated intraperitoneally with 0.5 ml water. After 7 days all the mice were sacrificed. The mean total liver protein was found to be significantly decreased in group 2. The mean liver microsomal protein was significantly (P < 0.01) increased in groups 1 (P < 0.01) and 2 (P < 0.02) as compared to the controls. The mean cytochrome P-450 concentration of the liver microsomes was also significantly increased in groups I (P < 0.001) and 2 (P < 0.01) as compared to the controls and in group 1 (P < 0.01) as compared to group 2. The mean liver microsomal NADPH-cytochrome c-reductase activity was significantly greater in group 2 (P < 0.001) and in group 1 (P < 0.01) than in the controls. The mean NADPH-cytochrome c-reductase activity of group 2 was also significantly greater than the mean activity in group 1 (P < 0.02).