Brown M J, Sanders L
Department of Medicine, University of Cambridge, UK.
J Hum Hypertens. 1990 Jun;4 Suppl 2:55-8.
The beta 1- and beta 2-adrenoceptor agonist effects of dilevalol on human heart tissue were studied in vitro. The receptors were studied independently of one another through the use of selective antagonists. Human right atrial appendages were generally cut into four strips which were then set up in parallel in an organ bath system. All tissues were incubated either with 300 nM CGP 20712A to block beta 1-adrenoceptors, or with 50 nM ICI 118551, to block beta 2-adrenoceptors. Alpha-adrenoceptors and tissue uptake of catecholamines were blocked using 5 microM phenoxybenzamine. The atrial strips from one patient were then exposed either to vehicle or to cumulative additions of dilevalol, (+)- pindolol or salbutamol (10(-8) to 10(-5) M) and the resulting force of contraction was expressed as a percentage of the inotropic response obtained with a saturating dose of (-)-isoprenaline. The beta-antagonist effects of the three substances were also studied, by running a dose-response curve to noradrenaline or adrenaline as appropriate following the addition of the substance of interest. Neither dilevalol nor (+)-pindolol had any intrinsic sympathomimetic activity at the atrial beta 1- or beta 2-adrenoceptors. Both dilevalol and (+)-pindolol caused marked antagonism of the atrial beta-adrenoceptors. They caused similar blockade of the beta 2-adrenoceptors but not of the beta 1-adrenoceptors.
在体外研究了双醋洛尔对人心脏组织的β1和β2肾上腺素能受体激动作用。通过使用选择性拮抗剂对受体进行独立研究。人右心耳通常切成四条，然后在器官浴系统中平行设置。所有组织均用300 nM CGP 20712A孵育以阻断β1肾上腺素能受体，或用50 nM ICI 118551孵育以阻断β2肾上腺素能受体。使用5 μM酚苄明阻断α肾上腺素能受体和儿茶酚胺的组织摄取。然后将一名患者的心房条带暴露于溶剂或双醋洛尔、(+)-吲哚洛尔或沙丁胺醇（10(-8)至10(-5) M）的累积添加物中，收缩力表示为用饱和剂量的(-)-异丙肾上腺素获得的变力反应的百分比。在加入感兴趣的物质后，通过对去甲肾上腺素或肾上腺素进行剂量反应曲线研究了这三种物质的β拮抗剂作用。双醋洛尔和(+)-吲哚洛尔在心房β1或β2肾上腺素能受体上均无任何内在拟交感活性。双醋洛尔和(+)-吲哚洛尔均引起心房β肾上腺素能受体的明显拮抗作用。它们对β2肾上腺素能受体的阻断作用相似，但对β1肾上腺素能受体的阻断作用不同。
