|Budget Amount *help
¥2,500,000 (Direct Cost : ¥2,500,000)
Fiscal Year 1999 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Fiscal Year 1998 : ¥1,300,000 (Direct Cost : ¥1,300,000)
A high frequency of esophageal cancer of heavy drinkers has been confirmed from epidemiological studies. However, details of the mechanisms causing this high frequency have not yet been clarified. Human beings are exposed nitrosamines, which is a procarcinogen, during their lifetime. N-nitrosmethylbenzylamine (NMBA), one of nitrosamines, causes esophageal cancer. Recently, it has become clear that cytochrome P4502E1 (CYP2E1) is induced by ethanol and metabolizes NMBA.The induction of CYP2E1 by ethanol is occurred in esophagus as well as liver and other organs. In this study, we analyzed the effect of ethanol on the development of esophageal cancer in rats treated with NMBA.Methods : Twenty Wister male rats were divided into two groups (ethanol and control) according to the liquid diets they were fed. Ethanol group was given an ethanol-containing liquid diet (36% of total calories), and control group was pair-fed with a control diet where ethanol was replaced isocalorically with carbohydrate for 2 weeks. After preliminary feeding, 0.1 mg/kg body weigh/day of NMBA was administered intraperitoneally twice a week for 10 weeks with liquid diets. After 30 weeks treatment, rats were killed. Results : Five to eight visible papillomas were found in esophagus of all ethanol treated rats, while only one papilloma was found five of the ten control rats. In esophageal epithelium in ethanol treated rats, CYP2E1 was stained strongly, but it was not stained in control rats. Conclusions : These results suggest that alcohol may promote the development of esophageal cancer in rats.