Abstract
The combined effect of cadmium on the hepatic microsomal monooxygenases was investigated by i.p. injection at a dose of 0.5 or 1.0 mg Cd/kg or by ingestion of diet containing 200 ppm Cd in the rats fed with normal or PCB (50 ppm) diet. The i.p. administration of cadmium reduced the amount of cytochromes P-450 and b5, and the activities of aminopyrine N-demethylase and p-nitroanisole O-demethylase in normal diet group, but did not counteract the effect of PCB. The feeding of cadmium-containing diet enhanced the activity of covalently binding of bromobenzene with microsomal protein at 1 week and the inducing effect of PCB on aniline hydroxylase. However, cadmium feeding for 5 weeks counteracted the inducing effect of PCB on the covalently binding of bromobenzene. In conclusion, the effect of cadmium by oral administration was not so much on the hepatic microsomal monooxygenases.
