糖皮质激素的抗痫作用及其与γ-氨基丁酸的关系

为了探讨糖皮质激素的抗癫痫效应和作用机制， 本研究观察了糖皮质激素对戊四氮诱导的慢性点燃型癫痫大鼠的行为和脑电图的影响， 并应用免疫细胞化学双重染色技术探查了大脑皮质神经元内糖皮质激素受体（ＧＲ） 与γ－ 氨基丁酸（ＧＡＢＡ） 的共存情况。结果显示， 在慢性点燃型癫痫大鼠， 在点燃后的第３ 天或第１５ 天， 先经静脉给予地塞米松（４ｍ ｇ／ｋｇ）， 再经腹腔注射戊四氮（３０ｍ ｇ／ｋｇ） 可明显减弱或完全抑制癫痫发作。免疫细胞化学双重染色证明， ＧＲ和ＧＡＢＡ共存于大脑皮质部分神经元。以上结果提示， 糖皮质激素具有抗慢性癫痫的效应， 其作用机制可能与ＧＲ调节同一神经元内ＧＡＢＡ的合成有关。

THE ANTI-EPILEPTIC EFFECT OF GLUCOCORTICOID AND ITS RELATION TO GABA

In order to explore the suppressive effect of glucocorticoid (GC) and its mechanism on chronically kindled epileptic rats, the behavior and EEG of the kindled rats induced by pentylenetetrazole were observed. The coexistence of glucorticoid receptor (GR) and GABA in the neurons of cerebral cortex was investigated by immunocytochemic double staining. The results showed that dexamethasone pretreatment (4mg/kg i.v.) at the day 3 or day 15 after kindling followed by injcetion of pentylenetetrazole (30mg/kg i.p) could reduce the degree of epileptic activity or suppress completely the epilepsy activity. Also, the coexistence of GR and GABA in a part of neurons of cerebral cortex was proved. The results suggest that GC could produce anti epileptic effect on the chonical epileptic rat by regulating synthesis of GABA in the same neurons of cerebral cortex.