局灶性脑缺血再灌注后大鼠血浆和海马皮质醇含量变化

Changes of cortisol content in plasma and hippocampus after focal cerebral ischemia-reperfusion in rats

目的 :探讨脑缺血再灌注后糖皮质激素与海马神经元损伤的关系 ,以及糖皮质激素对卒中后痴呆发病的影响。方法 :采取大脑中动脉阻塞模型 ,通过放射免疫方法测定脑缺血再灌注后模型大鼠再灌注 2h、6h、12h和 2 4h不同时点的血浆和海马皮质醇含量变化。结果 :模型组在再灌注 4个时点糖皮质激素含量都有增高 ,同假手术组、正常组相比有显著差异 (P <0 0 5 )。血浆、海马中皮质醇含量都以再灌注 6h最高。HE染色海马神经元损伤随再灌注时点的延长 ,呈进行性加重。结论 :脑缺血再灌注后 2 4h内存在血浆、海马皮质醇含量的增高 ,这可能是加重海马神经元损伤 ,引发卒中后痴呆发生的原因之一。

AIM: To investigate the relationship between glucocorticoid (Gc) and injury of hippocampus neurons and the effect of Gc on dementia episode after cerebral ischemia-reperfusion. METHODS: The rat model of middle cerebral artery occlusion (MACO) was established. Cortisol contents in hippocampus and plasma of the model rats were examined by means of the radioimmunoassay at 2 h, 6 h, 12 h, 24 h after reperfusion. RESULTS: The levels of cortisol content in model group were significantly higher than those in sham group and normal group both in hippocampus and plasma. The highest cortisol content was observed at 6 hours after reperfusion. HE staining showed that the impairment of hippocampus neurons was aggravated progressively with reperfusion interval elongating. CONCLUSION: The increased cortisol in hippocampus and plasma, after 2 h cerebral ischemia and 24 h reperfusion, could aggravate the injury of hippocampus neurons and lead to dementia post stroke.