Svensson A, Gudbrandsson T, Sivertsson R, Hansson L
Br J Clin Pharmacol. 1982;13(Suppl 2):259S-267S. doi: 10.1111/j.1365-2125.1982.tb01923.x.
1 In a double-blind study, 36 patients with essential hypertension were randomly allocated to treatment with either metoprolol, 100--300 mg/day, or pindolol, 5--15 mg/day for 6 months. Haemodynamic investigations were made on three separate occasions. Blood flow in the calves and in the forearm was determined by venous occlusion plethysmography after 6 weeks of placebo, after 6 weeks and again after 6 months of active therapy. 2 Both drugs reduced blood pressure significantly, by 17.1/11.8 mm Hg with metoprolol and 21.9/10.9 mm Hg with pindolol after 6 weeks (P less than 0.005). No further changes were seen after 6 months. 3 Heart rate after 6 weeks was significantly reduced by metoprolol (10.7 +/- 2.4 beats/min, P less than 0.001) but not by pindolol (4.4 +/- 2.3 beats/min, NS). After 6 months a significant reduction was seen also in the pindolol group (5.2 +/- 2.1 beats/min, P less than 0.05). 4 The vascular resistance in the calves at rest was reduced by pindolol (P less than 0.05), whereas resistance tended to increase with metoprolol. 5 Resting vascular resistance in the forearm after 6 months was significantly reduced in the metoprolol group (P less than 0.001) as well as in the pindolol group (P less than 0.02). The increase in forearm vascular resistance seen during leg exercise was not influenced by either drug. 6 Vascular resistance at maximal vasodilatation was unchanged in the calves, but a significant reduction (-17.4 +/- 5.7%, P less than 0.01) in the forearm vascular bed was seen after 6 months of pindolol. No change was observed with metoprolol. 7 It is concluded that pindolol reduces elevated blood pressure partly through peripheral vascular mechanism. Metoprolol, on the other hand, probably acts mainly via central cardiac mechanisms.
在一项双盲研究中，36例原发性高血压患者被随机分为两组，分别接受美托洛尔（100 - 300毫克/天）或吲哚洛尔（5 - 15毫克/天）治疗，为期6个月。在三个不同时间点进行了血流动力学研究。在安慰剂治疗6周后、积极治疗6周后以及6个月后，通过静脉阻塞体积描记法测定小腿和前臂的血流量。
两种药物均显著降低血压，6周后美托洛尔使血压降低17.1/11.8毫米汞柱，吲哚洛尔使血压降低21.9/10.9毫米汞柱（P < 0.005）。6个月后未见进一步变化。
6周后美托洛尔使心率显著降低（10.7 ± 2.4次/分钟，P < 0.001），而吲哚洛尔未使心率降低（4.4 ± 2.3次/分钟，无统计学意义）。6个月后，吲哚洛尔组心率也显著降低（5.2 ± 2.1次/分钟，P < 0.05）。
吲哚洛尔降低了静息状态下小腿的血管阻力（P < 0.05），而美托洛尔使血管阻力有增加趋势。
6个月后，美托洛尔组和吲哚洛尔组前臂的静息血管阻力均显著降低（美托洛尔组P < 0.001，吲哚洛尔组P < 0.02）。腿部运动期间前臂血管阻力的增加不受任何一种药物的影响。
小腿在最大血管舒张时的血管阻力未改变，但吲哚洛尔治疗6个月后前臂血管床显著降低（-17.4 ± 5.7%，P < 0.01）。美托洛尔未见变化。
结论是，吲哚洛尔部分通过外周血管机制降低升高的血压。另一方面，美托洛尔可能主要通过中枢心脏机制起作用。
