粉防己碱，钩藤碱和维拉帕米对兔主动脉平滑肌细胞内外钙转运的作用

粉防己碱和钩藤碱对由高钾和去甲肾上腺素引起的兔主动脉条收缩的抑制作用没有维拉帕米强。粉防己碱，钩藤碱和维拉帕米在由去甲肾上腺素和５－羟色胺引起的两相收缩中，抑制Ⅰ相收缩的ＩＣ５０小于抑制Ⅱ相收缩的ＩＣ５０．粉防己碱，钩藤碱抑制由去甲肾上腺素引起的Ⅰ相收缩的ＩＣ５０分别是抑制高钾所致收缩的１／１２．８和１／６．但维拉帕米没有表现此种关系，三种药物均不能对抗卡西霉素引起的收缩。粉防己碱和钩藤碱能增强咖啡因所致收缩，但维拉帕米抑制之，这些结果表明粉防己碱和钧藤碱为细胞内钙动员抑制剂，而且它们的作用点不同于维拉帕米。

Effects of tetrandrine, rhynchophylline and verapamilon transference of intracellular and extracellularcalcium in rabbit aorta smooth muscle 1

The inhibitory effects of tetrandrine (Tet) andrhynchophylline (Rhy) on the high concentration of K and norepinephrine (NE)-induced rabbit aortic strip contrac-tions were less marked than those of verapamil (Ver). TheIC50 values of the three drugs for the lst phase of contrac-tions were less than those for the Znd phase of contractionsinduced by NE and serotonin. The IC50 values of Tet andRhy for the lst phase of contractions by NE were 1 / 12.8and 1 /6 of those of high concentration of K inducingcontractions, respectively. But Ver did not display thiseffect. Tet, Rhy and Ver failed to antagonize the contractioninduced by calcimycin. Tet and Rhy facilitated the contrac-tion evoked by caffcine, but Ver reduced it. These resultssuggest that Tet and Rhy are the intracellular Ca2 mobil-izing inhibitors, and their target sites are different fromthose of Ver.