2,5-己二酮对运动神经元钙稳态的影响

目的 研究正己烷代谢产物2,5-己二酮对运动神经元钙稳态的影响,探讨正己烷中毒致周围神经损伤的机制.方法 对运动神经元细胞系VSC4.1细胞不同浓度的2,5-己二酮体外染毒,用四甲基偶氮唑蓝（MTT）法检测细胞活性的变化;同时检测Ca^2＋-Mg^2＋ATP酶和Na^＋-K^＋-ATP酶活力.以Fluo-3/AM为荧光指示剂,激光共聚焦方法检测细胞内游离钙浓度的瞬时变化状况;用流式细胞仪检测细胞内钙平均浓度的变化.结果 经2.5、5.0、7.5、10.0、15.0、20.0 mmol/L浓度的2,5-己二酮对VSC4.1细胞染毒后与对照组比较,Ca^2＋-Mg^2＋ATP酶和Na^＋-K^＋-ATP酶的活力均下降.33.5 mmol/L的2,5-己二酮可在10 s内引起VSC4.1运动神经元细胞内钙浓度升高,40s后恢复到基线水平.VSC细胞与2,5-己二酮接触后即刻引起细胞内钙水平的增加,10 min后达到最高.结论 2,5-己二酮可能通过干扰细胞钙稳态产生神经毒性.

Effect of 2,5 - hexanedione on calcium homeostasis of motor neuron

Objective To explore the mechanism of cytotoxic effect of 2,5-hexanedione(2,5-HD) on motor neuron. Methods Vsc4.1(a cell line from motor neuron) was incubated with a series concentration of 2,5-HD. The cell viability, Ca2+ Mg2+ ATPase and Na + K + ATPase were detected. Laser scanning confocal microscope (LSCM) was used for detecting intracellular calcium level. The average calcium level in VSC4.1 was measured by flow cytometry. Results The cell viability was decreased when Vsc4.1 cells were treated with 2,5-HD at the dosage of 2.5,5.0,7.5,10,15 and 20 mmol/L for 24 hours. Compared with the control group the activity of Ca2+ Mg2+ ATPase was decreased to 70.02% ,77 .44% and 47.47% respectively;the activity of Na+ K+ ATPase was decreased to 82.07 % , 72.45 % and 50.71 % . The difference was significant. Intracellular free calcium of VSC4.1 cell was increased rapidly within 10 s and then recovered within 40 seconds when it was exposed to 33 .5 mmol/L 2,5-HD. An increase in intracellular calcium was observed when the VSC4.1 was treated with 33.5 mmol/L 2,5-HD . The peak of intracellular calcium level occurred ten minutes later. Conclusion The disturbance of calcium homeostasis may be involved in the mechanisms of neurotoxicity of 2,5-HD.