Metabolism of arsenocholine in mice, rats and rabbits

The distribution, retention and biotransformation of arsenocholine, an organic arsenic compound present in certain seafood, have been studied in rats, mice and rabbits by use of synthesized 73 As-labelled arsenocholine. Orally administered arsenocholine was almost completely absorbed from the gastro-intestinal tract in mice and rats. In all species 70--80% of the administered dose was excreted in the urine within 3 days, [73 As] arsenobetaine was the main urinary metabolite; [73 As] arsenocholine was found in the urine of the first day only. No degradation to inorganic arsenic, mono- or dimethylarsenic acids, or trimethylarsine oxide was observed. In the tissues the 73 As activity retained was found in the form of [73 As] arsenobetaine and [73 As arsenophospholipids. Tissues with longest retention times were prostate, epididymis, testes, myocardium, liver, adrenal cortex, pancreas, dental pulp and pituitary gland.