2-AMINO-3-METHYLIMIDAZO[4,5-F]QUINOLINE (IQ), A CARCINOGENIC PYROLYSATE, INDUCES CHROMOSOMAL-ABERRATIONS IN CHINESE-HAMSTER LUNG FIBROBLASTS IN-VITRO

The ability of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) to induce chromosomal aberrations (CAs) in Chinese hamster lung fibroblast (CHL/ IU) cells in vitro was examined. On incubation with rat S9 (2.5 - 10%, v/v) for 3 h, followed by a recovery culture period of 21 h, IQ cause d significant induction of CAs at a concentration 20 mug/ml, but had l ess effect at 40 mug/ml. With longer recovery culture times such as 27 -33 h, however, IQ was much more effective at 40 mug/ml. No significan t induction was observed with 1 or 6 h treatments followed by 23 or 18 h recovery cultures, respectively. On incubation without S9, only wea k CA induction by IQ was observed. These results show that IQ is a cla stogen and that its clastogenic effect varied with the experimental co nditions, such as the time of exposure and the time of recovery cultur e. The cell cycle perturbation effect is suggested to be one of the cr itical factors for the detection of the clastogenic potential of IQ.