Effect Of Hydrogen Sulfide On Toxicity Of Methylmercury

In this study,sodium hydrosulfide（NaHS）,a donor of hydrogen sulfide（H₂S）,was used as the object of study.The effects of NaHS on the levels of mercury in tissues and oxidative damage in mice exposed to methylmercury chloride by injection,exposed to methylmercury chloride orally and NaHS by simultaneous administration,and exposed to methylmercury chloride followed by NaHS,to explore its effects on the accumulation of methylmercury and the repair of body damage,so as to provide a theoretical basis for the study of a new approach to the treatment of methylmercury poisoning.1.Effect of NaHS on tissue mercury and oxidative damag of mice injected methylmercuryMice were exposed to subcutaneous injection of methylmercury chloride,and administered to NaHS by gavage for 14 d,to explore the effects of NaHS as donor hydrogen sulfide on tissue mercury and oxidative damage in mice injected with methylmercury chloride.The results showed that compared with the mice exposed to methylmercury,hydrogen sulfide could increase the weight of mice,decrease the mercury content in liver,kidney and brain tissues,increase the activities of serum antioxidant enzymes SOD and GSH-Px,decrease the MDA content,and the serum ALT,AST,BUN and CREA decreased significantly.The effects of 5 mg/kg NaHS were more obvious than 1 mg/kg NaHS group.2.Effect of simultaneously administered NaHS on tissue mercury and oxidative damag in mice with orally adminstered methylmercuryMice were exposed to methyl mercuric chloride,and 1 h later fed with NaHS for14 d consecutive days to explore the effects of NaHS as donor hydrogen sulfide on tissue mercury content and oxidative damage in mice injected with methylmercury chloride.The results showed that the mercury content in tissues of 5 mg/kg NaHS group was significantly lower than that of methyl mercuric chloride poisoned group.The activities of serum antioxidant enzymes SOD and GSH-Px were Significantly increased,the content of MDA was significantly decreased,and the serum ALT,AST,BUN and CREA decreased significantly.The effect of 5 mg/kg NaHS group was better than that of 1 mg/kg NaHS group.Pathological sections assassy showed that 1 mg/kg and 5mg/kg NaHS could repair the pathological changes of liver,kidney and brain in mice in somewhat degrees,and 5 mg/kg NaHS had better repair effect than 1 mg/kg NaHS.3.Effect of NaHS on tissue mercury content and oxidative damag in mice after methylmercury exposureMice were administered with methyl mercury for continuous 7 d,and followed by administration of NaHS for 7 d or 14 d,to investigate the effects of NaHS on mercury and oxidative damage in tissues of mice exposed to methylmercury chloride after 7 and14 days of NaHS administration.The results showed that after 7 d of treatment,there was no significant difference in all indexes between the NaHS groups and the methyl mercury group.After 14 d of administration,there were no significant changes in the indexes of 1 mg/kg NaHS group.The mercury content in tissues of 5 mg/kg NaHS group was significantly lower than that of methyl mercury group,the activity of antioxidant enzymes was significantly increased compared to methyl mercury group,the content of MDA was significantly decreased,AST and ALT significantly decreased.BUN and CREA decreased significantly.Pathological sections showedno obvious pathological damage in liver,kidney and brain tissues of each group.In conclusion,NaHS has certain repair and improvement on toxic effects of methylmercury.