淫羊藿甙对血管平滑肌的作用

EFFECTS OF EPIMEDIUM ICARIINE ON RABBIT AND DOG VASCULAR SMOOTH MUSCLE

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。

EI can decrease the resting tension of blood vessel ring. The effect of EI,Ver, Pap, & Phen on NE dose-response curves was studied in rabbit TA. While Phen competitively antagonized NE, EI, & Ver,Pap also antagonized NE, but in a non-competitive manner. In Ca^(2+)-free Kreb-Henseleit solution. NE caused initial fast response which could not be caused by EI, while with Ca^(2+)added, Ca^(2+)-dependant response was markedly reduced by EI. Moreover, EI inhibited contraction evoked by K^+in rings of TA,MA and CA and inhibited the contraction of CBA ring induced by 5-HT,too. These findings suggest that El-induced vasodilation results from its inhibiting against receptoroperated and potential-dependant calcium influx.