[The liver monooxygenase system in nutritional deficiency in rats in early ontogeny]

Young rats aged 14 days were subjected to malnutrition during 3.7 and 14 days. Activity of the main microsomal enzymes and lipid peroxidation (LPO) products in the microsomal cytosol fraction of the liver was studied in the test and control (aged 17.21 and 28 days) animals. It has been found that constant malnutrition leads to elevation of amidopyrine demethylase activity and inhibition of c-reductase and aniline hydrolase NADP.H cytochrome activities, as well as to a decreased content of protein and cytochrome P-450 in the liver. At the same time the levels of conjugated dienes and diene-ketones in the microsomal-cytosol fraction of the liver significantly rise that denotes activation of LPO in the microsomal membranes. It has been suggested that the suppression of the monooxygenase system function during malnutrition induces inhibition of the intensity of biotransformation of xenobiotics, including drugs which is responsible for intensification of pharmacodynamics and toxicity of the latter. These conditions should be taken into consideration during drug therapy in patients with malnutrition.