Nyberg G, Berglund G
Acta Med Scand Suppl. 1982;665:93-101. doi: 10.1111/j.0954-6820.1982.tb00415.x.
Eleven patients with essential hypertension participated in a double-blind cross-over comparison of labetalol (L) and propranolol (P). Each drug was given for 5--8 weeks. The dose reducing the supine diastolic blood pressure when given b.d. to or below 90 mm Hg was titrated out. At the end of each period, isometric exercise (sustained handgrip) and calf plethysmography were performed. L (mean daily dose 636 mg) was slightly more effective in lowering supine and standing blood pressure than P (mean dose 276 mg). There was no significant difference between the drugs in their effect on the blood-pressure response to handgrip. However, compared with no treatment, L attenuated the blood-pressure rise at near-maximal handgrip; this has not been reported with other beta-blockers. Resting vascular resistance and basal vascular tone were significantly lower (20%, p less than 0.05) during treatment with labetalol than when the patients were taking propranolol. - The differences may be explained by the alpha-receptorblocking action of labetalol.
11名原发性高血压患者参与了拉贝洛尔（L）和普萘洛尔（P）的双盲交叉对照试验。每种药物给药5 - 8周。每日两次给药使仰卧位舒张压降至或低于90 mmHg时的剂量进行滴定调整。在每个阶段结束时，进行等长运动（持续握力）和小腿体积描记法。拉贝洛尔（平均日剂量636 mg）在降低仰卧位和站立位血压方面比普萘洛尔（平均剂量276 mg）稍有效。两种药物对手握力时血压反应的影响无显著差异。然而，与未治疗相比，拉贝洛尔在接近最大握力时减弱了血压升高；其他β受体阻滞剂未见此报道。与服用普萘洛尔时相比，服用拉贝洛尔治疗期间静息血管阻力和基础血管张力显著降低（20%，p<0.05）。这些差异可能由拉贝洛尔的α受体阻断作用来解释。
