Abstract: To investigate the suppressive effects of retinoic acid (RA) on the hepatocar cinoma induced by N-diethylnitroamine (DENA) in rats. RA (1.5mg/kg, treated group) and the saline without RA (control group) were administrated (i.p) every other day to the rats of hepatocarcinogenesis induced by DENA beginning from the 11th week. At the beginning of the 16th week, 7 rats in each group were killed. The nodules ≥3mm and ≥5mm in diameter and the volume of the largest nodule were calculated and compared among groups. The survival time was recorded and the rats were weight ed before and after the administration. The number of the nodules ≥3mm and ≥5mm in treated group were significantly less than those in control group (P<0.05). The mean volume of the largest nodule in treated group was significantly smaller than in con trol group (P<0. 05). Compared with control group, the survival time in treated group prolonged by 55.8% , but the bodyweights of rats in treated group did not changed. The results indicated that RA suppressed the development of primary hepatic nodules in duced by DENA and prolonged the survival time of the rats.

Key words: Retinoic acid , Side effect , Primary hepatocarcinoma