Individual Variability in the Human Metabolism of an Arsenic-Containing Carbohydrate, 2′,3′-Dihydroxypropyl 5-deoxy-5-dimethylarsinoyl-β-D-riboside, a Naturally Occurring Arsenical in Seafood

We report studies oil the variability in human metabolism of all oxo-arsenosugar involving the Ingestion of a chemically synthesized arsenosugar and quantitative determination of the arsenic metabolites ill urine and serum by HPLC coupled with arsenic-selective mass spectrometric detection (IONS, inductively coupled plasma mass spectrometry). The total, four-day, urinary excretion of arsenic Six Volunteers ranged widely from ca. 4-95%. The arsenic metabolites present in the urine also showed great variability: high arsenic excretion was accompanied by almost complete biotransformation of the ingested oxoarsenosugar into a multitude of metabolites (> 10), whereas the subjects that excreted low amounts of arsenic produced low quantities of metabolites relative to unchanged oxoarsenosugar and its thio-analogue Major arsenic urinary metabolites were dimethylarsinate (DMA) and possible intermediates ill the degradation of arsenosugar to DMA, namely, dimethylarsinoylethanol (DMAE) and dimethylarsinoylacetate (DMAA) present both as their oxo- and thio-analogues. Thio-DMAE and thio-DMAA were also found in blood serum indicating that these species were formed in the liver rather than Oil storage of the Urine in the bladder. The large variability in the way individuals metabolize arsenosugars has implications for risk assessment of arsenic intake from seafood.