马桑内酯对大鼠大脑皮层突触体和脑片谷氨酸摄取、释放功能的影响

Effect of cortaria lactone on glutamate release of brain slices and glutamate uptake of synaptosomes

目的：研究致痫剂马桑内酯对谷氨酸摄取和释放功能的影响，以探讨马桑内酯致痫的可能机制。方法：放射性同位素分析技术。结果：在０．３５～３５０μｍｏｌ·Ｌ－１浓度范围内，马桑内酯使高钾（５０ｍｍｏｌ·Ｌ－１）去极化引起的脑片谷氨酸释放增加，增加率为１１．２％～３３．２％，剂量效应关系明显，３５μｍｏｌ·Ｌ－１和３５０μｍｏｌ·Ｌ－１组与对照组相比谷氨酸释放显著增加（Ｐ＜０．０１），各浓度马桑内酯对静息态谷氨酸基础释放均无明显作用。在３５０μｍｏｌ·Ｌ－１马桑内酯作用下，突触体谷氨酸摄取降低，降低率为７．９４％，与对照组差异显著（Ｐ＜０．０５），其它浓度马桑内酯作用不明显。结论：马桑内酯使谷氨酸释放增加，摄取减少，突触间隙谷氨酸聚积。

OBJECTIVE:To explore the mechanism of epilepsy evoked by coriaria lactone (CL),we studied the effects of CL on glutamate(Glu) release and uptake.METHOD:Radioisotope technique.RESULTS:CL(0.35～350 μmol·L -1 ) enhanced the Glu release from the cerebral slies in the depolarization evoked by 50 mmol·L -1 KCl.The increase rates were 11.2%,16.7%,27.4%,33.2% respectively.The relationship of dose and effect was obvious,but no effect was observed in the rest state.The Glu uptake of synaptosomes was decreased by CL in the concentration of 350 μmol·L -1 ,with a decrease rate of 7.96%,but no effect was observed in other concentrations.CONCLUSION:CL enhanced Glu release in the depolarizing state and decreased Glu uptake.