Regulatory and scientific roles for biodistribution studies in aquatic species.

The advantage of focusing on biliary excretion of drugs and other xenobiotics is emphasized in this discussion of the regulatory and scientific roles for biodistribution studies in aquatic species. The role of the hepatobiliary system in the overall disposition of absorbed chemicals is briefly reviewed. The present survey includes 18 drugs, 6 petroleum hydrocarbons, and 16 different fish species. The fact that aquatic species concentrate most xenobiotics and their metabolites into bile to as much as several orders of magnitude underscores the advantage of using bile rather than tissue to determine whether aquatic species are being exposed to given chemicals. Until these advantages are recognized, analysis of edible muscle tissue remains the method of choice for assessment of human exposure to chemicals.