地塞米松和苯妥英钠对癫痫大鼠脑内的GFAP和Fos表达的抑制作用

目的：探讨糖皮质激素（GC）的抗痫效应和抗痫机制。方法：动物行为学观察和免疫细胞化学染色。结果：戊四氮（PTZ）可诱发癫痫大发作，如诺在注入PTZ前30min先注入地塞米松或苯妥英钠（DPH）能减轻或抑制大鼠癫痫发作症状。免疫细胞化学染色结果表明，PTZ致痫组大鼠大脑皮质、海马回、齿状有大量肥大的胶质原纤维酸性蛋白（GFAP）阳性的星形胶质细胞。GC或DPH抗痫组GFAP免疫反应明显减弱，阳性细胞数量减少，突起短而少，Fos蛋白在PTZ组大鼠致痫后1－1．5h有大量表达，而在上述两抗痫组显著少于PTZ致痫组。结论：1．通过与苯妥英钠（传统抗痫药）的抗痫效果相比较，进一步证明糖皮质激素具有抗痫效应。2．糖皮质激素的抗痫机制可能与抑制星形胶质细胞的活动有关。3．Fos蛋白表达的变化与癫痫活动有直接关系。

INHIBITORY EFFECT OF DEXAMETHASONE AND DIPHENYLHY| DANTOIN ON THE EXPRESSION OF GFAP AND Fos IN THE BRAIN OF EPILEPTIC RATS

Objective To explore the antiepileptic effect and mechanism of glucocorticoid. Methods Animal behaviour observation and immunocytochemical staining. Results Major epilepsy was induced by pentylenetetrazole(PTZ).Dexamethasone or diphenylhydantoin(DPH) administered in rat 30?min before administration of PTZ could suppress or inhibit epileptiform.Immunocytochemistry demonstrated that there was a large number of hypertrophic astrocytes with GFAP immunoreaction in cerebral cortex,hippocampal gyrus and dentate gyrus of epileptic rats induced by PTZ.The immunoreaction of GFAP was obviously weakened,the number of positive cells was reduced,the processes were shorter and less in both groups of antiepilepsy by GC or DPH.The expression of Fos protein was in a great quantity in cerebral cortex 1 to 1^5 hours after seizure induced by PTZ,whereas their expressions were remarkable suppressed in GC or DPH antiepileptic groups. Conclusion 1^The antiepileptic effect of GC was further proved by comparing with the antiepileptic effects of DPH(a traditional antiepileptic drug). 2^Inhibited activity of astrocytes might be involved in antiepileptic mechanism of GC. 3^The change of expression of Fos protein might be closely related to epileptic actions. [