静脉注射用免疫球蛋白对大鼠脑缺血再灌注损伤的影响

Intravenous Immune Globulin in Activation of Complement System and Cerebral Edema after Cerebral Ischemia and Reperfusion in Rats

目的探讨静脉注射用免疫球蛋白(Intravenous immune globlin,IVIG)干预对大鼠脑缺血/再灌注损伤后补体系统激活和脑水肿的影响。方法SD大鼠随机分为假手术组、山梨醇注射组(山梨醇组)和IVIG注射组(IVIG组)。采用Longa改良线栓法制作大鼠大脑中动脉缺血/再灌注模型,造模后进行运动功能评分。用免疫组化法测定大鼠脑组织补体成分C5a的表达,用干湿重法测定脑含水量。结果大鼠脑缺血/再灌注后,IVIG组和山梨醇组术侧补体C5a在12h即可见表达,第3天达到高峰,第7天仍高于健侧。山梨醇组和IVIG组术侧脑含水量在脑缺血/再灌注12h上升,第1天到达高峰。补体C5a的表达增加与脑含水量的上升趋势基本一致。在IVIG组各时间点补体C5a表达水平和脑含水量均较山梨醇组低,差异有统计学意义(P<0.05)。结论脑缺血/再灌注后补体系统激活加重了脑水肿,IVIG能通过抑制补体有效减轻脑水肿。

Objectives To investigate intravenous immune globulin(IVIG) on the activation of complement system and cerebral edema after cerebral ischemia and reperfusion in rats.Methods Sprague Dawley rats were randomly assigned into groups sham operation,D-sorbitol and IVIG.The middle cerebral artery ischemia-reperfusion models were established by advanced Longa′s nylon monofilament occlusion method.The expression of complement component C5a was determined by immunohistochemical method and the brain water content by dry weight/wet weight method.Results After cerebral ischemia and reperfusion,the expressions of complement C5a were seen in the operated side of groups IVIG and D-sorbitol,reaching the peak on day 3 and higher than in the healthy side even on day 7.The brain water content in the operated side elevated at hour 12 in groups D-sorbitol and IVIG,reaching the peak on day 1.The increase of complement C5a was basically coincident with the rise trend of brain water content.The complement C5a expression and brain water content at different time points were lower in group IVIG than in D-sorbitol,the difference was significant(P<0.05).Conclusions The activation of the complement system after cerebral ischemia and reperfusion aggratates cerebral edema.IVIG can effectually reduce cerebral edema by inhibiting the activation of complement system.