The Effects Of Arsenic On Melanin Synthesis And NAC Intervention Of C57BL/6J Mice

Objective: 1. To observe the effects of arsenic on pathological characteristics of mice skin and to find pathological basis of arsenic-related skin lesions; 2. To study the effects of arsenic on melanin synthesis and NAC intervention of C57BL/6J mice, and to explore the potential biomarkers of chronic arsenic poisoning. Methods:50 female C57BL/6J mice were used for this study, which were divided into 5 group evenly on random. 1 was negative control group treated with free drinking tap water; 2, 3 and 4 were experiment groups treated with free drinking sodium arsenic of 50, 500, 5000μg/L; 5 was treated with free drinking sodium arsenic of 5000μg/L, after 30 days this group mice were given NAC(20mg/kg) by gavage once two days for 4 weeks, and keep free drinking sodium arsenic of 5000μg /L. The mice were taken blood and skin after they were treated with sodium arsenic for 60 days. The mice skin were taken HE staining and Dopa staining. The content of GSH, cysteine, TYR and melanin was measured. Results: 1. The general toxicity indicators of miceThe difference of mice weight of the infected group,control group and intervention group have no statistical significance(P>0.05); The heart, liver, spleen, lung, kidney viscera of all group coefficient difference is not significant(P>0.05).2. The pathological characteristics of mice skinThe positive rate of Dopa staining of control group is 71.43%, low dose group is 66.67%, middle dose group is 33.33%, high dose group is 33.33%, intervention group is 33.33%, coefficient difference is significant(P<0.05). 3. The TYR content of mice skinThe TYR content of mice skin in middle dose group, high dose group and intervention group is significantly lower than that of control group(P<0.05). 4. The cysteine content of mice blood and skinThe content of blood cysteine in low, middle, high dose group and the content of skin cysteine in low, middle, high dose group and intervention group is significantly lower than that of control group(P<0.05); Comparing with high dose group, the cysteine content of mice blood and skin in intervention group is significantly increasesd(P<0.05). 5. The GSH content of mice blood and skinThe GSH content of mice blood and skin in middle, high dose group is significantly lower than that of control group(P<0.05); Comparing with high dose group, the GSH content of mice blood and skin in intervention group is significantly increasesd(P<0.05). 6. The melanin content of mice blood and skinComparing with control group, the content of pheomelanin in low, middle, high dose group and intervention group is significantly decreasesd(P<0.05); the content of eumelanin and total melanin in middle dose group, high dose group and intervention group is significantly decreasesd(P<0.05); the ratio of pheomelanin/eumelanin in low, middle, high dose group and intervention group is significantly decreasesd(P<0.05). The content of pheomelanin and the ratio of pheomelanin/eumelanin in intervention group is significantly higher than that of high dose group(P<0.05). Conclusion: 1. The TYR content of mice skin can be effected by subchronic arsenic exposure; the content of TYR may be used as early potential biomarkers of arsenic poisoning. 2. The subchronic arsenic exposure have effects on non-protein SH of mice blood and skin, supplying sulfhydryl can elevate the level of non-protein SH. 3. The subchronic arsenic exposure can produce effects on melanin synthesis of mice skin, pheomelanin increased after supplying sulfhydryl, so sulfhydryl compounds may be used to treat arsenic-related skin pigmentation disorder.