雌二醇对去势沙鼠脑缺血再灌注损伤后脑组织中NO和NOS的影响

目的　观察雌二醇对去势沙鼠脑缺血再灌注脑损伤的保护作用。方法　去势雌性沙鼠 30只 ,随机分为假手术组、缺血再灌注组和雌二醇干预组。采用夹闭双侧颈总动脉法复制沙鼠脑缺血再灌注模型 ,缺血 7min再灌注 12h ,取脑组织测定脑组织中一氧化氮 (NO)含量、一氧化氮合酶 (NOS)活力的变化 ,并取脑组织观察海马CA1区神经细胞的病理改变。结果　缺血再灌注组脑组织中NO含量明显增高 ,NOS活力明显降低 ,与假手术组比较有显著差异 (P <0 . 0 1) ;雌二醇干预组脑组织中NO水平明显降低 ,NOS活力有所增高 ,与缺血再灌注组比较有显著差异 (P <0 . 0 1) ;缺血再灌注组脑组织海马CA1区神经细胞损伤明显 ,脑组织水肿明显 ;雌二醇干预组神经细胞损伤明显减轻。结论　预防性应用雌二醇能明显减轻缺血再灌注所造成的神经细胞损伤 ,对脑缺血再灌注损伤有保护作用。

Effects of estradiol on NO and NOS level in cerebral ischemia-reperfusion damaged tissues in castrated female gerbils

Objective: To observe the protection effects of estradiol on experimental cerebral ischemia reperfusion injury in castrated female gerbils. Methods: Thirty castrated female gerbils were randomly divided into three groups: sham operation, ischemia-reperfusion and estradiol prevention. Cerebral ischemia-reperfusion model were made by clipping bilateral common carotid arteries for seven minutes in both the second and the third groups, but not in the sham operation group. Twelve hours after the operation, gerbils were sacrificed. The level of NO and the activity of NOS in brain tissue were measured. Neurocyte structure in hippocapus CA 1 area was observed with optical microscope. Results:In ischemia-reperfusion group,the level of NO in the brain tissue was higher and the activity of NOS was lower compared to that in the sham operation group(P<0.01).In estradiol group,the level of NO in the brain tissue was lower and the activity of NOS was higher compared to that in the ischemia-reperfusion group(P<0.01). Neurocyte damages and edema in hippocapus CA1 area was obvious in ischemia-reperfusion group. The neurocyte damages in estradiol group were obviously alleviated.Conclusion:Estradiol can obviously protect neurocytes from the damage caused by ischemia-reperfusion.