Xenobiotic metabolizing enzyme systems in test fish. III. Comparative studies of liver cytosolic glutathione S-transferases.

The reduced glutathione (GSH)-conjugating capacities of the livers of trout, carp, zebra fish, guppy, and bluegill have been evaluated with several substrates preferentially metabolized by the major GSH-transferase isozymes. Carp and zebra fish lack GSH-transferase activity with 1,2-epoxy-3-(p-nitrophenoxy)propane. Guppy is characterized by the highest activities with 1-chloro-2,4-dinitrobenzene and the absence of activity toward trans-4-phenyl-3-buten-2-one. Enzyme activities with the other substrates demonstrate quantitative interspecific differences which presumably are of minor relevance to the metabolism and toxicity of chemicals.