Kumagai H, Suzuki H, Matsumura Y, Ryuzaki M, Saruta T
Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.
J Hypertens. 1992 Dec;10(12):1485-91. doi: 10.1097/00004872-199210120-00008.
To test the hypothesis that an angiotensin I converting enzyme inhibitor and a calcium channel blocker have different effects on the arterial baroreflex in renal hypertension.
We examined the baroreflex control of renal sympathetic nerve activity and heart rate before and after blood pressure was reduced by a similar magnitude (11 +/- 1 mmHg) with intravenous captopril or nicardipine in two-kidney, one clip hypertensive (mean arterial pressure 92 +/- 2 mmHg, n = 12) and normotensive rabbits (mean arterial pressure 75 +/- 1 mmHg, n = 9) in the conscious state. Data obtained during activation and deactivation of baroreceptors were analysed with logistic function curves, and the maximum slope of the curve was taken as the sensitivity of the baroreflex.
The maximum slopes of the curves relating mean arterial pressure to renal sympathetic nerve activity and to the heart rate in hypertensive rabbits were significantly smaller than the maximum slopes in normotensive rabbits. In renal hypertensive rabbits, the maximum slope of the mean arterial pressure-renal sympathetic nerve activity curve was increased with captopril compared with that with vehicle. In contrast, the maximum slope of the mean arterial pressure-heart rate curve was increased with nicardipine compared with that with vehicle.
Our data indicating that the baroreflex control of renal sympathetic nerve activity was improved by captopril and that baroreflex control of the heart rate was potentiated by nicardipine suggest that these classes of antihypertensive agents had differential effects in conscious hypertensive rabbits.
验证血管紧张素I转换酶抑制剂和钙通道阻滞剂对肾性高血压动脉压力反射有不同影响这一假说。
我们在清醒状态下，用静脉注射卡托普利或尼卡地平使两肾一夹型高血压兔（平均动脉压92±2 mmHg，n = 12）和正常血压兔（平均动脉压75±1 mmHg，n = 9）的血压下降相似幅度（11±1 mmHg）前后，检测肾交感神经活动和心率的压力反射控制。用逻辑函数曲线分析压力感受器激活和失活期间获得的数据，曲线的最大斜率作为压力反射的敏感性。
高血压兔中，平均动脉压与肾交感神经活动及心率关系曲线的最大斜率显著小于正常血压兔。在肾性高血压兔中，与使用赋形剂相比，卡托普利使平均动脉压-肾交感神经活动曲线的最大斜率增加。相反，与使用赋形剂相比，尼卡地平使平均动脉压-心率曲线的最大斜率增加。
我们的数据表明，卡托普利改善了对肾交感神经活动的压力反射控制，尼卡地平增强了对心率的压力反射控制，提示这些类别的抗高血压药物在清醒高血压兔中有不同作用。
