Abstract
Modifying effects of KYN-54, a newly synthesized retinoidal butenolide, were investigated on 2-amino- 3-methylimidazo [4, 5-ƒ] quinoline (IQ)-induced carcinogenesis in rats. One hundred and twenty male F344 rats were divided into 4 groups. Starting at 5 weeks of age, rats were fed the basal diet (Groups I and 4) or the experimental diet (0.02% KYN-54) (Groups 2 and 3). At 7 weeks of age, Groups I and 2 were given IQ (0.35m mol/kg body weight, once weekly for 12 weeks) by a intragastric tube. One week after the final IQ intubation, the experimental diet for Group 2 was switched to basal diet. Group 4 was treated as the vehicle control. All rats were sacrificed at the termination (48 weeks after the start of experiment) and 5 rats from each group, which were sacrificed at 12 and 24 weeks. At the termination, sporadic tumors were recognized only in Group I (IQ alone) and Group 2 (IQ+ KYN-54). But no significant differences for each tumor were available between the 2 groups. Furthermore, no statistical differences were recognized for the incidences of aberrant crypt foci in the 2 groups. However, the density of enzyme altered foci of Group 2 was significantly smaller than of Group I (3.21±4.49/cm2 vs. 10.71±9.76/cm2, P<0.05). These results imply that the synthesized butenolide compound has a weakly inhibitory effect on hepatocarcinogenesis in rats.
