中文摘要：

目的探讨同型半胱氨酸（homocysteine,Hcy）对饮水砷暴露小鼠尿中各形态砷及血中谷胱甘肽（GSH）和总抗氧化能力（T-AOC）的影响。方法将健康清洁级的雌性昆明小鼠18只,随机分为对照组、单纯染砷组及Hcy与砷联合的染砷干预组,每组6只。除对照组小鼠饮蒸馏水外,另外2组小鼠以自由饮水方式饮含50 mg/L亚砷酸钠的水,染毒10 d。在染毒的第10天,将所有小鼠放置代谢笼中,同时染砷干预组小鼠腹腔注射200 mg/kg体重的Hcy溶液,对照组和单纯染砷组小鼠腹腔注射生理盐水,早晚各1次。首次注射24 h后,收集尿液,然后处死小鼠,快速取血,检测血中GSH和T-AOC,然后检测尿中无机砷（iAs）、一甲基胂酸（MMA）和二甲基胂酸（DMA）含量,并计算总砷含量（TAs）及一甲基化率（primary methylation ratio,PMR）和二甲基化率（secondary methylation ratio,SMR）。结果单纯染砷组和染砷干预组小鼠尿中iAs、MMA、DMA、TAs及MMA%均高于对照组,而DMA%和SMR低于对照组,且差异有统计学意义（P〈0.05）。染砷干预组小鼠尿中iAs、DMA、TAs及SMR均显著高于单纯染砷组而MMA%显著低于单纯染砷组（P〈0.05）。与对照组相比单纯染砷组和染砷干预组小鼠全血GSH显著降低（P〈0.05）。与对照组和染砷干预组相比,单纯染砷组小鼠血清T-AOC均显著降低（P〈0.05）。结论暂时性Hcy升高能增加小鼠砷甲基化能力,加强砷代谢产物的排泄,从而降低砷对机体的损害。

英文摘要：

Objective To explore effect of homocysteine（HCY） on urine arsenic metabolism and glutathione （GSH） and total antioxidant capacity （ T - AOC） in blood of mice. Methods Eighteen female Kunming mice were randomly divided into control group, arsenic exposure group and arsenic exposure with HCY group, six mice in each group. The mice in the experimental groups were exposed to sodium arsenite through drinking water with 50 mg/L arsenic for ten days. On the tenth day, all mice were put into metabolic cage. The control group and arsenic exposure group were treated intraperitoneally one time in the morning and evening with saline solution, arsenic exposure with HCY group were treated intraperitoneally with 200 mg/kg homocysteines. The first twenty - four hours after intraperitoneal injection, urine and blood samples were collected immediately for arsenic species and the GSH and T - AOC analysis. Levels of of inorganic arsenic in urine, monomethylated arsenic （MMA） and dimenthylated arsenic （DMA） were detected. Then total arsenic speciation （TAs）, primary methylation ratio （PMR） and secondary methylation ratio （SMR） in urinary were calculated. Results Compared with the control group, the levels of iAs, MMA, DMA and TAs and the MMA% of arsenic exposure group and arsenic exposure with HCY group were significantly higher, but the DMA% and SMR were lower in the two groups （ P 〈 0.05 ） ; The levels of iAs, DMA , TAs and SMR in the arsenic exposure with HCY group were much lower than that of arsenic exposure group （ P 〈 0.05） ; Compared with the control group, GSH contents in other groups were significantly lower（ P 〈0.05） ; Compared with control group and arsenic exposure with HCY group, T-AOC of serum in the arsenic exposure group were significantly decreased （ P 〈 0.05）. Conclusion The temporary rise of HCY can enhance arsenic methylation in mice and excretion promoting of methylated arsenic could reduce the body damage from arsenic.