The effects of sodium chloride, miso or ethanol on development of intestinal metaplasia after X-irradiation of the rat glandular stomach.

The influence of sodium chloride (NaCl), miso (Japanese soybean paste) and ethanol on development of intestinal metaplasia was examined. Five-week-old male CD(SD): Crj rats were treated with two 10 Gy doses of X-rays to the gastric region at a 3-day interval (total 20 Gy). After irradiation, the rats received supplementation with NaCl (1% or 10% in diet), miso (10% in diet) or ethanol (10% in drinking water) for 12 months. The number of alkaline phosphatase-positive foci of intestinal metaplasia in rats given 1% NaCl diet (Group 3) after X-rays was significantly elevated as compared to that in rats given X-rays alone (Group 1) (P < 0.01) or X-rays with 10% NaCl (Group 2) (P < 0.01). In the pyloric gland mucosae, the total numbers of metaplastic foci in rats of Group 3 were much higher than in Group 2, or after miso diet (Group 4) or ethanol supplementation (Group 5) (P < 0.01), but no difference was found between Group 2, 4 or 5 and Group 1. Atypical hyperplasia only appeared at incidences of less than 6% in Groups 1-3 and no promoting effect on gastric tumorigenesis was evident in Group 2. The present results thus showed that the occurrence of intestinal metaplasia induced by X-irradiation can be significantly increased by administration of 1% NaCl and decreased by 10% NaCl and ethanol, but this is not associated with any influence on gastric neoplasia.