摘要
目的：探讨Ｏ（４乙氧基丁基）小檗胺（ＥＢＢ）对离体蛙心的影响．方法：应用Ｓｔｒａｕｂ法制备离体蛙心；使用ＬＭＳ２Ａ记录仪经张力换能器描记心脏活动．结果：ＥＢＢ１－１００μｍｏｌ·Ｌ－１剂量依赖性增强蛙心收缩与舒张活动，但不影响心率；ＥＢＢ２５０－５００μｍｏｌ·Ｌ－１则引起心跳减慢，甚至停搏．ＥＢＢ的正性肌力作用不受西咪替丁１０μｍｏｌ·Ｌ－１和哌唑嗪１００μｍｏｌ·Ｌ－１影响；但可被维拉帕米０．０１μｍｏｌ·Ｌ－１所拮抗．ＥＢＢ能增强ＣａＣｌ２的正性肌力作用．与咖啡因和异丙肾上腺素比较，ＥＢＢ起效较慢，作用持续时间较长；但室温为（２１．０±０．５）℃时，与哇巴因比较却恰好相反．结论：ＥＢＢ的正性肌力作用至少部分是通过促进外Ｃａ２＋内流而非促进内Ｃａ２＋释放所致．
AIM: To study the effects of O-(4-ethoxylbutyl)-berbamine(EBB) on isolated frog heart. METHODS: The isolated frog hearts were prepared with Straub's method; heart contractions were recorded using LMS-2A recorder by tonotransducer. RESULTS: EBB 1-100 mu mol . L-1 caused concentration-dependent increase in systolic and diastolic activities, but did not alter the heart rate. EBB 250 - 500 mu mol . L-1 slowed the heart beats and caused ventricular asystole. Cimetidine 10 mu mol . L-1 or prazosin 100 mu mol . L-1 did not inhibit the positive inotropic action of EBB. Whereas verapamil 0.01 mu mol . L-1 antagonized the positive inotropic action of EBB. EBB enhanced positive inotropic action of CaCl2. The action of EBB was slower but longer than caffeine or isoproterenol. At room temperature (21.0 +/- 0.5) degrees C, however, the onset of oubain was slower, but the duration of its peak action was longer, than EBB. CONCLUSION: The positive inotropic action of EBB was, at least partially, via promoting the inward current of [Ca2+](o), rather than increasing the intracellular Ca2+ release.
出处
《中国药理学报》
CSCD
1998年第5期497-500,共4页
Acta Pharmacologica Sinica
关键词
小檗胺
西咪替丁
心肌收缩
berbamine
cimetidine
prazosin
ouabain
verapamil
isoproterenol
caffeine
calcium chloride
Bay K 8644
myocardial contraction
