粉防己碱对犬多种血管平滑肌的作用

观察了粉防己碱（Ｔｅｔ）对犬离体冠状动脉，脑基底动脉和肠系膜动脉平滑肌的作用。Ｔｅｔ３０μｍｏｌ·Ｌ－１对ＫＣｌ２０及６０ｍｍｏｌ·Ｌ－１去极化犬冠状动脉呈非内皮依赖性松弛。给格列本脱后，Ｔｅｔ仍可使冠状动脉松弛７４．５％．Ｔｅｔ可使ＫＣｌ所致冠状劝脉收缩的量效曲线右移，最大反应降低，ｐＤ２为４．４其－ｌｇＥＣ５０与其松弛苯福林引起的大肠系膜劝脉收缩的－ｌｇＥＣ５０相近，均为４．１Ｔｅｔ对ＫＣｌ所致犬基底动脉的收缩有明显松弛作风

Effects of tetrandrine on canine various vascmar smooth muscles

The effects of tetrandrine(Tet)on iso-lated canine vessels were investigated. In theaunine left cir-cumflex coronary artery rings with or withoutendothelium, Tet 30 μmol·L-1 caused significantrelaxing response of pre-constricted with 20 mmol·L -1KCl in endothelium-indepentent fashion Tet pro-duced a relaxation by 50% on KCl 60mmol ·L-1 in-duced contraction of coronary artery.In the presence ofglibenclamide,the relaxing response to Tet in KCl-Con-tracted coronary artery was not significantly differentfrom the control.i.e.,it still caused relaxation by 74.5%.Tet non-parallelly shifted the dose-response curves forKCl to the right with a lower maximal response,thepD2 value was shown to be 4.4,Tet 10 μmol·L-1 cau-sed significant relaxing response in 45 mmol·L-1 KCl-induced contraction in canine basal artery ring.Tet in-dueed a marked concentration-dependent reduction incontractile response to added phenylephrine in mesentericartery or KCl in coronary artery. Both-lg EC50 were 4.1.