COMPARISONS OF UPTAKE AND DEPURATION OF 2-METHYLISOBORNEOL IN MALE, FEMALE, JUVENILE, AND 3MC-INDUCED CHANNEL CATFISH ICTALURUS-PUNCTATUS

The occurrence of off-flavors in farm-raised channel catfish is a majo r burden to the catfish culture industry, causing millions of dollars worth of market-ready fish to he rejected each year. Off-flavors are b elieved to be the result of exposure and subsequent accumulation of ce rtain volatile microbial metabolites such as 2-methylisoborneol. In th is study, the uptake and elimination of [C-14]-2-methylisoborneol equi valents were examined in juvenile and mature channel catfish. The desc ribed method is presented as a simple and inexpensive procedure for co mparing treatment effects on off-flavor elimination rates. In addition , the effects of the cytochrome P4501A inducing agent 3-methylcholanth rene on 2-methylisoborneol depuration was studied in juvenile fish. Up take was determined during a 24-h static exposure to waterborne 2-meth ylisoborneol (7.6 +/- 3.7 mu g/L). Uptake equilibrium had been establi shed in all groups by 12 h, with total uptake higher in juvenile fish. Depuration rates were not different between untreated groups (t(1/2) alpha = 12.4-22.4 h; t(1/2) beta = 91.3-143.7 h); however, the depurat ion half-lives for 3-methylcholanthrene treated juveniles were signifi cantly longer than those of controls.