[Effect of hepatectomy on liver adenylate cyclase activity in rats of various ages].

Age-dependent differences were found in patterns of rat liver adenylate cyclase system in response to hepatectomy-induced proliferation. After hepatectomy a decrease in basic activity of adenylate cyclase and in content of cAMP were observed only in adult animals. At the same time, the epinephrine-stimulated enzymatic activity was decreased in old hepatectomized rats as compared with intact animals. These alterations in regulatory activity of the adenylate cyclase system appear to affect the intensity of DNA biosynthesis and the functional activity of regenerating liver tissue of old rats.