飞龙掌血水提物的扩血管作用及原理初探

The Vasodilative Effect of the Aqueous Extract of Asiatic Toddalia and Prelimary Studies of the Mechanism of Action

飞龙掌血的水提物飞龙一号(F01)给小鼠腹腔注射,其 LD_(50)=3.70g/kg。F01(80mg/kg)对麻醉 S.D.大鼠有明显降血压作用,伴有心率加快。该作用无快速耐受性,且不被 H_1及 H_2组胺受体、M 胆碱受体及β肾上腺素受体之阻断剂取消。对于离体 S.D.大鼠尾动脉螺旋条,F01(0.3至3mg/ml)可使由 KCl(60mmol/L)、NE(0.1μmol/L)或 AVP(0.01μmol/L)刺激而收缩的组织明显舒张。KCI(80mmol/L)增加血管平滑肌组织对钙的撮取,这可以通过测定组织中未被镧置换的低亲和力同位素^(45)Ca 的含量来确定。F01(0.06至4mg/ml)可显著降低这种钙摄取的增加。上述结果表明,F01具有直接扩张血管作用,此种作用与抑制钙内流有关。

The acute LD_(50) in mice was found to be 3.7g/kg for the aqueous extract of Asiatic todalia(F01)by i.p.F01(80mg/kg)had a significant hypotensive effect in anesthetized Sprague-Dawley(S.D.)rats,and an increase in heart rate followed it.This action did not exhibit tachyphylaxis and was not canceled by various receptor blockers,which included H_1-and H_2-histamin- ergic,M-cholinergie and β-adrenegic systems.In separated tail artery helical strips of S.D.rats F01(0.3～3mg/ml)was able to relax the constricted tissue stimulated by potassium chlorid(KCI 60mmol/L),noradrenaline(NE 9.1 μmol/L)or arginine vasopressin(AVP0.01μmol/L).KCl(80mmol/L)increased calcium uptake by the vascular tissue as determined by the measurement of the low-affinity lanthanum-resistant pool of calcium.Such increase in calcium uptake were significantly reduced by F01(0.06～4mg/ml).These results suggest that F01 have a direct vasodilative effect,which may be related to the inhibition of calcium influx.