脑室内注射胰岛素对大鼠脑海马CA1区神经元迟发性死亡的保护作用

Intraventricular injection of insulin attenuates delayed neuronal death in rat hippocampal CA1 region

目的 观察大鼠全脑缺血后经脑室注射胰岛素对海马区神经元病理形态学改变的影响 ,探讨胰岛素对海马区神经元迟发性死亡的作用 .方法 利用改良四血管闭塞法 ,建立大鼠全脑缺血模型 .缺血再灌注后即刻经脑室注 1U胰岛素 ,于缺血再灌注后 1,3,5和 7d断头取脑 ,光镜下计数海马区正常神经元 .结果 缺血再灌注后 3,5及 7d治疗组鼠海马 CA1区正常神经元计数为 1(6 8.6± 10 .9) ,(133.5±10 .5 ) ,(10 5 .6± 10 .1) ,缺血组则为 (87.4± 5 .1) ,(4 5 .4±6 .1) ,(10 .5± 3.4) .两组比较存在显著差异 (P <0 .0 1) .结论 胰岛素对缺再性脑损伤具有中枢直接保护作用 。

AIM To investigate the effect of insulin on delayed neuronal death in rat hippocampal CA1 region and to observe the histopathological changes of CA1 region after intraventricular administration of insulin after globe brain ischemia. METHODS Four vessel occlusion was used to establish the globe brain ischemia model in rat. Insulin was given to rat brain ventricle immediately after ischemia. The brain of rat was removed in 1, 3, 5, 7 days after ischemia respectively. The number of normal neurons in hippocampalCA1 region was counted under the light microscope. RESULTS The number of normal neurons in insulin treated group in 3, 5, 7 d after ischemia was (168.6±10.9), (133.5±10.5) and ( 105.6 ±10.1) mm -2 , respectively, while in ischemic group, the number of the normal neurons was (87.4±5.1), (45.4±6.1), (10.5±3.4) mm -2 respectively. There was a significant difference between the two groups ( P <0.01). CONCLUSION Insulin has a direct neuroprotective effect on rat hippocampal CA1 region which can attenuate the delayed neuronal death.