RT Journal Article
SR Electronic
T1 DMPS-Arsenic Challenge Test. I: Increased Urinary Excretion of Monomethylarsonic Acid in Humans Given Dimercaptopropane Sulfonate
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 192
OP 200
VO 282
IS 1
A1 H. Vasken Aposhian
A1 Alex Arroyo
A1 Mariano E. Cebrian
A1 Luz María Del Razo
A1 Katherine M. Hurlbut
A1 Richard C. Dart
A1 Diego Gonzalez-Ramirez
A1 Helmut Kreppel
A1 Hernan Speisky
A1 Allan Smith
A1 Maria E. Gonsebatt
A1 Patricia Ostrosky-Wegman
A1 Mary M. Aposhian
YR 1997
UL http://jpet.aspetjournals.org/content/282/1/192.abstract
AB The purpose of the present study was to evaluate in a novel manner the arsenic exposure of humans living in two towns in Northeastern Chile. Residents of one town drink water containing 593 μg As/l. Those in the control town drink water containing 21 μg As/l. Our hypothesis was that the administration of the chelating agent, 2,3-dimercaptopropane-1-sulfonic acid, Na salt (DMPS, DIMAVAL) would increase the urinary excretion of arsenic, alter the urinary profile of arsenic species and thus result in a better indication of the body load of arsenic and a better biomarker for arsenic exposure. The method used to evaluate these subjects was to give them 300 mg DMPS by mouth, after an overnight fast, and collect urine at specified time periods. The urine samples were analyzed for inorganic arsenic, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and total arsenic by hydride generation and atomic absorption spectrophotometry. The results indicated that: 1) During the 2-hr period after DMPS administration, MMA represented 42%, inorganic As, 20 to 22% and DMA, 37 to 38% of the total urinary arsenic. The usual range of the MMA percentage in human urine has been 10 to 20%. The % MMA increased almost equally for both the arsenic-exposed and control subjects. 2) The exposed subjects had a greater urinary excretion of total arsenic, before and after DMPS administration, than the control subjects. 3) Although buccal cells were obtained only from a few subjects, the prevalence of mononucleated buccal cells, an indication of genotoxicity, was 5-fold greater for those who consumed drinking water with the higher arsenic content than among control subjects. Our conclusions are that 1) DMPS has a highly specific effect in humans on MMA metabolism and/or urinary excretion; 2) the human body stores substantial amounts of arsenic; and 3) the urinary arsenic concentration after DMPS administration may be more indicative of the body burden of arsenic because it was greater than that found before DMPS was given. The American Society for Pharmacology and Experimental Therapeutics