[Relation of changes in the content and activity of rat liver microsomal cytochrome P-450 to the intensification of lipid peroxidation under stress].

The content of cytochromes and aminopyrine demethylase activity of rat liver microsomes were studied after 3 hours of swimming, adrenaline administration, and immobilization of the animals. Immobilization and swimming resulted in a short-term 19-25% decrease in the content of cytochrome P-450. Administration of adrenaline entailed a more prolonged and appreciable reduction in the content of both cytochrome P-450 and cytochrome b5. These changes were preceded by intensification of lipid peroxidation (LPO) in the liver. After the exposures described the pattern of changes in demethylase activity of microsomes was more complex than the changes in the content of cytochrome P-450. It is assumed that the decreased content of cytochrome P-450 in the endoplasmic liver reticulum is a non-specific body reaction to stress exposures and that this reaction is related to the intensification of LPO in animal tissues.