Sánchez Torres G, Posadas C, Garcia Lara L, Suresh J, Serrano P
Arch Inst Cardiol Mex. 1978 May-Jun;48(3):549-61.
The effect of labetalol, a new alpha and beta adrenergic blocker, on blood pressure, heart rate, plasma renin activity (PRA), and urinary aldosterone excretion was assessed in 23 essential hypertensive patients, divided in 2 subgroups: 11 with normal electrocardiogram and 12 with left ventricular hypertrophy (LVH). In the first subgroup significant differences were found in the arithmethyc mean for sistolic blood pressure in sitting position (control: 166.1 +/- 17.2 mm of Hg treatment: 153.9 +/- 13.8, p less than or equal to 0.005) and in standing position (control: 165.3 +/- 17.3, treatment: 152.8 +/- 13.8, p less than or equal to 0.005) and for diastolic blood pressure (control: 102.7 +/- 12.6 to 89.9 +/- 10.1, p less than or equal to 0.001 and 103.2 +/- 11.8 to 91.2 +/- 10.8, p less than or equal to 0.001; in sitting and orthostatic positions, respectively.). No significant differences were found in the group with LVH. Heart rate decreased in the total population during treatment (- 6.0 +/- 7.5, p less than or equal to 0.05 and - 5.4 +/- 7.5 beats per minute, p less than or equal to 0.05 in sitting and orthostatic positions, respectively. PRA diminished in 12 of 15 cases studied (- 2.5 +/- 4.65 ng/ml/hr., p greater than 0.5). Correlation coefficient between decrements of diastolic blood pressure (sitting position) and ARP was 0.637. Aldosterone decreased in a non significant way during treatment. These data support the thesis of an important role of the adrenergic system in the pathogenesis of non complicated essential hypertension and, therefore, simultaneous alpha and beta receptor blockade in these cases has a better therapeutic effect. The good correlation between the decrements of ARP and blood pressure suggests an intervention of the inhibition of renin angiotensine system, brought about by the blocker property of labetalol, in the antihypertensive mechanism of the drug.
对23例原发性高血压患者评估了新型α及β肾上腺素能阻滞剂拉贝洛尔对血压、心率、血浆肾素活性（PRA）及尿醛固酮排泄的影响。这些患者分为2个亚组：11例心电图正常，12例有左心室肥厚（LVH）。在第一个亚组中，坐位收缩压算术平均值有显著差异（对照组：166.1±17.2 mmHg，治疗组：153.9±13.8，p≤0.005），站位时也有显著差异（对照组：165.3±17.3，治疗组：152.8±13.8，p≤0.005），舒张压也有显著差异（坐位时从对照组的102.7±12.6降至治疗组的89.9±10.1，p≤0.001；站位时从对照组的103.2±11.8降至治疗组的91.2±10.8，p≤0.001）。LVH组未发现显著差异。治疗期间总体人群心率下降（坐位时-6.0±7.5，p≤0.05；站位时-5.4±7.5次/分钟，p≤0.05）。15例研究对象中有12例PRA降低（-2.5±4.65 ng/ml/hr，p＞0.5）。坐位舒张压下降与ARP下降之间的相关系数为0.637。治疗期间醛固酮下降不显著。这些数据支持了肾上腺素能系统在非复杂性原发性高血压发病机制中起重要作用的论点，因此，在这些病例中同时阻断α和β受体有更好的治疗效果。ARP下降与血压下降之间的良好相关性提示，拉贝洛尔的阻滞剂特性所导致的肾素血管紧张素系统抑制参与了该药的降压机制。
