摘要
目的探讨牛磺酸(taurine,Tau)在甲基汞(methylmercury,MeHg)致大鼠脑谷氨酸代谢转运障碍中的作用。方法将健康清洁级Wistar大鼠24只按体重随机分为对照组、低剂量染汞组、高剂量染汞组和Tau干预组。每组6只,周一至周五每天进行染毒,即对照组腹腔注射浓度为0.9%的生理盐水,低剂量染汞组腹腔注射4μmol/kg MeHg,高剂量染汞组和Tau干预组腹腔注射12μmol/kg MeHg。每周一、三、五染毒前2 h进行干预,对照组、低剂量染汞组和高剂量染汞组皮下注射生理盐水,Tau干预组皮下注射1 mmol/kg的牛磺酸。连续进行4周,最后一次染毒后,处死大鼠,冷原子吸收法测定各组大鼠脑皮质汞含量,试剂盒测定谷氨酸(Glu)、谷氨酰胺(Gln)含量以及谷氨酰胺合成酶(GS)、谷氨酰胺酶(PAG)的活力,Fura-2/AM双波长荧光光度法测定细胞内钙离子浓度,流式细胞仪测定细胞凋亡率以及活性氧(ROS)的含量。结果随着染汞剂量的增大,脑皮质汞的含量亦升高,而Gln的含量降低,Glu的含量升高,GS的活力下降,PAG的活力增高,ROS的含量升高,细胞凋亡率增大;Tau预处理组与高剂量染汞组比较,各项指标均得到不同程度的改善。结论甲基汞可导致脑谷氨酸代谢障碍,Tau对其具有一定的防护作用。
Objective To explore the effect of taurine on metabolic and transport impediment of glutamate in the brain of rats induced by methylmercury （MeHg）.Methods Twenty-four Wistar rats of clean degree were randomly divided into control group,low-dose MeHg group,high-dose MeHg group and taurine intervention group by weight,each with 6 rats.The 4-week exposure was on a Monday-Friday basis.The rats in the control group was intraperitoneally injected with 0.9% NaCl,while the rats in low-dose MeHg group,high-dose MeHg group,and taurine intervention group were exposed to MeHg by intraperitoneal injection （4 μmol/kg,12 μmol/kg,and 12 μmol/kg,respectively）.Two hours before the exposure on every Monday,Wednesday and Friday,the rats in the control group,low-dose MeHg group and high-dose MeHg group were all subcutaneously injected with 0.9% NaCl,while the rats in the taurine intervention group were subcutaneously injected with 1 mmol/kg taurine.24 hours after the last exposure,all the rats were killed and the cerebral cortices were taken for detecting the contents of Hg by cold vapor atomic absorption spectroscopy.Glutamate （Glu） and glutamine （Gln） levels and the activities of glutamine synthetase （GS） and phosphate activated glutaminase （PAG） were determined by assay kits.Fura-2/AM double wavdength fluorescence determination was employed to measure the intracellular concentration of ionized calcium.Flow cytometric assay was used to detect apoptosis and reactive oxygen species （ROS）.Results The concentration of brain Hg in the cerebral cortex increased with the increasing exposure dose.Gln level and GS activity decreased,while Glu levd,PAG activity,ROS level and apoptosis rate increased.Compared with high-dose MeHg group,taurine intervention group showed varying degrees of antagonistic activity against neurotoxicity of MeHg.Conclusions MeHg can lead to metabolic and transport impediment of glutamate in the brain of rats and taurine has some protective effect against it.
出处
《实用预防医学》
CAS
2014年第3期261-263,共3页
Practical Preventive Medicine
基金
国家自然科学基金资助项目(81172631)
关键词
牛磺酸
甲基汞
谷氨酸代谢转运障碍
Taurine
Methylmercury
Metabolic and transport impediment of glutamate
