敌百虫对体外培养大鼠大脑皮质神经细胞凋亡的影响

Effect of trichlorfon on cultured rat cerebral cortical neurons apoptosis

为探讨敌百虫对大鼠大脑皮质神经细胞的毒性作用及机理,本研究在建立体外培养新生24h内SD大鼠大脑皮质神经细胞模型的基础上,在细胞培养液中添加0、5、20、80mg/L敌百虫染毒,在染毒后的不同时间测定细胞凋亡率、线粒体膜电位、细胞内[Ca2+]i、ROS含量和ATP酶的变化。结果显示:①染毒12h,细胞凋亡率明显增加;②染毒12h,各染毒组线粒体膜电位逐渐降低,其中80mg/L组与对照组存在极显著差异(P<0.01);③染毒0.5h,各染毒组细胞内[Ca2+]i显著高于对照组(P<0.01);染毒12h,各染毒组细胞内[Ca2+]i呈下降趋势,但仍显著或极显著高于对照组(P<0.05或P<0.01);④染毒12h和24h,细胞内ROS水平显著或极显著高于对照组(P<0.05或P<0.01);⑤染毒12h,细胞Na+-K+-ATPase和Ca2+-Mg2+-ATPase活性逐渐降低,20、80mg/L组与对照组有极显著差异(P<0.01);上述指标的变化呈显著的剂量-效应关系。结果表明,低质量浓度敌百虫暴露可致大鼠大脑皮质神经细胞凋亡率和细胞内ROS含量升高,线粒体膜电位下降,细胞内钙离子超载且ATPase活性降低,提示细胞凋亡在敌百虫所致的大脑皮质神经细胞损伤过程中发挥主导作用。

To investigate the effect and mechanism of low concentration of trichlorfon on rat cortical neuron,based on established the model of cortical neuron cultured in vitro which were obtained from the neonate Sprague-Dawley rats within 24 h,the cell culture medium was exposured with trichlorfon of 0、5、20、80 mg/L,and then at different times,apoptosis rate,mitochondrial membrane potential,i,content of ROS intra-cellular and activities of ATPase were measured.The results were as follows：①Neurons treated by different concentrations of trichlorfon for 12 h,increased the apoptosis rate significantly.②Neuron＇s mitochondrial membrane potential descended with different concentrations of trichlorfon after culturing 12 h.And the 80mg/L group significantly decreased,compared with the control group（P0.01）.③Exposured with trichlorfon for 0.5 h,neuron＇s i intra-cellular of exposure groups was increased significantly compared with the control group（P0.01）;Exposured with trichlorfon for 12 h,neuron＇s i intra-cellular of exposured groups was decreased,but significantly higher than the control group（P0.05 or P0.01）.④Exposured with trichlorfon for 12 h and 24 h,intracellular ROS levels were significantly higher than the control group（P0.05 or P0.01）.⑤Exposured with trichlorfon for 12 h,the activities of neuron＇s Na＋-K＋-ATPase and Ca2＋-Mg2＋-ATPase were decreased.And compared with the control group,20 mg/L and 80 mg/L groups were very significantly decreased（P0.01）.The indicators showed significant changes in dose-effect relationship.The results showed that exposured with different concentrations of trichlorfon can cause apoptosis and intracellular ROS increased,mitochondrial membrane potential decreased,may the intracellular calcium overloaded and ATPase activity decreased.It prompted that the apoptosis play a leading role in the trichlorfon-induced injury of rat cerebral cortical neurons.