血管活性肠肽抑制大鼠脑缺血诱导的细胞凋亡和iNOS表达

Vasoactive Intestinal Peptide Attenuates Apoptosis and iNOS Protein Expression Induced by Cerebral Ischemia in the Rat

目的探讨脑内注射血管活性肠肽(VIP)对大鼠脑缺血再灌注损伤的神经保护作用。方法通过线栓技术闭塞大脑中动脉(MCAO)2h诱导建立暂时性局部脑缺血模型后,大鼠侧脑室内注射VIP。采用TTC染色测定大鼠脑梗死体积;TUNEL染色评定缺血边缘区细胞凋亡;Western Blotting分析脑内iNOS蛋白含量。结果MCAO后1d,VIP注射大鼠脑梗死体积较对照组明显缩小,减少约28%(P<0.05);缺血边缘区TUNEL阳性细胞数目减少(P<0.05);脑组织iNOS蛋白表达明显降低(P<0.05)。结论大鼠脑内注射VIP可以抑制脑缺血再灌注诱导的细胞凋亡,减小梗死体积,具有神经保护作用;VIP抑制细胞凋亡的作用可能与iNOS蛋白表达降低有关。

Objective To explore the neuroprotective action of vasoactive intestinal peptide（VIP）on ischemia and reperfusion in the rat.Methods VIP was given via intracerebroventriclar injection after a 2 hour transient middle cerebral artery occlusion using filament model.The infarct volume was investigated with TTC stain.Apoptosis in the ischemic boundary zone were evaluated with TUNEL stain.Western blotting were used to analyze the iNOS protein expression as well.Results After VIP injection,the relative infarct volume of rats was significantly reduced by approximately 28% campared to that of the control groups at 1 day（P〈0.05）.The number of TUNEL positive cells was significantly decreased in the ischemic boundary zone,and then the expression of iNOS was remarkablely decreased as well（P〈0.05）.Conclusion VIP has a neuroprotective effect on cerebral ischemia and reperfusion.The mechanism seems to involve decreasing the apoptosis and down-regulating the iNOS expression.