[Effect of low concentrations of nitrosodimethylamine on the functional state of enzymatic systems in the endoplasmatic reticulum of the rat liver].

Functional state of enzymatic systems in rat liver endoplasmic reticulum was studied. Content of cytochromes P-450 and b5 as well as activities of UDP-glucuronyl transferase, glucose-6-phosphatase, beta-glucuronidase, acetylesterase, inosine-5-diphosphatase were evaluated after permanent administration of nitrosodimethylamine within 2, 5 and 10 months at concentrations of 0.1, 1.0 and 10.0 mg/l. Content of the cancerogene active metabolites in liver cells was shown to be responsible for impairment of the functional state of microsomal enzymatic systems and was also related to intensity and duration of the nitrosodimethylamine effect. The level of these cancerogene metabolites in liver cells depended on rates of the cancerogene oxidation in the monooxygenase system and elimination of active products. At the same time, the rate of nitrosodimethylamine metabolism correlated with the doses of the substance administered into rats.