title: Effects of exogenous GSH and methionine on methylation of inorganic arsenic in mice exposed to arsenite through drinking water.
abstract: We hypothesized that chronic exposure to arsenic would deplete the reduced glutathione (GSH) and methionine in vivo, thereby impair the methylation capacity of inorganic arsenic (iAs) ingested. Our experiment was designed to explore the effects of exogenous GSH and methionine on arsenic methylation in mice exposed to arsenite via drinking water. Levels of iAs, monomethylarsenic acid (MMAs), and dimethylarsenic acid (DMAs) in the liver and blood were determined by the method of hydride generation coupled with atomic absorption spectrophotometry. Compared with mice exposed to arsenite alone, administration of GSH or methionine increased the secondary methylation index in the liver and primary methylation index in the blood, which resulted in the consequent increase of DMAs percent and decrease of iAs percent in the blood. Moreover, administration of GSH resulted in the increase of DMAs percent in the liver and total arsenic in the blood. Increase of total arsenic in the blood was mainly due to the increase of DMAs. Findings from the present study suggested that administration of GSH or methionine might potentiate the methylation capacity of arsenic in both liver and extrahepatic tissues, which may facilitate the excretion of arsenic and decrease arsenic related toxicities in the body.
authors.affiliation: Department of Environmental and Occupational Health, School of Public Health, China Medical University, Shenyang, Liaoning, People's Republic of China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Jin
authors.forename: Fenghong
authors.initials: F
authors.lastname: Zhao
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhong
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Yu
authors.forename: Di
authors.initials: D
authors.lastname: Sun
authors.forename: Yingjun
authors.initials: Y
authors.lastname: Liao
authors.forename: Xiuqiang
authors.initials: X
authors.lastname: Lv
authors.forename: Gexin
authors.initials: G
authors.lastname: Li
authors.forename: Guifan
authors.initials: G
authors.lastname: Sun
mesh_terms: D000818:Animals; D001151:Arsenic / Q000097:blood / Q000633:toxicity*; D020261:Arsenic Poisoning / Q000378:metabolism; D018053:Arsenites / Q000633:toxicity*; D002101:Cacodylic Acid / Q000378:metabolism; D004326:Drinking; D004781:Environmental Exposure; D005260:Female; D005978:Glutathione / Q000378:metabolism* / Q000494:pharmacology; D008099:Liver / Q000378:metabolism; D008715:Methionine / Q000378:metabolism* / Q000494:pharmacology; D008745:Methylation; D051379:Mice; D008815:Mice, Inbred Strains
chemical_list: D018053:Arsenites; D008715:Methionine; D002101:Cacodylic Acid; D005978:Glutathione; C015001:arsenite; D001151:Arsenic