title: Thio-dimethylarsinate is a common metabolite in urine samples from arsenic-exposed women in Bangladesh.
abstract: Over the last 6 years, much work on arsenic species in urine samples has been directed toward the determination of the reduced dimethylated arsenic species, DMA(III), because of its high toxicity and perceived key role in the metabolism of inorganic arsenic. Recent work, however, has suggested that DMA(III) may at times have been misidentified because its chromatographic properties can be similar to those of thio-dimethylarsinate (thio-DMA). We analyzed by HPLC-ICPMS (inductively coupled plasma mass spectrometry) urine samples from 75 arsenic-exposed women from Bangladesh with total arsenic concentrations ranging from 8 to 1034 microg As/L and found that thio-DMA was present in 44% of the samples at concentrations ranging mostly from trace amounts to 24 microg As/L (one sample contained 123 microg As/L). Cytotoxicity testing with HepG2 cells derived from human hepatocarcinoma indicated that thio-DMA was about 10-fold more cytotoxic than dimethylarsinate (DMA). The widespread occurrence of thio-DMA in urine from these arsenic-exposed women suggests that this arsenical may also be present in other urine samples and has so far escaped detection. The work highlights the need for analytical methods providing specific determinations of arsenic compounds in future studies on arsenic metabolism and toxicology.
authors.affiliation: Karl-Franzens University Graz, Institute of Chemistry-Analytical Chemistry, Universitaetsplatz 1, 8010 Graz, Austria.
authors.forename: Reingard
authors.initials: R
authors.lastname: Raml
authors.forename: Alice
authors.initials: A
authors.lastname: Rumpler
authors.forename: Walter
authors.initials: W
authors.lastname: Goessler
authors.forename: Marie
authors.initials: M
authors.lastname: Vahter
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ochi
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Francesconi
mesh_terms: D000328:Adult; D001151:Arsenic / Q000493:pharmacokinetics* / Q000652:urine; D001459:Bangladesh; D001711:Biotransformation; D002101:Cacodylic Acid / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000652:urine; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D011042:Poisons / Q000493:pharmacokinetics* / Q000652:urine; D011247:Pregnancy; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D007202:Indicators and Reagents; D011042:Poisons; C523062:thio-dimethylarsinate; D002101:Cacodylic Acid; D001151:Arsenic