山莨菪碱对离体血管和心房细胞内、外钙影响的研究

STUDIES ON EFFECTS OF ANISODAMINE TO INTRA-AND EXTRACELLULAR Ca^(2+) IN ISOLATED RABBIT AORTA AND GUINEA PIG ATRIA

山莨菪碱(Ani)能拮抗PE和高K^+所致兔主动脉条收缩,IC_(50)分别为120和86μmol/L,两者比值PE/K^+(IC_(50))=1.39,小于Ver;对5-HT两种收缩成分均有抑制作用;亦能抑制豚鼠左房“静息后增强”和“阶梯现象”;对CaCl_2收缩兔主动脉和豚鼠左房具有非竞争性抑制作用。结果提示,山莨菪碱对细胞外钙经PDC和ROC所致收缩以及由细胞内钙释放诱导的收缩均有拮抗作用。

In the isolated rabbit aorta, like verapamil ( Ver ) anisodamine ( Ani ) might inhibit the contraction induced by phenylephrine ( PE ) and high K+ with IC50 value of 120 and 86 μ mol/L, respectively. PE/K+ ratio of IC50 was 1.4 which was less than that of Ver. It showed that although PDC may be more sensitive to Ani than ROC, the difference in sensitivity of Ani on 2 calcium chan- nel are less marked than that of some calcium antagonists. Ani had inhibitory effects on 2 contractile components of serotonin (5-HT ) . Ani and Ver could obviously inhibit post-resting potentiatipn and staircase phenomenon in guinea pig atria. Ani also might inhibit the contraction induced by calcium and shift concentration-response nonparallelly to right on both tissues above. The results suggest that Ani possesses nonspecific calcium antagonistic effect and reduces the tension by affecting PDC and ROC to decrease extracellular calcium influx and inhibiting intracellular calcium release.