染料木素对狗基底动脉环舒张作用及其机制的离体研究

目的：探讨血管张力变化对染料木素的脑血管保护作用及相关机制的比较。方法：（1）制备狗基底动脉血管环固定于恒温肌槽内，待平衡后，加入各种药物观察血管张力的变化。结果：（1）200μmol／L GST可浓度依赖性地压低氯化钾（KCl）量效曲线，使其明显右移，最大收缩反应和肌条对KCl的敏感性明显降低。（2）无Ca^2＋K—H液中。染料术素对去甲肾上腺素（NA）诱发产生第一时相收缩和CaCl2产生第二时相收缩均具有明显的抑制作用。（3）染料木素可使60mmol／L KCl预收缩基底动脉血管环产生明显的舒张作用，除内皮细胞或加入一氧化氮合酶抑制剂Nω—L-硝基精氨酸1×10^-4mol／L．甲烯兰1×10^-5mol／L．1×10^-5mol／L吲哚美辛或格列本脲1×10^-5mol／L温育后，染料木素对60mmol／L KCl预收缩动脉血管环产生的量效舒张作用无明显改变（P〉0．05）。结论：（1）染料木素对基底动脉血管舒张可能是直接作用于平滑肌而引起的，即抑制电压依赖性的钙通道。无Ca^2＋K—H液中，抑制NA从细胞内释放贮存的Ca^2＋。（2）染料木素对基底动脉血管的舒张作用与内皮细胞及其释放的一氧化氮无关。前列腺素类物质的合成和KATP通道亦无关。

Relaxant effect of genistein on canine basilar arteries in vitro and its mechanism

Objective：To compare the genistein-induced vasorelaxant effect and its correlated mechanisms using vascular tension change as the index. Methods：Canine basilar arterial rings were prepared and then mounted in the organ bath, after an equilibration peried, the changes treated with the drugs were observed. Results：GST caused the dese-response contractile curve of KCI in：K-H shift rightward,NA and CaCl2 in Ca^2＋ -free K-H solution in biphasic response and their sensitivies and the values of maximum contractions were decreased. （2）After incubation with inhibitor of nitric oxide synthase Nω-L-nitro-arginine （L-NNA）,methylene blue （MB）,indomethacin（INDO）,glibenclamide （GLM） and endothelium removal, gcnistein induced-relaxation had no change（P〉0.05）.Conclusion： （1）Genistein induces the vasorelaxant response mainly via inhibition of voltage-dependent calcium channel and Ca^2＋ release from intracellular stores induced by NA in Ca^2＋ -free K-H solution. （2）The vasorelaxant effect of genistein is probably endothelium-independent and not related to NO and prostaglandins and as well as KATP channel in isolated basilar arterial rings.