Gastric Cytoprotection in Man by Prostaglandin E₂

Abstract

In healthy volunteers, the effects of topical prostaglandin 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 CI^- 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 (ΔPD_E) 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. ΔPD_E 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.

Key-words:

• Cytoprotection
• epithelial cell desquamation
• potential difference
• prostaglandin E₂
• stomach