Uptake and biotransformation of quinoline by rainbow trout

Rainbow trout ( Salmo gairdneri) readily absorb and metabolize [ 14C]quinoline when exposed to 1 mg/1 concentration in water. Juvenile fish accumulated over 60% of the total radiolabel body burden in the gall bladder as quinoline metabolites after 48 h exposure followed by 24 h in clean water. Hydrolysis products of the metabolites, isolated by alkaline digestion and base-catalysed acetylation, were found to be hydroxyquinolines and quinolinethiols. There is evidence that the hydroxy form was present in the gall bladders as the glucuronide was obtained from thin layer chromatographic experiments, and by cleavage with β-glucuronidase. The thiols, identified by high and low resolution mass spectrometry, predominated over the hydroxy derivative in most tissues examined. Relative body burdens of quinoline plus metabolites after 48 h were in the order gall bladder > muscle > gut > eyes > liver ≅ gill ≅ kidney.