脑缺血再灌注后脑内血红素氧合酶-1表达的时相变化

目的 :研究局灶性脑缺血再灌注时血红素氧合酶 1(HO 1)在脑内的表达及其作用。方法 :采用梗塞大鼠大脑中动脉制备脑缺血再灌注模型 ,对 66只大鼠脑缺血及缺血再灌注后不同时间点进行HO 1免疫组化及病理学研究 ,并用计算机图像分析技术计算HO 1表达的强弱。结果 :单纯缺血 1h后皮质及海马即有HO 1阳性神经元胶质细胞的表达 ,梗塞 1h再灌 0 .5hHO 1表达与单纯缺血基本相同。随着再灌注时间的延长 ,HO 1的表达逐渐增强 ,到再灌 12h时达最高 ,以后逐渐下降 ,再灌 7天后仍有HO 1表达。HO 1主要分布在灶周皮质、梗塞皮质区、梨状皮质内的神经元及胶质细胞 ,丘脑、下丘脑、海马齿状回的神经元。结论 :局灶性脑缺血再灌注时脑内HO 1表达变化 ,是脑组织对自身损伤的重要恢复机制之一。HO 1自身具有脑保护作用并通过其下游产物CO起作用

The Time Phase Changement of Heme Oxygenase-1 Protein Expression in Focal Transient Cerebral Ischemia in Rats

Objective: To appreciate the expression of heme oxygenase protein and its role during focal transient cerebral ischemia in rats.Method: The expression of heme oxygenase-1(HO-1) protein in different time phase of cerebral tissue in 66 rats during focal transient cerebral ischemia were investigated by means of immunohistochemistry、pathological study and computer image analysis.Results: HO-1 expression was observed in the ipsilateral cerebral cortex infarction area and hippocampus at the time of 1h after ischemia. HO-1 expression in ischemia 1 h reperfusion 0.5h group was similar as that in ischemia 1h group. With the reperfusion time prolonging, the expression of HO increased, peaked at 12 h and then slow down, but last till 7 th day after reperfusion. Both HO positive neurons and HO positive glias were observed in the ipsilateral infarction border area、frontal and cingulated cortex. HO positive neurons were observed in thalamus、hypothalamus and dentate gyrus.Conclusion: The expression of HO-1 protein is evidently not without significant physiological consequences in the recovery of neuronal tissue from ischemic injury in focal transient cerebral ischemia in rats. The cerebral protection of HO-1 may relate to itself and its downstream product “carbon monoxide”.