目的：比较钩藤中提取的异钩藤碱、钩藤碱、钩藤总碱及非生物碱部分的降压作用。方法：大鼠麻醉后经颈总动脉插管记录外周血压和经股静脉微量输注实验用药。结果：实验表明钩藤中4种成分的降压强度为异钩藤碱（42.0%）>钩藤碱（32.1%）>钩藤总碱（21.3%）>钩藤非生物碱（12.4%）。结论：提示钩藤中主要降压成分为异钩藤碱和钩藤碱。

Hypotensive effects of rhynchophylline, isorhynchophylline, total alkaloid andnon alkaloid fraction isolated from Uncaria rhynchophylla（Miq）Jacks. were compared Change in peripheral blood pressure was recorded by inserting a catheter into the right common carotid artery of anaethetized rat, while each of the four hypotensive constituents was injected individually into the femoral vein by a microinfusion pump Results of the findings showed that the four constituents in U rhynchophylla displayed different hypotensive potency in the order of isorhynchophylline [lowering of mean arterial pressure（MAP）by 420%] rhynchophylline（lowering of MAP by321%）total alkaloid（lowering of MAP by 213%）non alkaloid fraction（lowering of MAP by 124%）It was concluded that isorhynchophylline and rhynchophylline were the main hypotensive constituents in U rhynchophylla

国家中医药管理局“九·五”攻关基金（969030203）