Brodde O E, Schüler S, Kretsch R, Brinkmann M, Borst H G, Hetzer R, Reidemeister J C, Warnecke H, Zerkowski H R
J Cardiovasc Pharmacol. 1986 Nov-Dec;8(6):1235-42. doi: 10.1097/00005344-198611000-00021.
We evaluated the amount of beta 1- and beta 2-adrenoceptors in human right and left atrium as well as in right and left ventricular wall obtained from heart transplant recipients who suffered from end-stage congestive cardiomyopathy. The total number of myocardial beta-adrenoceptors was assessed with the nonsubtype selective beta-adrenoceptor radioligand (-)[125I]iodocyanopindolol (ICYP); concomitantly, the number of beta 1-adrenoceptors was determined with the selective beta 1-adrenoceptor radioligand (-)[3H]bisoprolol. The number of beta 2-adrenoceptors was calculated by subtracting (-)[3H]bisoprolol binding sites from ICYP binding sites. With this technique, a beta 1/beta 2-ratio of approximately 65/35% for both atria and of approximately 75/25% for both ventricles was found. Identical results were obtained when the beta 1/beta 2-ratio was calculated indirectly by nonlinear regression analysis of competition curves of the selective beta 1-adrenoceptor antagonist bisoprolol and the selective beta 2-adrenoceptor antagonist ICI 118,551 with ICYP binding. In addition, on atria and on ventricles, adenylate cyclase was activated by norepinephrine (presumably by beta 1- and beta 2-adrenoceptor stimulation) and by procaterol (by beta 2-adrenoceptor stimulation). It is concluded that in the human heart functional beta 1- and beta 2-adrenoceptors coexist on both atria and both ventricles. In end-stage congestive cardiomyopathy, there appears to be a selective down-regulation of cardiac beta 1-adrenoceptors, whereas beta 2-adrenoceptors are obviously not affected. This may explain the beneficial effects of beta 2-adrenoceptor agonists in severe heart failure.
我们评估了患有终末期充血性心肌病的心脏移植受者的右心房和左心房以及右心室壁和左心室壁中β1 - 和β2 - 肾上腺素能受体的数量。用非亚型选择性β - 肾上腺素能受体放射性配体（-）[125I]碘氰吲哚洛尔（ICYP）评估心肌β - 肾上腺素能受体的总数；同时，用选择性β1 - 肾上腺素能受体放射性配体（-）[3H]比索洛尔测定β1 - 肾上腺素能受体的数量。β2 - 肾上腺素能受体的数量通过从ICYP结合位点减去（-）[3H]比索洛尔结合位点来计算。用这种技术，发现两个心房的β1/β2比例约为65/35%，两个心室的β1/β2比例约为75/25%。当通过选择性β1 - 肾上腺素能受体拮抗剂比索洛尔和选择性β2 - 肾上腺素能受体拮抗剂ICI 118,551与ICYP结合的竞争曲线的非线性回归分析间接计算β1/β2比例时，得到了相同的结果。此外，在心房和心室上，去甲肾上腺素（可能通过刺激β1 - 和β2 - 肾上腺素能受体）和丙卡特罗（通过刺激β2 - 肾上腺素能受体）激活腺苷酸环化酶。结论是，在人类心脏中，功能性β1 - 和β2 - 肾上腺素能受体在心房和心室中均共存。在终末期充血性心肌病中，心脏β1 - 肾上腺素能受体似乎存在选择性下调，而β2 - 肾上腺素能受体显然未受影响。这可能解释了β2 - 肾上腺素能受体激动剂在严重心力衰竭中的有益作用。
