大鼠暂时性全脑缺血再灌后海马区凋亡检测

目的:检测四血管阻塞大鼠全脑缺血20分钟再灌后不同时间点海马区凋亡细胞.方法:TUNEL法标记,常规光镜观察.结果:再灌后第一天没有明显的阳性细胞,第二天出现散在的阳性细胞,主要位于海马的h1区;第三天阳性细胞分布范围扩至最大,见于海马的pm区、h1区、h2区、h3～5区.但密度稍低,尤其是h2区;第四天阳性细胞达到高峰,第七天阳性细胞明显减少,仅见于pm区、h1区的前中2/3.TUNEL标记阳性的细胞以锥状神经元为主,主要位于海马h1区.高倍光镜显示阳性细胞呈坏死和凋亡两种状态.凋亡的阳性信号存在于核内、胞体和/或突起中.结论:实验提示大鼠全脑缺血再灌后海马区出现的延迟性缺血性损伤是由凋亡作为主要机制参与的神经元死亡方式,且以海马h1区锥状神经元为主.

IN SITU DETECTION OF APOPTOSIS IN RAT HIPPOCAMPUS AFTER TRANSIENT GLOBAL ISCHEMIA

The objective of the study is to clarify meachanism of delayed neuron death occurring in rat hippocampus follwing transient global ischemia. TUNEL staining was used to detect apoptosis in the hippocampus of four-vessel occlusion rat model(n = 3). Our results showed that on the 2nd day reperfusion TUNEL-positive neurons was sparsely located in the h1 zone of the hippocampus, then markedly increased on the 3rd day, and extended to the paramediam, h1, h2 and h3-5 zone. They reached the maxium of density on the 4th day, but disappeared in the h2 zone. On the 7th days, positive signals declined, only located in the h1, pm zone. Our findings suggested that the apoptosis might contribute to the delayed pyramidal neurons death following transient global ischemia.