EFFECT OF CADMIUM ON HEPATIC-MICROSOMAL MONOOXYGENASE ACTIVITIES IN GUINEA-PIGS WITH LOW AND HIGH ASCORBIC-ACID INTAKE

The influence of in vivo administration of cadmium on hepatic microsomal cytochrome P-450 and cytochrome b(5) content, aniline hydroxylase, p-nitroanisole O-demethylase, and NADPH-cytochrome c reductase activities was investigated in guinea pigs with low (2 mg/animal/day) and high (100 mg/animal/day) ascorbic acid intake. Male guinea pigs received 10 mg Cd/L drinking water for 5 and 12 weeks. Cadmium administration resulted in significant decreases in cytochrome P-450 content and NADPH-cytochrome c reductase activity in the group of guinea pigs with low ascorbic acid intake, while the decreases were less evident in guineapigs with high ascorbic acid intake. The activities of aniline hydroxylase and O-demethylase were not apparently changed by Cd administration, except for the group of guinea pigs with high ascorbic acid intake in 12th week of cadmium treatment, when increased activities were observed. These findings suggest that hepatotoxic effect of cadmium manifested by inhibition of hepatic microsomal metabolism may be in part beneficially moderated by enhanced ascorbic acid intake.