高钾可诱导培养的小脑颗粒神经元凋亡

Apoptosis of cultured cerebellar granule neurons of the rat induced by high potassium

采用四唑盐比色、琼脂糖凝胶电泳、乙二酸荧光素染色和Hoechst332 58染色等方法研究高钾对原代培养的大鼠小脑颗粒神经元的毒性作用及其机制。结果发现 :①高钾诱导神经元死亡呈剂量 ( 50～ 10 0mmol/L)和时间依赖性 ;②神经元死亡呈现明显的凋亡特征 :胞体缩小 ,染色质浓缩 ,DNA“梯形”条带形成和蛋白质合成抑制剂 (cycloheximide ,1.0mg/L)可阻断其毒性等 ;③MK 80 1( 2 μmol/L)、尼莫地平 ( 10 μmol/L)、硫酸镁 ( 2 0mmol/L)可阻断高钾的大部分毒性作用。结果提示

With MTT method, agarose gel electrophoresis, FDA staining and Hoechst 33258 staining,we studied the toxicity of high potassium against primary cultured cerebellar granule neurons and its mechanism. The results showed that:①high potassium induced neuronal death in a concentration (50～100 mmol/L) and time dependent fashion; ②the neuronal death induced by high potassium displayed the characteristics of apoptosis, including the shrinkage of cell bodies, nuclear condensation, DNA fragmentation and its toxicity attenuation by the supplement of cycloheximide(1.0 mg/L), an inhibitor of protein synthesis.③MK 801(2 μmol/L),nimodipine(10 μmol/L)and magne sium sulfate (20 mmol/L) were able to inhibit the toxicity of high potassium against neurons. These findings suggest that high potassium induced the apoptosis of cerebellar granule neurons probably by stimulating endogenous glutamate release.