人尿激肽原酶对急性局灶性脑缺血再灌注损伤大鼠细胞凋亡的影响

目的 研究人尿激肽原酶(HUK)对大鼠急性局灶性脑缺血再灌注(FCIR)损伤后细胞凋亡数量及B细胞淋巴瘤/白血病-2(Bcl-2)、Bcl-2联合X蛋白(Bax)蛋白表达的影响.方法 84只雄性SD大鼠分为假手术组(12只)、脑缺血再灌注(IR)组(36只)、HUK处理组(36只),IR组和HUK处理组剩余大鼠又按照再灌注时间6 h、12 h、24 h、72 h、168 h分为5个亚组(均为6只).建立大鼠大脑中动脉FCIR模型.假手术组、IR组及HUK处理组中各取6只SD大鼠用于测定梗死体积,其余大鼠用于观察神经功能缺陷评分、TIJNEL法及免疫组化检测凋亡细胞数量及凋亡蛋白Bcl-2、Bax的表达.结果 HUK处理组神经功能缺陷评分、梗死灶体积、除168 h亚组外的各时 间点的凋亡细胞数及Bax蛋白表达均显著少于IR组(P＜0.05),除168 h亚组外的各时间点的Bcl-2蛋白表达均显著高于IR组(P＜0.05).结论 HUK对FCIR后的脑组织起保护作用,其机制可能为损伤后3 d内通过上调Bcl-2、下调Bax蛋白表达来抑制细胞凋亡.

Effects of human urinary kallikrein on cell apoptosis of rats with acute focal cerebral ischemia-reperfusion injury

Objective To study the effects of human uriilary kallikrein(HUK)on the number of apoptotic cells and the expressions of Bcl-2 and Bax proteins in rats after focal cerebral ischemia and reperfusion(FCIR) injury. Methods Eighty-four Spmque-Dawley(SD)male rats were randomly divided into sham-operated group(n=12),ischemia-reperfusion group(n=36),and HUK-treated group (n=36). Transient focal cerebml ischemia models were established by middle cerebml artery occlusion.Six rats were chosen from sham-operated group,ischemia-reperfusion group,and HUK-treated group for measuring infarct sizes.The rest were used to evaluate neurologic fhnction impaiment and measure the nunlber of apoptotic cells and Bcl-2 or BaX protein positive cells in cerebral cortex with TUNEL and immunohistochemistry.The latter 2 groups were subdivided into 6,12,24,72,168 h reperfusio groups (each n=6). Results The neurologic function impairmlent score,the infarct sizes,the apoptotic cells and the expression of Bax protein of HUK-treated group at different time points (except 168 h group)significantly decreased compared wilh those of ischemia-reperfsion group (p＜0.05).The expression of Bcl-2 protein of HUK-treated group at different time points(except 168 h group) remarkably increased compared with that of ischemia-reperfusion group(P＜0.05). Conclusions HUK can excrt a protection against FCIR injury, maybe through up-regulating Bcl-2 and down-regulating Bax protein in the initial 3 d of FCIR injury to decrease the number of apoptotic cells