Partial Prevention of Ethanol Damage of Human Gastroduodenal Mucosa by Prostaglandin E₂ in Vitro

Abstract

Biopsies were taken endoscopically from the fundic, antral, and upper duodenal region of healthy volunteers and gastric ulcer patients and were incubated in carbogen-saturated and buffered Medium 199 at 37°C. The rate of DNA synthesis, estimated as incorporation of tritiated thymidine into tissue DNA, was determined as an index of cellular integrity. During the 30-min incubation, ethanol (25% v/v) significantly (p < 0.01) depressed DNA synthesis by about 50% in the gastroduodenal mucosa of normal subjects and even by two thirds in the gastric mucosa of gastric ulcer patients. Prostaglandin E₂ (PGE₂) by itself (1 mg/50 ml) had no stimulatory effect on DNA synthesis; it did, however, reduce the drastic fall in DNA synthesis due to ethanol (p < 0.005) when administered concomitantly. The basic process underlying cytoprotection by PGE₂ in vitro remains to be elucidated. Some indirect mechanisms, such as stimulation of gastric mucosal blood flow, are ruled out by these experiments.

Key-words:

• Cytoprotection
• DNA synthesis
• duodenum
• ethanol
• gastric mucosa
• gastric ulcer
• prostaglandin E₂
• RNA content
• stomach