Isoproterenol-induced cardiac hypertrophy: modifications in characteristics of beta-adrenergic receptor, adenylate cyclase, and ventricular contraction.
Isoproterenol-induced cardiac hypertrophy: modifications in characteristics of beta-adrenergic receptor, adenylate cyclase, and ventricular contraction.
复制标题
异丙肾上腺素诱导的心脏肥大：β-肾上腺素受体、腺苷酸环化酶和心室收缩特性的改变。
作者：
J. Tse;J. Powell;C. Baste;R. Priest;J. Kuo
Several modifications in characteristics of the β- adrenergic receptor-adenylate cyclase system were observed in the cardiac hypertrophy of the rat produced by chronic isoproterenol treatment. These included 1) a decreased number of β- adrenergic receptors without changes in affinity when assayed by (-).[3H]dihydroalprenolol binding, 2) a decreased ability of 5′-guanylylimidodiphosphate to inhibit displacement by isoproterenol of the bound (-)-[3H]dihydroalprenolol, 3) a decreased sensitivity and magnitude of adenylate cyclase in heart homogenates to isoproterenol stimulation coupled with decreases in basal and NaF-stimulated enzyme activity, 4) a decreased responsiveness of the incubated heart minces to isoproterenol stimulation with respect to cAMP formation, and 5) a decreased contractile force development in ventricular strips in response to isoproterenol. All of the above alterations associated with the isoproterenol-induced cardiomegaly disappeared upon regressio n of hypertrophy. Light and electron...
