卵巢切除后脑缺血再灌海马CA1区ET-3的表达

目的 :采用卵巢切除合并脑缺血再灌动物模型 ,通过免疫组织化学方法探讨脑缺血再灌损伤中雌激素与内皮素 3(ET 3)相互关系。方法 :将 5 4只成年雌性昆明小鼠随机分为三组 :①缺血再灌组 (IR) ,双侧颈总动脉结扎 7min ,再灌 1,3,5 ,14d (每个时间点 ,n =6 ) ;②卵巢切除 /缺血再灌组 (OVX/IR) ,在缺血再灌前1周作卵巢切除术 ,再灌 1,3,5 ,14d (每个时间点 ,n =6 ) ;③假手术对照组 (n =6 )。结果 :对照组海马CA1区可见少量散在分布的ET 3免疫阳性细胞 ,实验组各时间点ET 3免疫阳性细胞数与对照组相比均明显增多 (P<0 .0 1)。缺血再灌 1d时 ,OVX/IR组ET 3阳性细胞数明显高于IR组 (P <0 .0 1) ;5d时 ,OVX/IR组和IR组ET 3阳性细胞数达高峰。结论 :本实验提示雌激素可能在缺血再灌的早期参与对ET 3的调控 ,对神经元存活起保护作用。

Expression of ET-3 in hippocampal CA1 of ovariectomied mice after cerebral ischemia/reperfusion

Objective To detect the expression of endothelins-3 (ET-3) immunoactivity in hippocampal CA1 of ovariectomied (OVX) mice after ischemia/reperfusion (IR), and to further explore the relationship between estrogen and ET-3.Methods Fifty-four adult female mice were randomly divided into 3 groups. ① IR group: the bilateral common carotid occlusion (BCCO) was carried out for 7 min on the 1st, 3rd, 5th and 14th day of reperfusion. ② OVX/IR group: firstly the ovariectomy was performed, and after a week, BCCO was carried out for 7min on the 1st, 3rd, 5th and 14th day of reperfusion (each time spot, n=6). ③sham-operated group (n=6). Results Few ET-3 positive cells were diffusely distributed in the hippocampal CA1 region in the control group, whereas the expression of ET-3 increased in the experimental groups. The number of ET-3 positive cells significantly increased in the OVX/IR group compared with that of the IR group 1 d after the reperfusion (P<0.01). It reached the maximum in both the OVX/IR and IR group on the 5th day of the reperfusion.Conclusion Estrogen is involved in the regulation of ET-3 in the early stage of the reperfusion, and probably plays a protective role in the survival of neurons.