论文部分内容阅读
用离体家兔和狗动脉环,探讨EI扩张血管的机理。EI对TA,MA,CA和CBA的静息张力均有一定的降低作用;EI不同于Phen,而与Ver,Pap相似,以非竞争性拮抗NE收缩TA环的作用;EI能明显减弱NE收缩TA环作用中Ca~(++)内流依赖性部分,而对NE所致快速收缩反应无明显影响;EI能够降低高K~+所致TA,MA和CA,5-HT所致CBA的收缩反应。上述结果提示:EI具有抑制血管平滑肌细胞外Ca~(++)内流作用,这可能是EI扩张血管的主要机理。
The isolated rabbit and dog arterial rings were used to investigate the mechanism of EI dilatation. EI had a depressive effect on the resting tension of TA, MA, CA and CBA; EI was different from Phen, but similar to Ver and Pap, it antagonized the effect of TA ring contraction by non-competitive NE; EI significantly attenuated NE contraction. The effect of TA ring on the Ca~(++) influx-dependent part has no obvious effect on the rapid contraction response induced by NE; EI can reduce the high K~+ induced TA,MA,CA,5-HT-induced CBA Contraction response. These results suggest that EI inhibits the extracellular Ca~(++) influx of vascular smooth muscle cells, which may be the main mechanism of EI dilation of blood vessels.