Novo S, Abrignani M G, Sapienza N D, Barbagallo M, Pinto A, Di Maria G U, Mistretta A, Strano A
Chair of Medical Pathophysiology, University of Catania, Italy.
Int Angiol. 1992 Apr-Jun;11(2):137-41.
We studied the structural and functional characteristics of the vascular bed at calf level in 46 middle aged hypertensive patients (20 males and 26 females) treated with different beta-blockers. After one week of placebo, the patients were divided into three groups: group 1 was treated with labetalol, an alpha-beta-blocker (200 mg t.t.d.); group 2 was treated with acebutolol, a cardioselective beta-blocker with intrinsic sympathomimetic activity (ISA) (200 mg t.t.d.); group 2 was treated with acebutolol, a cardioselective beta-blocker with intrinsic sympathomimetic activity (ISA) (200 mg t.t.d.); group 3 was treated with metoprolol, a cardioselective beta-blocker without ISA (100 mg t.t.d.). Before and after placebo, and after three months of active drug treatment, we measured blood pressure, and rest and peak flow at the calf level by strain gauge plethysmography. Basal and minimal vascular resistances were calculated as the ratio between mean blood pressure and rest or peak flow, respectively. A significant decrease in blood pressure was observed in each group. However, basal and minimal vascular resistances decreased only in the labetalol-treated group. These observations indicate that antihypertensive agents that have similar effects on blood pressure, may have different effects on minimal vascular resistance. Therefore, maximum vasodilation of arterioles improves, suggesting that long term treatment with labetalol, but not with other beta-blockers is able to induce a partial regression of vascular structural alterations in hypertensive patients.
我们研究了46例接受不同β受体阻滞剂治疗的中年高血压患者（20例男性和26例女性）小腿水平血管床的结构和功能特征。在服用安慰剂一周后，患者被分为三组：第一组用拉贝洛尔治疗，这是一种α-β受体阻滞剂（每日三次，每次200毫克）；第二组用醋丁洛尔治疗，这是一种具有内在拟交感活性（ISA）的心脏选择性β受体阻滞剂（每日三次，每次200毫克）；第三组用美托洛尔治疗，这是一种无ISA的心脏选择性β受体阻滞剂（每日三次，每次100毫克）。在服用安慰剂前后以及积极药物治疗三个月后，我们通过应变片体积描记法测量了血压以及小腿水平的静息和峰值血流量。基础血管阻力和最小血管阻力分别计算为平均血压与静息或峰值血流量的比值。每组血压均显著下降。然而，仅在拉贝洛尔治疗组中基础血管阻力和最小血管阻力下降。这些观察结果表明，对血压有相似作用的抗高血压药物，对最小血管阻力可能有不同作用。因此，提示小动脉最大程度的血管舒张改善，表明拉贝洛尔长期治疗而非其他β受体阻滞剂能够使高血压患者血管结构改变部分消退。
