Cellular metabolism of arsenocholine.

The biotransformation of arsenocholine and arsenobetaine, which are organic arsenic compounds present in certain aquatic organisms, has been studied in vitro using synthetic reference substances. Incubation of arsenocholine with different liver cell fractions showed arsenocholine to be biotransformed only in presence of the mitochondrial fraction. The biotransformation products were arsenobetaine aldehyde, arsenobetaine, trimethylarsine oxide and trimethylarsine. Arsenobetaine was the major metabolite and it was formed via arsenobetaine aldehyde. Trimethylarsine oxide was formed via a side reaction from arsenobetaine aldehyde. Further reduction of trimethylarsine oxide, produced trimethylarsine. In vitro studies of arsenobetaine, did not show any formation of trimethylarsine oxide or trimethylarsine. Furthermore, cytotoxicity of arsenobetaine or arsenocholine in isolated hepatocytes was not observed.