Influence of gender difference and gastritis on gastric ulcer formation in rats

Background: Male patients with gastritis are found to have a high risk of developing peptic ulcer diseases. However, how gastritis or gender difference affects gastric ulcer formation is unclear. The present study aimed to investigate the relationship between ethanol-induced acute gastritis and gastric ulcer formation in rats. Methods: Acute gastritis or gastric ulcer was induced in the rat stomach by 80% ethanol or 60% acetic acid, respectively. Rats were killed either with gastritis alone or thereafter at day 1, 3 or 6 after ulcer induction. The number of proliferating and apoptotic cells, the mucosal mucus and prostaglandin E-2 (PGE(2)) level were also determined. Results: Male rats with acute gastritis potentiated gastric ulcer formation, while gastritis in female rats prevented ulceration. Female rats with gastritis had a significantly faster ulcer-healing rate. More apoptotic cells were found in the gastritis groups, but only the female gastritis group produced more proliferating cells and had a decrease in the apoptosis-over-proliferation ratio. The mucus level was higher in female rats after ulcer induction. Mucosal PGE(2) level was higher in female rats with acute gastritis. Both mucus and PGE(2) were increased during ulcer healing in both genders. Conclusions: This study shows that gender difference plays a role in the pathogenesis of ulcer formation. The number of cells with apoptosis or proliferation determines, in part, the gender difference on gastric ulcer formation in rats. Gastric PGE(2) not only contributes to this process, but also together with gastric mucus participates in the ulcer-healing process in the stomach. (C) 2001 Blackwell Science Asia Pty Ltd.