Metabolism of tributyltin oxide by crabs, oysters and fish

Abstract

Bis(tributyltin) oxide (TBTO) is widely used as an antifouling agent in various antifouling paints. Thus, some marinas have TBTO concentrations as high as 2 μg/liter. 1 These concentrations can be toxic to zooplankton. 2 The objectives of the present study were to determine the ability of a number of marine animals, including crabs, oysters and fish, to metabolize TBTO. Earlier work showed that extracts of rat liver were able to metabolize TBTO to a variety of metabolites, e.g. β-hydroxybutyldibutylin. 3 The role of the cytochrome P-450 dependent mixed-function oxygenase system in oxidizing TBTO in marine animals was also of interest. Both in vivo (uptake of 14C-TBTO from food or water) and in vitro studies demonstrated that all the animals were able to metabolize TBTO. The oysters metabolized TBTO at a much slower rate than the other animals. The mixed-function oxygenase system from hepatic tissues of the various animals was able to metabolize TBTO by forming a number of hydroxylated metabolites.