Metabolism of tributyltin and triphenyltin by Dall’s porpoise hepatic microsomes

The in vitro metabolism of tributyltin (TBT) and triphenyltin (TPT) by the hepatic microsomal cytochrome P-450 system enzymes of Dall's porpoises (Phocoenoides dalli) was comparatively elucidated with those enzymes of the Sprague Dawley rat in the present study. Our results suggested firstly a limited metabolic capacity for TBT and especially TPT to their metabolites in the Dall's porpoises, and documented a similar mechanism of a relatively stronger metabolic rate of TBT to its metabolites than that of TPT in the microsome of porpoises and rat. However, the metabolic capacity to degrade both TBT and TPT were much lower in the microsome of porpoises than that in the rats.