三种麻醉剂对蟾蜍离体心脏生理特性的影响

本实验采用蟾蜍离体心脏灌流方法分别观察了氨基甲酸乙酯、戊巴比妥钠、水合氯醛三种麻醉剂对心脏收缩性和百动节律性的影响．结果：对心率，三种麻醉剂均有抑制作用，其中氨基甲酸乙酯抑制作用最大，抑制率为27．1％；水合氯醛抑制作用次之，抑制率为18．9％；戊巴比妥钠抑制作用最小，抑制率为5．6％．去除麻醉剂后，氨基甲酸乙酯组能立即恢复正常，戊巴比妥钠组和水合氯醛组心率均不能立即恢复到正常水平．对心脏收缩力，三者均有较强的抑制作用。氨基甲酸乙酯对收缩力抑制率为26．0％，戊巴比妥纳为23．0％，水合氯醛为12．0％，去除麻醉剂后。氨基甲酸乙酯组和水合氯醛组较易恢复到正常水平，戊巴比妥钠组不易恢复。

EFFECTS OF THREE ANAESTHETICS ON THE PHYSIOLOGICAL CHERISTERISTICS OF ISOLATED HEART OF TOAD

The experiment studied the effects of three anesthetics(urethane,pentobarbital,chloral hydrate)on the heart rate and cardiac contractility of isolated heart of toad.The results showed that each of them inhibited heart rate and cardiac contractility of isolated heart.Urethane had the strongest inhibitory effect on heart rate,the inhibitory rate was (27.1%.)However,pentobarbital sodium had the least inhibitory effect on the heart rate,and the inhibitory rate was (5.6%.)After anesthetics were removed,the recovery of the heart rate of toad anaesthetized by urethane was quick,but the recovery of heart rate in the groups of pentobarbital or chloral hydrate was very slow.Moreover,urethane had the strongest inhibitory effect on cardiac contractility,the inhibitory rate was 26.0%.Chloral hydrate had the least inhibitory effect on cardiac contractility and the inhibitory rate was 12.0%.After the anesthetics was removed,the cardiac contractility of toads anaesthetized by urethane or by chloral hydrate was resumed efficiently,but that of toads anaesthetized by pentobarbital sodium was recovered slowly.