Effect of mercuric chloride on microsomal enzyme system in mouse liver.

The effect of mercuric chloride (2 mg/kg) on microsomal enzymes in mouse liver was investigated in phenobarbital- and 3-methylcholanthrene-induced hepatic microsomes. The metal caused an increase in total microsomal protein in noninduced controls, whereas no significant changes were observed in induced microsomes. Cytochrome P-450 was decreased in each case, which suggests that the metal may cause enzyme degradation. p-Nitroanisole O-demethylase was increased fivefold with both inducers. In addition, mercuric chloride increased the O-demethylase activity in relation to microsomal protein. The effect of the metal on ethylmorphine N-demethylase activity was slightly inhibitory.