1,2‐dibromoethane and chloroform in the rainbow trout (Salmo Gairdneri): Studies on the distribution of nonvolatile and irreversibly bound metabolites

Abstract
The disposition of metabolites from 14C‐labeled 1,2‐dibromoethane (DBE) and chloroform (CF) in juvenile rainbow trout was studied by autoradiography and quantitation of tissue radioactivity. Whole‐body autoradiography of heated tissue sections showed a considerable level of nonvolatile metabolites of DBE and CF in the liver and certain areas of the body kidney. A lower level of metabolites appeared in the gills, intestinal mucosa, and olfactory rosettes in trouts exposed to DBE‐ or CF‐containing water. Unlike previous studies in rodents, no specific uptake or binding of DBE or CF occurred in the surface epithelia of the upper alimentary tract. Microautoradiography and exhaustive tissue extraction confirmed a high irreversible binding of DBE metabolites in the liver and in a proximal tubular segment of the body kidney in fish exposed to DBE‐containing water. A high level of radioactivity in the bile indicated fecal excretion of metabolites from both compounds. The results suggest that there is marked metabolism of DBE and CF in the liver and kidney, whereas the metabolism in the surface epithelia is low. The liver and kidney are proposed to be target organs of toxicity in fish.