Mercapturic acid formation and enzyme-catalyzed conjugations with glutathione in pigeons

Abstract

Pigeons are able to metabolize 3,4-dichloronitrobenzene (DCNB) and 2,3,5,6-tetrachloronitrobenzene (TCNB). The main metabolic route for DCNB is reduction of the nitro group and mercapturic acid is a minor metabolite. TCNB is converted to mercapturic acid. High-speed supernatant of pigeon liver contains enzymes which catalyze the conjugation of glutathione with DCNB and 2,4-dinitrochlorobenzene. Nitrite ions are enzymatically released from TCNB and 4-nitropyridine N-oxide during incubation with glutathione. Experiments with inhibitors are included.