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

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.