da Silva V J, da Silva S V, Salgado M C, Salgado H C
Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
Hypertension. 1994 Jan;23(1 Suppl):I68-72. doi: 10.1161/01.hyp.23.1_suppl.i68.
We investigated the acute and chronic effects of converting enzyme inhibitors (captopril or enalapril) and of angiotensin II receptor blockade (DuP 753) on rapid (30-minute) baroreceptor resetting elicited by a prompt and sustained hypertensive response provoked by aortic constriction. Pressure-nerve activity curves, pressure at 50% of maximal baroreceptor activity, baroreceptor gain (slope of the curve), and systolic threshold pressure for baroreceptor activation were determined as indexes of baroreceptor function. A slight fall in mean arterial pressure after acute treatment with the converting enzyme inhibitor or DuP 753 was accompanied by a partial leftward curve shift, which is associated with a partial threshold shift and increase in gain. A maintained hypertensive stimulus caused a partial rightward curve shift and partial (49% to 56%) threshold shift to hypertensive levels in both acutely treated and control rats. The hypertensive stimulus provoked a partial rightward curve shift and complete (88% to 94%) threshold shift to hypertensive levels in chronically treated rats. The effect of enalapril on baroreceptor function was unaltered by the bradykinin antagonist Hoe 140. These data demonstrate that chronic inhibition of converting enzyme or blockade of angiotensin II receptors facilitates rapid resetting of the baroreceptors to hypertensive levels caused by partial aortic constriction without a change in baroreceptor sensitivity.
我们研究了转换酶抑制剂（卡托普利或依那普利）以及血管紧张素II受体阻滞剂（DuP 753）对由主动脉缩窄引发的快速（30分钟）压力感受器重调定的急性和慢性影响，该快速压力感受器重调定由迅速且持续的高血压反应所引起。测定压力-神经活动曲线、最大压力感受器活动50%时的压力、压力感受器增益（曲线斜率）以及压力感受器激活的收缩阈压力，以此作为压力感受器功能的指标。用转换酶抑制剂或DuP 753进行急性治疗后，平均动脉压略有下降，同时伴有曲线部分向左移位，这与阈值部分移位及增益增加有关。在急性治疗的大鼠和对照大鼠中，持续的高血压刺激均导致曲线部分向右移位以及阈值部分（49%至56%）向高血压水平移位。在慢性治疗的大鼠中，高血压刺激引发曲线部分向右移位以及阈值完全（88%至94%）向高血压水平移位。缓激肽拮抗剂Hoe 140并未改变依那普利对压力感受器功能的影响。这些数据表明，慢性抑制转换酶或阻断血管紧张素II受体可促进压力感受器对部分主动脉缩窄所致高血压水平的快速重调定，而压力感受器敏感性并无变化。
