“…P450 gene has been described; the CYPIA1 from rainbow trout, Oncorhynchus mykiss (2,3). A detailed comparison of microsomal aniline hydroxylation in different tissues of rats (4), guinea pigs (4), rabbits (4,5), and sheep (6) was made; however, the toxicity of aniline or its derivatives has been determined for few fish species (7,8), and the biotransformation of these compounds were investigated previously (7)(8)(9)(10)(11)(12)(13). Aniline hydroxylation by cytochrome P450-dependent enzyme systems has been shown to be a possible way for metabolism in the liver of fish species, and the aniline hydroxylase is known to be a member of mixed-function oxidases catalyzing transformation of toxic aniline to nontoxic p-aminophenol.…”