Elnatan J, Molenaar P, Rosenfeldt F L, Summers R J
Department of Pharmacology, University of Melbourne, Parkville Vic., Australia.
J Mol Cell Cardiol. 1994 Mar;26(3):313-23. doi: 10.1006/jmcc.1994.1040.
The density and distribution of beta 1- and beta 2-adrenoceptors in the atrioventricular conducting system and interatrial and interventricular septa from human hearts with idiopathic dilated cardiomyopathy and ischemic heart disease was determined by quantitative autoradiography using (-)[125I]cyanopindolol and the selective beta 1-adrenoceptor antagonist CGP 20712A and the selective beta 2-adrenoceptor antagonist ICI 118,551. Both beta 1- and beta 2-adrenoceptors were present in the atrioventricular node, bundle of His, interatrial and interventricular septa. No differences in the density or proportions of beta 1- and beta 2-adrenoceptors in the atrioventricular node, bundle of His, interatrial septum and interventricular septum were observed between hearts with idiopathic dilated cardiomyopathy or ischemic heart disease (P > 0.05) so further analysis did not distinguish between the two aetiologies. The density of beta 1-adrenoceptors was lower in the bundle of His (5.0 +/- 1.7 fmol/mg protein) than in the atrioventricular node (22.2 +/- 5.7 fmol/mg protein, P < 0.05), the interatrial septum (29.6 +/- 4.5 fmol/mg protein, P < 0.001) and interventricular septum (24.9 +/- 5.2 fmol/mg protein, P < 0.005, n = 8 for all values). The atrioventricular node, interatrial and interventricular septa had similar densities of beta 1-adrenoceptors (P = 0.60, ANOVA). The distribution of beta 2-adrenoceptors in the atrioventricular node (21.5 +/- 4.1 fmol/mg protein), bundle of His (12.9 +/- 2.6 fmol/mg protein) and atrial (16.7 +/- 2.3 fmol/mg protein) and septal myocardium (13.8 +/- 2.5 fmol/mg protein, n = 8 for all values) was uniform (P = 0.18, ANOVA). The percentage of beta 1- and beta 2-adrenoceptors in the atrioventricular node, bundle of His, interatrial and interventricular septa was uneven (P < 0.001, ANOVA). There was a higher proportion of beta 2-adrenoceptors in the bundle of His (72 +/- 6%) than in the atrioventricular node (51 +/- 3%, P < 0.01), interatrial septum (36 +/- 1%, P < 0.001) and interventricular septum (36 +/- 1%, P < 0.001).
采用（-）[¹²⁵I]氰吲哚洛尔以及选择性β₁肾上腺素能受体拮抗剂CGP 20712A和选择性β₂肾上腺素能受体拮抗剂ICI 118,551，通过定量放射自显影法测定特发性扩张型心肌病和缺血性心脏病患者心脏的房室传导系统以及房间隔和室间隔中β₁和β₂肾上腺素能受体的密度及分布。β₁和β₂肾上腺素能受体均存在于房室结、希氏束、房间隔和室间隔中。在特发性扩张型心肌病或缺血性心脏病患者的心脏中，未观察到房室结、希氏束、房间隔和室间隔中β₁和β₂肾上腺素能受体的密度或比例存在差异（P＞0.05），因此进一步分析未区分这两种病因。希氏束中β₁肾上腺素能受体的密度（5.0±1.7 fmol/mg蛋白）低于房室结（22.2±5.7 fmol/mg蛋白，P＜0.05）、房间隔（29.6±4.5 fmol/mg蛋白，P＜0.001）和室间隔（24.9±5.2 fmol/mg蛋白，P＜0.005，所有值n = 8）。房室结、房间隔和室间隔中β₁肾上腺素能受体的密度相似（P = 0.60，方差分析）。β₂肾上腺素能受体在房室结（21.5±4.1 fmol/mg蛋白）、希氏束（12.9±2.6 fmol/mg蛋白）以及心房（16.7±2.3 fmol/mg蛋白）和间隔心肌（13.8±2.5 fmol/mg蛋白，所有值n = 8）中的分布是均匀的（P = 0.18，方差分析）。房室结、希氏束、房间隔和室间隔中β₁和β₂肾上腺素能受体的百分比不均衡（P＜0.001，方差分析）。希氏束中β₂肾上腺素能受体的比例（72±6%）高于房室结（51±3%，P＜0.01）、房间隔（36±1%，P＜0.001）和室间隔（36±1%，P＜0.001）。
