牛磺酸和维生素C对砷致小鼠小脑神经毒性保护作用

Effect of subchronic arsenic exposure on concentrations of cerebellar monoamine neurotransmitters and preventive roles of taurine and vitamin C in mice

目的观察砷对小鼠小脑单胺神经递质浓度影响,为探讨砷的神经毒作用机制提供依据。方法 70只昆明种小鼠,随机分为对照组、As2O31、2、4 mg/L染毒组及牛磺酸干预组(As2O34 mg/L+牛磺酸150 mg/kg和维生素C干预组(As2O34 mg/L+维生素C 45 mg/kg),每组10只(高剂量染砷组20只),连续染毒60 d,取小脑,用高效液相色谱法测小脑去甲肾上腺素(NE)、多巴胺(DA)和5-羟色胺(5-HT)浓度。结果对照组小鼠小脑NE、DA和5-HT浓度分别为188.96、45.30、148.42 ng/g;As2O31、2、4 mg/L染毒组小鼠小脑NE、DA和5-HT浓度分别为92.65、12.36、147.26 ng/g和37.18、9.44、105.0 ng/g及22.35、7.40、65.58 ng/g。染砷组小鼠小脑单胺类神经递质浓度明显低于对照组(P<0.05),牛磺酸和维生素C干预组小鼠小脑单胺类神经递质浓度,明显高于染砷组。结论牛磺酸和维生素C能拮抗砷致小鼠小脑5-HT、DA和NE浓度降低作用。

Objective To examine the effect of subchronic exposure to arsenic（As） on levels of three monoamine neurotransmitters in brains of mice and to provide evidences for exploring mechanism of As-induced neurotoxicity.Methods Seventy Kunming mice were randomly divided into one control group（drinking water alone）,three experimental groups（1,2 and 4 ppm As2O3）,and two protection groups（4 ppm As2O3＋150 mg/kg taurine and 4 ppm As2O3＋45 mg/kg vitamin C）.As2O3 was given through drinking water for 60 days.The mice were decapitated and their brains were removed.Three monoamine neurotransmitters,including onrepinephrine（NE）,dopanline（DA）,and 5-hydroxy tryptamine（5-HT） in cerebellum of mice were measured by high-performance liquid chromatography（HPLC） with fluorescence detector.Results The concentrations of NE,DA,and 5-HT were 188.96 ng/g,45.30 ng/g,and 148.42 ng/g in the mice cerebellum of control group.The concentrations of NE,DA,and 5-HT in mice cerebellum were 92.65,12.36 ng/g,and 147.26 ng/g and 37.18 ng/g,9.44 ng/g,and 105.00 ng/g7 and 22.35 ng/g,7.40 ng/g,and 65.58 ng/g,respectively,in the 1,2,and 4 ppm As2O3 groups.Levels of these neurotransmitters were significantly lower in the cerebellum of the mice exposed to As than those in the controls（P0.05）.On the contrary,the concentrations of NE,DA,and 5-HT were 30.76 ng/g,7.23 ng/g,and 77.88 ng/g and 37.75 ng/g,12.54 ng/g,and 61.41 ng/g in the taurine and Vit C group,being significantly higher than those of the group exposed to As（P0.05）.Conclusion Subchronic exposure to As can decrease the concentrations of 5-HT,DA,and NE in cerebellum of mice.Co-administration of taurine or Vit C may protect against the decreased concentrations of monoamine neurotransmitters induced by As.