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.