摘要
目的研究致癫痫剂马桑内酯对大脑皮质神经元内游离钙（［Ｃａ２＋］ｉ）的作用及其作用途径，以探讨马桑内酯的致癫痫机制。方法利用培养１４天的大鼠大脑皮层神经元和ＡＲ－ＣＭ－ＭＩＣ阳离子检测系统，观察不同浓度的马桑内酯对［Ｃａ２＋］ｉ的作用，并分别用钙通道阻滞剂维拉帕米和２－氨基膦酸基戊酸（ＡＰ５）及钙螯合剂ＥＧＴＡ，观察马桑内酯作用的可能途径。结果马桑内酯使［Ｃａ２＋］ｉ水平升高，在（２５～５００）×１０－６ｍｏｌ／Ｌ范围内，呈明显的剂量效应关系；加入５×１０－３ｍｏｌ／ＬＥＧＴＡ至介质中后，马桑内酯作用消失，补充１０－３ｍｏｌ／Ｌ氯化钙后作用又出现；预先加入５×１０－６ｍｏｌ／Ｌ维拉帕米可明显拮抗其升钙作用，而加入１０－５ｍｏｌ／ＬＡＰ５则阻断作用不明显。结论致癫痫剂马桑内酯可使神经元内［Ｃａ２＋］ｉ升高，其升高［Ｃａ２＋］ｉ的作用依赖于细胞外钙，电压依赖性钙通道可能是其升高［Ｃａ２＋］ｉ的主要途径。
Objective To study the effect of coriaria lactone (CL) on cytosolic free calcium ([Ca 2+ ]i) of cultured neurons from the cerebral corteces in rats and also the main route of the effect, in order to explore the mechanism of epilepsy induced by CL in rats. Methods The primary neuron culture and the AR CM MIC cation measurement system were used. The typical pyramidal like neurons were cultured for 14 days were obtained and the effects of CL in different concentrations on [Ca 2+ ]i were observed. At the same time, the main route of CL effect was observed with loading ethyleneglyco bis (2 aminoethyl ether) tetraacetic acid (EGTA) and calcium channel blockers verapamil and 2 amino phosphino valeric acid (AP 5). Results The basic calcium of the cultured neurons was 0.994～1.034×10 -7 mol/L, the [Ca 2+ ]i was elevated by CL and the dose effect relationship was obvious in the concentration of 25～ 500× 10 -6 mol/L ( P <0.01). The effect disappear after loading 5×10 -3 mol/L EGTA, but it was found again after adding CaCl 2 to 10 -3 mol/L in the medium. The effect was blocked obviously by preloading with 5×10 -6 mol/L verapmil, but was not blocked in the presence of 10 -5 mol/L of AP 5. Conclusion The [Ca 2+ ]i of the cultured neurons was elevated with the convulsant CL. The effect of CL was dependent on extracellular calcium, while the voltage dependent calcium channel (VDCC) might be considered the main route of CL effect.
出处
《中华神经科杂志》
CAS
CSCD
1997年第5期291-293,共3页
Chinese Journal of Neurology
基金
国家自然科学基金
