莲心碱对几种平滑肌作用的研究

Research on the action of liensinine on several smooth muscles

莲心碱（Ｌｉｅ）抑制去氧肾上腺素（ＰＥ），５－羟色胺（５－ＨＴ），组胺（Ｈｉｓ）和高Ｋ＋引起的兔主动脉环收缩，对ＰＥ引起的收缩，其抑制作用更为明显；也抑制ＰＥ所致兔尿道平滑肌的收缩。在兔主动脉环和大鼠肛尾肌标本，Ｌｉｅ使甲氧胺（Ｍｅｔ）及ＰＥ的量效曲线平行右移，最大反应不压低，ＰＡ２值分别为６．８和６．６。Ｌｉｅ还明显抑制去甲肾上腺素（ＮＥ）所致的内钙释放，而对ＮＥ所致外钙内流影响较小。提示：Ｌｉｅ具有阻断肾上腺素α１受体和抑制细胞内钙释放作用。

The contraction of the isolated rabbit aortic rings induced by phenylephrine(10μmol·L-1),serotonin(10μmol ·L-1),histamine(10μmol·L-1) and KCl (40 mmol·L-1) could be ralaxed by liensimine(100μmol·L-1). The inhibition to the contraction caused by phenylephrine was most significant. Liensinine also inhibited the contraction of the isolated rabbit urethra rings induced by phenlylephrine.Liensinine shifted methoxamine and Phenylephrine dose-response curve rightward parallelly without decreasing the maximal response in isolated aortic rings and rat anococcygeus muscles. The pA2 values of liensinine were 6. 8 and 6. 6,respectively.Liensinine(30μmol·L-1)obviously inhibited the intracellular Ca2+ release,but only slightly decreased the extracellular Ca2+ influx induced by Norepinephrine. The results suggest that liensinine's smooth muscle realaxing action may be related to the competitive α-adrenoceptor blocking action and the inhibition of intracellular Ca2+release.