Effects of some toxic metals on hepatic microsomal mixed function oxidase system of the rat

Abstract

In this study the authors studied acute effects of 5 toxic metals (cadmium, mercury, lead, chromium and arsenic) and a lead-zinc ore on microsomal mixed function oxidase system of the male rat. The results showed that a single dose of cadmium acetate (2.4 mg/kg I.P.) 72 hours following treatment, and a single dose mercuric chloride (2.0 mg/kg I.P.), lead acetate (100 mg/kg I.P.) or lead-zinc ore (1100 mg/kg I.P.) 24 hours following treatment inhibited microsomal mixed function oxidase activity of the male rat liver. A single dose of sodium chromate (17 mg/kg I.P.) or sodium arsenite (4.0 mg/kg I.P.) did not exhibit any effect on microsomal mixed function oxidase activity 24 hours following treatment. In vitro the results showed that cadmium, lead, mercury and chromium could inhibit the activity of hepatic microsomal aniline hydroxylase and decrease the concentration of hepatic microsomal cytochrome P-450 directly. The mechanisms through which cadmium, lead, and chromium depressed hepatic microsomal mixed function oxidase activity are primarily discussed.

Keywords

cadmium / lead / mercury / chromium / arsenic / lead-zinc ore / microsomal mixed function oxidase

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