Retention and Biotransformation of Arsenic Compounds Administered Intraperitoneally to Carp

Abstract

The arsenic metabolism in fish was examined using carp Cyprinus carpio and five arsenic compounds (arsenate, dimethylarsinate, arsenobetaine, trimethylarsine oxide, and arsenocholine). In order to avoid the bacterial action in the gut tract suggested previously, the arsenic compounds were administered to the fish not orally but intraperitoneally. Low retention of arsenic by the fish was observed after administration of arsenate, dimethylarsinate, or trimethylarsine oxide, while the arsenic administered as either arsenobetaine or arsenocholine was highly retained. After extraction and partial purification by Dowex 50 column chromatography, arsenic compounds accumulated in viscera and muscle were analyzed by HPLC-ICP/AES. As a result, arsenate and arsenocholine were found to be converted to arsenite and arsenobetaine, respectively, within the fish. Conversion of trimethylarsine oxide to another compound (probably dimethylarsinate) was also observed. In contrast, no biotransformation of dimethylarsinate and arsenobetaine occurred.