α-氯醛糖、乌拉坦和戊巴比妥钠对大鼠压力反射的影响

Effects of α chloralose, urethane and sodium pentobarbital on the baroreceptor reflex in rats

目的比较α－氯醛糖、乌拉坦和戊巴比妥钠对大鼠压力反射的抑制作用。方法采用事先插好动、静脉导管的自由活动大鼠，在静脉注射这３种麻醉药前后分别通过静脉注射盐酸去氧肾上腺素测定压力反射敏感性。结果α－氯醛糖和戊巴比妥轻度降低血压，乌拉坦对血压只有一过性降低作用，它们对心率均无显著影响。乌拉坦和戊巴比妥钠对压力反射均有显著抑制作用，抑制强度相当；而α－氯醛糖对压力反射只有短暂的轻度抑制，在给药后３０ｍｉｎ时压力反射功能已基本恢复。在给药后３０ｍｉｎ，α－氯醛糖组的压力反射敏感性显著高于戊巴比妥钠组和乌拉坦组。

AIM To assess the attenuation of the baroreceptor reflex by α chloralose, urethane and sodium pentobarbital. METHODS In chronically instrumented conscious rats, the baroreflex sensitivity(BRS) was determined by intravenous injection of phenylephrine before and after intravenous administration of these three anesthetic agents. RESULTS α chloralose and sodium pentobarbital slightly decreased blood pressure, while urethane transiently decreased blood pressure. None of them significantly changed heart rate. To the same extent, urethane and sodium pentobarbital significantly depressed baroreceptor reflex. α chloralose only transiently depressed baroreceptor reflex, and the BRS almost attained to the baseline thirty minutes after administration of it. CONCLUSION Attenuation of the baroreceptor reflex by α chloralose is less than urethane and pentobarbital.