Effects of mercury on cytochrome P-450 levels in mouse hepatic microsomes

Abstract

Equivalent doses (6.02 μg Hg2+/g body wt) of mercuric chloride (HgCl2) and mercuric sulfide (HgS) were administered orally to mice, after which the levels of cytochrome P-450 in hepatic microsomes were analyzed. Both HgCl2 and HgS caused an initial significant depression in the levels of cytochrome P-450 relative to the controls, but only the HgCl2-treated mice exhibited sustained depression. Hepatic microsomal protein content was likewise significantly lower for a sustained period in the HgCl2-treated mice but was lower only initially in the HgS-treated mice. These results suggest that the difference between the effects of HgS and HgCl2 are attributable to the different solubilities of the two compounds. The solubilities of HgS and HgCl2 indirectly govern their effects on cytochrome P-450 levels by affecting the extent to which Hg2+ accumulates in the liver.