ABSTRACT
Chapter 3 in toxicology of fishes addresses the occurrence, regulation, and catalytic activities of biotransformation systems in fish and concludes with a focus on three model compounds and chemical classes and the contribution of biotransformation toward the toxicology of each compound. Biotransformation is a two-phase process catalyzed primarily through enzymatic reactions that often radically alter the chemistry of nonpolar lipophilic chemicals to polar water-soluble metabolites predominately leading to detoxification and elimination of the parent compounds. Unfortunately, the alteration of chemistry required for enhanced polarity often creates reactive intermediates through bioactivation, which can be more biologically hazardous than the initial parent compounds. This chapter provides a comprehensive update to what is known about phase I and phase II biotransformation enzymes in fish.
