大鼠脑出血后神经元凋亡与caspase-3表达的关系

目的　研究大鼠实验性脑出血模型中神经细胞凋亡发生的规律以及与caspase 3表达的关系 ,观察caspase抑制剂zVADfmk对出血性脑损伤的保护作用。方法　应用立体定向技术 ,将自体不凝血注入大鼠尾状核区制备脑出血模型 ,将动物随机分为假手术组、出血组和zVADfmk干预组 ,分别在不同时间点断头取脑 ,连续切片作TUNEL染色和caspase 3免疫组化染色。 结果　脑出血后 6h血肿内部及周边组织出现TUNEL阳性细胞 ,72h达高峰 ,2周时仍有少量表达 ;caspase 3在脑出血后 6h表达明显增高 ,2 4h达到高峰 ,各组与假手术组之间差异显著 (P <0 .0 5 )。脑出血后的TUNEL阳性细胞与caspase 3的表达呈正相关 (r =0 .6 0 7,P <0 .0 5 ) ,且caspase 3的高峰时间早于凋亡的发生。经caspase 3抑制剂干预 ,血肿周围组织TUNEL阳性细胞明显减少 ,与对照组相比差异显著 (P <0 .0 5 )。结论　凋亡机制参与了脑出血后继发性损伤的过程 ,而caspase 3的激活在其中起着重要作用 ,通过阻断caspase的激活可以减少脑出血后神经细胞凋亡的发生

Expression of caspase-3 in neuronal apoptosis after intracerebral hemorrhage in rats

Objective To investigate neuronal apoptosis in the region of experimental intracerebral hemorrhage(ICH) in rats and its association with the expression of caspase 3, and to observe the effect of caspase inhibitor zVADfmk on the brain injury after ICH. Methods\ ICH was induced in rats by injecting stereotactic infusion autologous blood into the caudate nucleus. The male rats were randomly divided into hemorrhage group, sham operation group, zVADfmk treatment group and hemorrhage group which was also divided into several different time point groups. TUNEL method was used to detect apoptosis, and immunohistochemitry method to detect the expression of caspase 3 in cerebral tissues at different time. Results\ After 6 hours, TUNEL positive cells appeared in the ICH model and were still present for more than 2 weeks after ICH, peaking on the 3rd day. caspase 3 expression preceded apoptosis, increasing obviously after 6 hours, peaking after 24 hours and declining thereafter. The expression of caspase 3 was positively correlated with apoptotic cells(r=0.607, P< 0.05) .The quantity of TUNEL positive cells within 3 days after ICH were significantly reduced by treating with caspase inhibitor zVADfmk (P<0.05). Conclusion\ Apoptosis mechanisms may mediate some of the brain injury after ICH. Neuronal apoptosis after ICH is associated with the activation of caspase 3.