The effects of cadmium on the energy metabolism of mitochondria were studied with isolated hepatocytes and rat liver mitochondria. It was found that cadmium inhibited the respiration of both isolated hepatocytes and mitochondria and decreased the ATP content of isolated hepatocytes. This inhibition of energy metabolism of mitochondria was highly related to the nonviability of isolated hepatocytes caused by cadmium. The site of electron transport of the mitochondrial respiratory chain blocked by cadmium was located between cytochrome b and flavoproteins. The uncoupling effects of mitochondrial oxidative phosphorylation caused by cadmium may have resulted from changes in the fluidity and permeability of the mitochondrial membrane. (c) 1990 Academic Press. Inc. The effects of cadmium on the energy metabolism of mitochondria were studied with isolated hepatocytes and rat liver mitochondria. It was found that cadmium inhibited the respiration of both isolated hepatocytes and mitochondria and decreased the ATP content of isolated hepatocytes. This inhibition of energy metabolism of mitochondria was highly related to the nonviability of isolated hepatocytes caused by cadmium. The site of electron transport of the mitochondrial respiratory chain blocked by cadmium was located between cytochrome b and flavoproteins. The uncoupling effects of mitochondrial oxidative phosphorylation caused by cadmium may have resulted from changes in the fluidity and permeability of the mitochondrial membrane. (c) 1990 Academic Press. Inc.