Analytical Methodologies for the Characterization of Metabolites of Aromatic Amines in Fish

Abstract

The research staff from the Center for Lake Superior Environmental Studies (CLSES, University of Wisconsin-Superior) and the U.S. EPA Environmental Research Laboratory-Duluth (ERL-D) have developed and implemented a successful aquatic organism biotransformation research program. The efforts extended during the course of the cooperative agreement provided evidence of microsomal N-hydroxylation of primary aromatic amines by Japanese medaka and rainbow trout. The N-hydroxylation assay and metabolite analyses were developed at ERL-D through the cooperative efforts of UW-S/CLSES and U.S. EPA staff. The acquired data clearly provide evidence that trout and medaka form the proximate carcinogen, phenylhydroxylamine, from primary aromatic amines. This knowledge can be applied in support of the ongoing medaka carcinogenicity bioassays being performed at ERL-D because the known metabolic activation pathway (N-hydroxylation) for mammals has now been detected in fish. The following report includes an overview of the methods employed, results obtained over the past three years, and a discussion that incorporates relevant information obtained from the literature.