牛磺酸对甲基汞致大鼠脑氧化损伤的保护作用
Protective Effects of Taurine on Methylmercury-Induced Oxidative Damage
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摘要:
目的 探讨甲基汞致大鼠脑氧化损伤及牛磺酸对氧化损伤的保护作用。 方法 将24只健康清洁级Wistar大鼠按体质量随机分为4组,每组6只,分别为对照组、低剂量染汞组、高剂量染汞组和牛磺酸干预组。周一至周五每天进行染毒,对照组腹腔注射生理盐水,低剂量染汞组腹腔注射4 μmol/kg氯化甲基汞,高剂量染汞组和牛磺酸干预组腹腔注射12 μmol/kg氯化甲基汞;每周一、三、五染毒前2 h进行预处理,对照组、低剂量染汞组和高剂量染汞组皮下注射生理盐水,牛磺酸干预组皮下注射1 mmol/kg的牛磺酸;连续进行4周,最后一次染毒后,处死大鼠。取大脑皮质测定:活性氧(ROS)、巯基、羰基、丙二醛(MDA)的含量,超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-px)的活性及细胞凋亡率。 结果 与对照组比较,低、高汞组大鼠的体质量增长幅度降低(P<0.05, P<0.01); ROS分别是其1.8和3.9倍(均P<0.01); SOD和GSH-px的活性均降低;巯基的含量降低;羰基的含量升高; MDA增加;细胞凋亡率分别升高3.4和10.0倍。牛磺酸干预组与高剂量染汞组比较, ROS的生成量降低了17%; SOD、GSH-px的活性有不同程度的升高;巯基、羰基和MDA的含量也有不同程度的改变;细胞凋亡率为高汞组的44%。 结论 甲基汞可导致脑氧化损伤,牛磺酸对甲基汞所致氧化损伤具有一定的保护作用。 Abstract:Objective To examine the effects of methylmercury on oxidative damage in cerebrum of rats and the protective effects of taurine on the oxidative damage. Methods Twenty-four rats were randomly divided into four groups by weight:control (saline), low methylmercury (4 μmol/kg), high methylmercury (12 μmol/kg), and taurine intervention groups (4 μmol/kg methylmercury + 1 mmol/kg taurine). Exposure started from Monday to Friday by intraperitoneal injection and lasted four weeks. Two hours before the exposure on every Monday, Wednesday, and Friday, the control, low methylmercury, and high methylmercury groups were subcutaneously injected with 0.9% sodium chloride, and the taurine group was subcutaneously injected with 1 mmol/kg taurine. Twenty-four hours after the last exposure, the rats were neutralized, and the cerebral cortices were taken for detecting contents of reactive oxygen species (ROS), sulfydryl, carbonyl, malondialdehyde (MDA), activities of super oxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and apoptosis rate. Results The body weights of animals increased less in the low and the high methylmercury group (P<0.05 and P<0.01) respectively than that in the control group. The contents of ROS in the low and the high methylmercury groups were 1.8 and 3.9 times respectively of the control group (both P<0.01); the activities of SOD and GSH-Px decreased, the contents of sulfydryl decreased, the contents of carbonyl and MDA increased, and the apoptosis rates increased 3.4 and 10.0 times respectively. Compared with the high methylmercury group, the content of ROS of the taurine group reduced by17%, the activities of SOD and GSH-Px increased, the content of sulfydryl, carbonyl, and MDA also changed, and the apoptosis rate was 44% of reported in the high methylmercury group. Conclusion Methylmercury can lead to oxidative damages in rat cerebral cortices, and taurine shows protective effects on methylmercury-induced oxidative damages.
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