CYTOPROTECTIVE ACTIVITY IN THE GASTRIC-MUCOSA OF RATS EXPOSED TO CARBON TETRACHLORIDE-INDUCED LIVER-INJURY

The present study was undertaken to evaluate the cytoprotective activi ty in the gastric mucosa of rats subjected to CCl4-induced liver injur y. Response of gastric mucosa to absolute ethanol insult or acid (pylo rus ligation) after CCl4 challenge was analyzed. Intraperitoneal admin istration of CCl4 increased plasma AST and ALT, but liver protein and glycogen levels were decreased; in addition, gastric acid secretion wa s significantly increased with respect to control animals (1541 +/- 26 6 vs. 629 +/- 25 mu eq H+; p < 0.001). Microscopical gastric erosions were observed in 3/10 animals after CCl4 challenge. Pylorus-Ligated as well as CCl4-challenged rats developed increased susceptibility to ga stric lesions, compared to control (lesion indices: 4.6 +/- 0.20 vs 2. 8 +/- 0.13; p < 0.05), while showing increased resistance to absolute ethanol-induced gastric damage (30.4 +/- 11.2 vs 89.7 +/- 9.7 mm, p < 0.01). PGE(2) levels in the gastric mucosa were not influenced by expo sure to CCl4. Ultrastructural studies revealed the presence of continu ous ethanol-resistant and apparently more adherent layer of mucus in C Cl4-challenged animals. Morphological evaluation revealed an increase in Alcian blue-stained mucus. A dual condition of enhanced sensitivity to HCl with increased tolerance to ethanol was observed in gastric mu cosa of CCl4-treated animals. These observations could be explained by the amount and/or composition of protective mucus layer in the gastri c mucosa.