Gastric cytoprotection in man by prostaglandin E2

In healthy volunteers, the effects of topical prostaglandins E2 (PGE2), 1 mg, on transmucosal potential difference (PD), mucus secretion, and epithelial cell turnover were investigated. PGE2 increased gastric PD by 10 mV on an average and stimulated mucus secretion of the stomach by 50%. In contrast, epithelial cell turnover remained unchanged. Gastric output of H+ decreased, whereas the outputs of volume, Na+, and Cl- rose in response to PGE2, which effects would be compatible with increased secretion of bicarbonate. Topical administration of ethanol 40% (vol/vol) reduced PD by 25 mV (delta PDE) and enhanced epithelial cell shedding by 350% with concomitant discharge of mucus from stomach epithelium. Pretreatment of the stomach with 1 mg PGE2 prevented the ethanol-dependent epithelial cell exfoliation, indicating gastric mucosal cytoprotection. Delta PDE and discharge of mucus were not significantly altered by PGE2. We conclude that gastric cytoprotection by PGE2 in man might be mediated by stimulation of mucus and/or bicarbonate production.