钾通道拮抗剂IBTX对大鼠脑缺血再灌注损伤的保护作用及其机制的试验研究

The protective effect and its possible mechanism of potassium channel blocker IBTX after cerebral ischemia-reperfusion in rats.

目的:探讨大鼠脑缺血再灌注损伤后,海马CAl区锥体细胞caspaso-3表达及细胞凋亡的变化及使用钾通道拮抗剂IBTX(ibetiotoxin)的保护作用及其保护机制。方法:通过腹腔注射硝普钠加双侧颈总动脉夹闭建立大鼠全脑缺血一再灌模型,侧脑室注射IBTX,免疫组化法测caspase-3表达情况,TUNEL法检测细胞凋亡。结果:大鼠全脑缺血-再灌注24小时后,海马CAl区锥体细胞caspase-3阳性表达,TUNEL法检测有细胞凋亡,在用药IBTX组,caspase-3阳性表达减少,TUNEI法检测细胞凋亡亦有明显降低。结论:大鼠全脑缺血-再灌注24小时后海马CAl区锥体细胞出现细胞凋亡,使用钾通道拮抗剂IBTX可减少细胞凋亡的发生,从而发挥保护作用。

objective: To investigate the protective eitect oi potassium channel blocker IBTX and its possible protective mechanism which have sore relations to apoptosis in hippocampal CAl region after cerchral ischemia/reperfusion in rats. Methods: Globe ischemiawas made in SD rats. And those in therapeutic group were given IBTX by intraventricular in jec-tion. Immunohistochemistry staining was made to detect the expression of caspase-3, and TUNEl method was used to detect apoptosis. Results: After a day of cerebral ischemia/reperfusion in rats, the positive expression of caspase-3 and TUNEL was both found in hippocampai CAl region, ttowever, the positive expression of caspase-3 was decreased in IBTX group, and the apoptosis detected by TUNEL was also decreased markedly. Conclusion: These findings suggest that apoptosis appear in the hippocampal CAl region in rats altecr one day of cerebral ischemia/reperfusion and that apoptosis can be reduced by using potassium channel blocker IBTX. Intraventricular injection of IBTX may produce protective effects though the apoptosis may mentioned above.