甲醇吸入染毒对大鼠脑皮质氧化应激及皮质细胞凋亡的影响

Effects of Methanol Inhalation on Oxidative Stress and Apoptosis of Cortical Cells in Rats

目的观察甲醇对大鼠脑皮质神经细胞凋亡率的影响以及脑皮质氧化应激的改变,为进一步探讨甲醇神经毒性及其相关机制提供依据。方法选取体重为(200±20)g的健康SD大鼠80只,将其随机分为对照组,甲醇低、中及高剂量组,每组20只(甲醇质量浓度分别为0、25.344、50.688、101.376 g·m-3)。对照组大鼠吸入清洁空气,不同剂量甲醇组大鼠每天2h、连续28d静式吸入甲醇染毒。采用TUNEL法以及氧化应激试剂盒分别检测大鼠脑皮质神经细胞凋亡率和脑皮质中的谷胱甘肽过氧化物酶(GSH-PX)活力、丙二醛(MDA)含量、超氧化物酶(SOD)活力、谷胱甘肽(GSH)含量。结果实验期间,实验组大鼠活动减少,毛色缺乏光泽,反应缓慢,运动失调,染毒后期个别大鼠鼻孔出血,易激惹。高剂量组MDA的含量[(4.20±1.47)nmol·mg^(-1)]高于对照组[(2.65±1.00)nmol·mg^(-1)]与低剂量组[(2.86±0.91)nmol·mg^(-1)],高剂量组SOD活力[(97.70±34.41)U·mL^(-1)]低于对照组[(170.81±90.61)U·mL^(-1)]与低剂量组[(146.75±59.74)U·mL^(-1)],高剂量组的GSH含量[(17.48±3.76)μmol·L^(-1)]低于对照组[(26.22±10.61)μmol·L^(-1)]。与对照组相比,甲醇处理组各组大鼠脑皮质神经细胞的凋亡率增高(P=0.000),且随甲醇染毒剂量增加,神经细胞凋亡率也逐渐增加。结论甲醇高剂量暴露可引起大鼠脑组织发生氧化应激,导致细胞凋亡。

Objective To observe the effect of methanol on the apoptotic rate of rat cerebral cortical neurons and the changes of oxidative stress in the cerebral cortex,so as to provide evidence for further exploring the neurotoxicity of methanol and its related mechanisms.Methods Eighty healthy SD rats,weighing(200±20)g,were randomly divided into control group,low,medium and high dose groups of methanol,with 20 rats in each group(methanol concentration was 0,25.344,50.688,101.376 g·m^-3,respectively).Rats in control group were inhaled clean air.Rats in different doses of methanol group were exposed to methanol by static inhalation for 2 hours a day for 28 days.The apoptotic rate of neurons and the activity of glutathione peroxidase(GSH-PX),malondialdehyde(MDA),superoxide dismutase(SOD)and glutathione(GSH)in cerebral cortex of rats were detected by TUNEL and oxidative stress kit respectively.Results During the experimental period,the activity of the rats in the experimental group decreased,the color difference of the coat lacked luster,the reaction was slow,the movement was disordered,and the nostril bleeding of individual rats in the later period of exposure was prone to irritation.Compared with the control group[(2.65±1.00)nmol·mg^-1]and the low dose group[(2.86±0.91)nmol·mg^-1],the MDA content[(4.20±1.47)nmol·mg^-1]in the high methanol dose group increased,the SOD activity[(97.70±34.41)U·mL^-1]decreased.The GSH content[(17.48±3.76)μmol·L^-1]in the high methanol dose group was lower than the control group[(26.22±10.61)μmol·L^-1].Compared with the control group,the apoptotic rate of the cerebral cortical neurons in the rats in the methanol treatment group increased(P=0.000),and the apoptotic rate of neurons increased gradually with the increase of the dose of methanol.Conclusion The exposure of high dose methanol might induce oxidative stressand neurons apoptosis in rats.