异钩藤碱对麻醉兔心脏传导功能的影响

Effects of isorhynchophylline on heart conduction function in anesthetized rabbits

采用心房起搏及希氏束电图方法观察了异钩藤碱（Ｉｓｏｒｈｙ）对麻醉兔心脏传导功能的影。一次ｉｖＩｓｏｒｈｙ８ｍｇ·ｋｇ－１，５ｍｉｎ产生最大抑制效应，３０－１２０ｍｉｎ作用消失．恒速ｉｖＩｓｏｒｈｙ０－１６ｍｇ·ｋｇ－１呈剂量依赖性减慢心率，延长窦房结恢复时间，窦房传导时间及心房－希氏束间期，希氏束－心室间期，心电图的Ｐ－Ｒ间期．其中对房室传导抑制显著，Ｉｓｏｒｈｙ对心脏传导功能的影响可部分被异丙肾上腺素对抗，而不受阿托品影响．

Isorhynchophylline(Isorhy)is one ofthe major alkaloids extracted from Chinese traditionalmedicine,Uncariaria rhynchophylla(Miq.Jackson Byusing atrial pacing and recording His bundleelectrograms,effects of Isorhy on heart conductionhnction in anesthetized rabbits were observed.Themaximal inhibitory response occurred in 5 min afterIsorhy 8 mg·kg-1 iv and disappeared during 30-120min.Isorhy, infusion 0-16 mg·kg-1 at a constantrate,dosc-dependcntly decreased heart rate pro-longcdsinus node recovery time, and P-R,A-H,H-Vintervals.The depression of Isorhy on heart rate andatrioventricular conduction are marked.Isoprenalinepartially antagonized these inhibitory effects of lsorhy.but atropine could not do.