脑缺血再灌注论文：β-ARB对大鼠大脑局灶性缺血再灌注后Bcl-2、Bax和NGF表达的影响

脑缺血再灌注论文：β-ARB对大鼠大脑局灶性缺血再灌注后Bcl-2、Bax和NGF达的影响 脑缺血再灌注论文:β-ARB对大鼠大脑局灶性缺血再灌注后Bcl-2、Bax和NGF表达的影响 【中文摘要】观测在局灶性脑缺血再灌注损伤后各个时间用普萘洛尔(Propranolol)、美托洛尔(Metoprolol)治疗后的大鼠细胞凋亡和病理形态学结果。观测Bcl-2、Bax和NGF在局灶性脑缺血再灌注中的表达情况及普萘洛尔(Propranolol)、美托洛尔(Metoprolol)治疗对其表达情况的影响，探讨在局灶性脑缺血再灌注中β-肾上腺受体阻滞剂(β-adrenergicreceptor blockers，β-ARB)的神经保护作用机制方法:?成年、雄性wistar大鼠72只，体重230?5g，后随机分为4组，假手术组(n=18)、模型组(n=18)、普萘洛尔给药组(n=18)、美托洛尔给药组(n=18)。每组又分为12h、24h、48h三个亚组。?.采用线栓法制备大鼠右侧大脑中动脉局灶缺血(middle cerebral arteryocculusion，MCAO)。?.HE染色观察脑组织形态病理学变化;采用DNA原位末端缺口标记法(TUNEL)检测神经元凋亡;免疫组化法测定大鼠脑缺血再灌注不同时间Bcl-2、Bax和NGF的平均灰度值。结果:1.HE染色发现:与模型组比较，普萘洛尔给药组和美托洛尔给药组在再灌注各个时间点神经元损伤显著减轻。2免疫组化显示:与假手术组比较，模型组Bax和NGF蛋白阳性表达在12h小时升高，24h达高峰(P,0.05)。模型组Bcl-2蛋白阳性表达在12小时达高峰，后逐渐减低(P,0.05)。与模型组相比，普萘洛尔给药 组和美托洛尔给药组的Bcl-2蛋白阳性表达均较显著增加(P, 0.05)，而Bax蛋白阳性表达则明显减少(P,0.05)，但均多于假手 术组(P,0.05)。与模型组相比，美托洛尔给药组的NGF蛋白阳性表 达无明显差异，而普萘洛尔给药组的NGF蛋白阳性表达显著减少 (P<0.05)。3.脱氧核糖核苷酸末端染色显示:在假手术组大脑半球和 模型组手术对侧发现很少量的凋亡细胞，考虑是细胞的生理性坏死; 大量的阳性细胞可在模型组缺血区见到(P<0.05);在普萘洛尔给药 组和美托洛尔给药组的阳性细胞数均明显减少(P,0.05)且无显著差 异(P>0.05).结论:1.HE染色显示:在神经功能损伤和梗死面积方 面，与模型组相比，在不同时间点经美托洛尔给药组和普萘洛尔治疗 有缓解2.普萘洛尔和美托洛尔均通过减轻脑缺血再灌注后神经损伤 实现了神经保护作用。3.普萘洛尔和美托洛尔均对脑缺血再灌注损伤 引起的海马及皮层的神经细胞凋亡有明显抑制作用。4.在大脑局灶缺 血再灌注损伤中普萘洛尔和美托洛尔的神经元起保护作用均通过抑 制Bax的表达和促进Bcl-2表达来实现。 【英文摘要】: To observe the effect of MTT-treatment and Propranolol-treatment on the histologicoutcome，apoptosis at different time points on the model of focal cerebral ischemia-reperfusioninjury in rats，To investigate the expression of Bax、Bcl-2 and NGF in the model of focalcerebral ischemia-reperfusion and the neuroprotective effect of MTT-treatment andPropranolol-treatment，To explore the neuroprotective mechanism ofβ-adrenergic receptorblockers in the model of focal cerebral ischemia-reperfusionModels:Seventy-two male adult wistar rats were divided into sham operation group、ischemia-reperfusion group、Propranolol-treatment and MTT-treatment grouprandomly,reperfusion 12h、24h、48h three sub-groups were divided in each group according totheir reperfused time point.The model of Focal cerebral ischemia-reperfusion injury was madeby line embolism method.HE staining of pathological changes in brain tissuemorphology;neuronal apoptosis was detected by TUNEL,to observe Bax、Bcl-2 and NGFexpression was by immunohistochemisery.Resules: 1.HE staining shows that infarction and neuronal injury was relieved at different timepoints in the MTT-treatment group and Propranolol-treatment compared with I-Rgroup .2.Expresion of Bax and NGF positive cells was found after cerebral ischemia followedby reperfusion 12h in the penumbra zone,it reached a peak level at 24h afterreperfusion(P<0.05), then declined,expression of Bcl-2 positive cells reached a peak level aftercerebral ischemia followed by reperfusion 12h in the penumbra zone，thendeclined(P<0.05).Expression of Bax in MTT-treatment group and Propranolol-treatment groupat all time points were distinctly lower than ischemia-reperfusion group(P<0.05),but upper thansham group(P<0.05).Expression of Bcl-2 in MTT-treatment group and Propranolol-treatmentgroup at all time point were distinctly upper than ischemia-reperfusion group. Expression ofNGF positive cells was found in MTT-treatment group and ischemia-reperfusion group almostthe same. Expresion of Bax in Propranolol-treatment group at all time points were distinctlylower than ischemia-reperfusion group(P<0.05).3.Ischemia-reperfusion group of thecontralateral cerebral hemisphere and sham operation group occasional apoptoticcells ,speculate that is physiological neuronal necrosis.A large number of TUNEL-positive cellswere observed in I-R group (P<0.05),TUNEL-positive cells were obvious reduced in theMTT-treatment group and Propranolol-treatment group ,but higher than the sham group(P<0.05 ).Conclusion: 1.Focal cerebral ischemia and reperfusion model were success fully replicated.therats development typical symptoms of neurological impairment.HE staining results in line withpathological process.2.MTT-treatmentand Propranolol-treatment could attenuate cell death aftercerebral ischemia-reperfusion show neuroprotective effect.3.MTT-treatmentand Propranolol-treatment obviously inhibited transient focal cerebral ischemia induced apoptosis in cortex andhippocampus,4.Metoprolol and Propranolol obviously inhibited focal cerebralischemia-reperfusion injury through down-regulate the expression of Bax and up-regulate the expression of Bcl-2 ,and show a neuroprotective effect. 【关键词】脑缺血再灌注 Bax Bcl-2 神经生长因子 β-肾上腺 受体阻滞剂 【英文关键词】Propranolol Metoprolol cerebral ischemia-reperfusion Bax Bcl-2 NGF apoptosis β-adrenergic receptor blockers 【目录】β-ARB对大鼠大脑局灶性缺血再灌注后Bcl-2、Bax和 NGF表达的影响 中文摘要 5-6 ABSTRACT 6-7 主要英 文缩略词表 8-9 前言 9-11 材料与方法 11-14 实 验结果 14-15 表及图 15-18 讨论 18-21 结论 21-22 参考文献 22-24 综述 24-30 参考文献 28-30 个人简介 30-31 致谢 31