van Herwaarden C L, Binkhorst R A, Fennis J F, van't Laar A
Br Heart J. 1979 Jan;41(1):99-105. doi: 10.1136/hrt.41.1.99.
A double-blind cross-over trial of the non-selective beta-blocker propranolol and the beta1-selective blocker metoprolol was carried out in 8 hypertensive patients. At the end of each 4-week period of treatment haemodynamic and respiratory indices and perceived exertion were studied during moderate exercise. Both beta-blockers resulted in reduced heart rate, cardiac output, and blood pressure, whereas the stroke volume increased. Total peripheral resistance did not change. During exercise the expiratory peak flow rate equally increased in every period. However, the peak flow rate at rest, as well as during exercise, was reduced by propranolol, while metoprolol had no such influence. Neither of the beta-blockers changed O2 consumption, CO2 production, tidal volume, or respiratory rate. Moreover, they did not influence perceived exertion. These results suggest that the arteriolar and bronchiolar beta2-receptors do not play a major role in the alteration of circulation and ventilation during exercise. As far as their practical use as antihypertensive agents is concerned, this study shows no advantage in the use of either of these beta-blockers.
在8名高血压患者中进行了非选择性β受体阻滞剂普萘洛尔和β1选择性阻滞剂美托洛尔的双盲交叉试验。在每4周治疗期结束时，研究了中度运动期间的血流动力学和呼吸指标以及主观用力感觉。两种β受体阻滞剂均导致心率、心输出量和血压降低，而每搏输出量增加。总外周阻力未改变。运动期间，每个时期的呼气峰值流速均同等增加。然而，普萘洛尔降低了静息时以及运动期间的峰值流速，而美托洛尔没有这种影响。两种β受体阻滞剂均未改变耗氧量、二氧化碳产生量、潮气量或呼吸频率。此外，它们不影响主观用力感觉。这些结果表明，小动脉和小支气管的β2受体在运动期间循环和通气的改变中不起主要作用。就它们作为抗高血压药物的实际应用而言，本研究表明使用这两种β受体阻滞剂中的任何一种均无优势。
