自由基清除剂预处理对大鼠脑缺血再灌注损伤后脑组织细胞凋亡及其相关蛋白表达的影响

Effects of edaravone pretreatment on cells apoptosis and expression of proteins related to apoptosis in cerebral tissues following ischemia-reperfusion in rats

目的探讨自由基清除剂依达拉奉预处理对大鼠脑缺血再灌注损伤后神经细胞凋亡及其相关蛋白Bcl-2、Bax、热休克蛋白70(HSP70)表达的影响。方法将45只雄性SD大鼠随机分为假手术组、对照组、依达拉奉预处理组,每组15只。采用线栓法制作大鼠缺血2h再灌注24h模型。预处理组大鼠建模前12h腹腔注射依达拉奉(3mg/kg),对照组给予等容量生理盐水。再灌注24h后断头取脑,应用免疫组织化学法检测Bcl-2、Bax、HSP70蛋白表达,末端脱氧核糖核酸转移酶介导的原位缺口末端标记法检测凋亡细胞。结果依达拉奉预处理组和对照组大鼠缺血周围脑组织中凋亡细胞和Bcl-2、Bax及HSP70阳性细胞数比假手术组均明显增加(P<0.01);与对照组比较,其凋亡细胞和Bax阳性细胞数均明显减少(P<0.01),而Bcl-2和HSP70阳性细胞数明显增加(P<0.01)。结论细胞凋亡在缺血再灌注损伤中起着重要作用;依达拉奉可能通过上调Bcl-2、HSP70蛋白表达、下调Bax蛋白表达减轻大鼠脑缺血再灌注后的细胞凋亡,增加脑缺血再灌注损伤耐受性,从而起到神经保护作用。

Objective To study the effect of edaravone pretreatment on neuronal apoptosis and the expression of the proteinsr elated to the apoptosis including B cell lymphoma/lewkmia-2（Bcl-2）,Bcl-2-associated x protein（Bax）,heat shock protein 70（HSP70）i n the cerebral tissues after ischemia-reperfusion in rats.Methods Forty-five healthy male SD rats were randomly divided into 3 groupso f 15 animals each including sham-operation group,control group and edaravone pretreatment group.The focal cerebrali schemia-reperfusion model in the rats was established by the middle cerebral artery occlusion（MCAO）for 2 hours followed byr eperfusion for 24 hours.The edaravone（dose：3 mg/kg）was intraperitoneally injected 12 hours before the ischemia in edaravonep retreatment group.The neuronal apoptosis and expressions of bcl-2,bax and HSP70 in the cerebral tissues 24 hours after ther eperfusion were determined respectively by terminal deoxynucleotidyl transferase dUTP nick end labeling（TUNEL）andi mmunohischemical technique.Results The number of apoptosis cells and the numbers of bcl-2-,bax-and HSP70 Positive cells weres ignificantly more in the control and edaravone pretreatment groups than that in the sham-operation group（P0.01）.The number ofa poptosis cells and bax-positive cells was significantly fewer,and the numbers of bcl-2-positive cells and HSP70-positive cells weres ignificantly more in edaravone pretreatment group than those in the control group（P0.01）.Conclusions The cells apoptosis may playa n important role in the injury to the cerebral tissues induced the ischemia-reperfusion.Edaravone may reduce the apoptosis of thec erebral neurons induced by the ischemia-reperfusion through up-regulating Bcl-2 and HSP-70 expressions and down-regulating Baxe xpression.Therefore,edaravone is of protective effect on the cerebral tissues after the ischemia-reperfusion.