A study of mechanisms of post-irradiation changes in adenylate-cyclase activity

Hormone-stimulated adenylate-cyclase activity (via beta-adrenergic receptors) is reduced after in vitro irradiation of plasma membranes of frog erythrocytes, at a dose (650 Gy) which does not change the number of beta-adrenergic receptors but causes an oxidative degradation of membrane lipids. Peroxidation of membrane lipids without irradiation also results in a lesser stimulation of adenylate cyclase by the beta-agonist. A possible mechanism of change in adenylate-cyclase functioning is discussed.