Uptake, distribution, and elimination of dietary quinoline by rainbow trout (Salmo gairdneri)

1. Rainbow trout (Salmo gairdneri) readily absorbed 14C-quinoline from pelleted food and whole-body concentrations reached apparent equilibrium after 10 days feeding. Maximum whole body concentrations of 14C-quinoline were only 30 eta g/g of quinoline plus metabolites after 7 days depuration. 2. Initial rates of uptake and elimination varied widely among tissues. The uptake rate constants ranged from 0.0006/day for muscle to 0.1455/day for gallbladder plus bile. Mean elimination half-life for quinoline and its metabolites ranged from 0.4 days in gills to 8.7 days for muscle. 3. Depending on tissue, 58-83% of the stored radioactivity was present as metabolites. About 14% of the radioactivity in the bile was present as glucuronide conjugates. 4. Rainbow trout eliminated 66% of the ingested dose 24 hr after feeding. Biliary and fecal excretion were minor routes of elimination.