CYTO-PROTECTION BY PROSTAGLANDINS IN RATS - PREVENTION OF GASTRIC NECROSIS PRODUCED BY ALCOHOL, HCL, NAOH, HYPERTONIC NACL, AND THERMAL-INJURY

Abstract

Oral administration to fasted rats of absolute ethanol, 0.6 N HCl, 0.2 N NaOH 25% NaCl or boiling water produced extensive necrosis of the gastric mucosa. Pretreatment with several prostaglandins [PG] of the A, E or F type, orally or s.c., prevented such necrosis and the effect was dose-dependent. This property of prostaglandins is called cytoprotection. The protective effect against oral administration of absolute ethanol was maximal 1 min after PGE2 given orally, and 15-30 min after PGE2 given s.c. Cytoprotection by prostaglandins is unrelated to the inhibition of gastric acid secretion since it is maximal at doses that have no effect on gastric secretion and antisecretory compounds (cimetidine, methscopolamine bromide) and antacids are not cytoprotective. Although the mechanism of gastric cytoprotection is unknown, prostaglandins appear to increase the resistance of gastric mucosal cells to the necrotizing effect of strong irritants. Apparently certain prostaglandins, by a mechanism other than inhibition of gastric acid secretion, maintain the cellular integrity of the gastric mucosa and might be beneficial in the treatment of diseases in which gastric mucosal injury is present.