Selenium and difluoromethylornithine additively inhibit DMH-induced distal colon tumor formation in rats fed a fiber-free diet.

摘要: We investigated the effects of difluoromethylornithine, an inhibitor ornithine decarboxylase (ODC) and selenium supplementation on tumor formation induced by carcinogen 1,2-dimethylhydrazine (DMH) in Sprague-Dawley rats. A biochemical link between polyamine biosynthesis metabolism to its cancer preventative form has been suggested common requirement S-adenosylmethionine. One-hundred twenty male rats were divided into experimental (n = 80) control 40) groups. Experimental animals received DMH 20 mg/kg s.c. for weeks. Animals fed either a regular diet (selenium content 0.2 p.p.m.) or high (5 with without 0.2% DFMO drinking water. At death, week 30, animal weights within groups not different four treatment Tumor number incidence proximal colon was affected treatment, combined treatment. In contrast, distal colon, 19 tumors developed treated group, 22 group only 12 selenium/DFMO compared 32 group. Similarly, decreased their additive. animals, ODC activity liver, but colon. tissue greater than normal from paired except colonic Polyamine content, however, did correlate neoplastic tissue. general, S-adenosylmethionine levels liver unaffected Selenium combination selectively inhibited fiber-free diet.