Release of protective products, different from prostaglandins, by rat stomachs exposed to mild irritant.

The factors responsible for the mediation of mild irritant-induced (adaptive) cytoprotection to the rat stomach are not fully understood. The existence of cytoprotective products that are released by the gastric mucosa in response to its exposure to a mild irritant is assessed in this work. Gastric contents of rats exposed to a mild irritant (0.3 N HCl) or to 0.3 N NaCl (control) were collected, titrated to neutrality, and administered orally to prefasted animals followed by 100% ethanol. Ethanol-induced gross hemorrhagic injury in rats pretreated with the 0.3 N HCl gastric contents were significantly less than in control treated rats (P less than 0.01). Pretreating the donor or recipient rats with indomethacin did not interfere with the generation or protective action of the 0.3 N HCl gastric contents. These findings demonstrate that the exposure of the gastric mucosa to a mild irritant causes the release of protective products, which are different from prostaglandins, into the gastric lumen.