Effects of 4-week treatment with gastric carcinogens and enhancing agents on proliferation of gastric mucosa cells in rats.

Catechol and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) are gastric carcinogens in rats. Catechol, sodium chloride and bile salts have enhancing effects on gastric carcinogenesis induced by MNNG in rats. The effects of these compounds on proliferation of pyloric mucosa cells in male F344 rats were examined immunohistochemically using bromodeoxyuridine (BrdU) and anti-BrdU monoclonal antibody. Rats were given MNNG (83 micrograms/ml in their drinking water), catechol (0.8% in their diet), sodium taurocholate (0.3% in their diet), sodium taurodeoxycholate (0.3% in their diet), or sodium chloride (10% in their diet or by intragastric administration of 1 ml of saturated solution once a week) for 4 weeks. All these treatments markedly enhanced cell proliferation of the pyloric epithelium, suggesting the importance of enhanced cell proliferation in the development of gastric cancer.