戊四氮致痫大鼠皮质和海马内GFAP、cyclin D1及脑和脑脊液17β-雌二醇和孕酮浓度变化

VARIATIONS IN THE CONCENTRATIONS OF 17β-E2 AND PROGESTIN IN BRAIN AND CEREBROSPINAL FLUID OF RATS WITH SEIZURES INDUCED BY PENTYLENETETRAZOLE

目的研究癫痫发作后脑和脑脊液中17β-雌二醇和孕酮含量的变化。方法将雌性SD大鼠随机分为戊四氮(PTZ)致痫组和生理盐水对照组。(1)用免疫组织化学方法观察大鼠大脑皮质和海马星形胶质细胞胶质原纤维酸性蛋白(GFAP)含量的变化;(2)用Western blot方法检测大鼠大脑皮质和海马细胞周期素D1(cyclin D1)表达的变化;(3)采用放免法测定大鼠大脑皮质和海马组织匀浆及脑脊液中17β-雌二醇和孕酮含量的变化。结果免疫组织化学染色结果显示癫痫发作4h后在海马CA3区、CA1区和皮质内GFAP免疫反应明显增强(P<0.05);Western blot结果显示癫痫发作2h后cyclin D1的表达在皮质和海马均较对照组明显增强(P<0.05);放射免疫分析结果显示,癫痫发作后,皮质、海马和脑脊液的17β-雌二醇的浓度有不同程度增高,致痫8h后恢复正常,孕酮的浓度在皮质和脑脊液则呈下降趋势。结论戊四氮致痫时皮质及海马内星形胶质细胞激活、增殖,内源性雌激素合成增多,同时孕酮浓度降低,说明雌性激素在癫痫的形成和维持中发挥作用。

Objective To explore the excitation and proliferation of astrocytes and the variations in the concentration of 17βE2 and progestin during seizure induced by pentylenetetrazole. Methods Female Sprague-Dawley rats were divided into 2 groups at random： the control group and PTZ group. Immunohistochemistry （SABC） was used to detect the immunoreaction of GFAP, Western blotting was employed to show the expression of Cyclin D1, and radioimmunoassay was used to assess the concentration of 17βE2 and progestin in the brain and cerebrospinal fluid. Results （1） SABC staining indicated that the expression of GFAP in hippocampus and cortex was significantly increased 4h after seizure onset （P〈0.05）. （2） Western blot results indicated that the expression of cyclin D1 was remarkably increased in hippocampus and cortex of rats 2h after seizure onset. （3） The concentration of 17β-E2 increased in cortex, hippocampus and CSF, and returned to normal 8h after seize. However, the concentration of progestin decreased in cortex and hippocampus after seize. Conclusion The results indicate that astrocytes were activated and proliferated, and 17βE2 was synthesized and increased, while the concentration of progestin decreased. All of these indicate that gonadal steroid was induced by pentylenetetrazole. involved in the onset and development of epilepsy induced by pentylenetetrazole.