Effect of pirenzepine and PGE2 on taurocholic acid-induced gastric lesions.

Cytoprotective activity of Pirenzepine (PZ) and Prostaglandin E2 (PGE2) was investigated in the gastric damage induced by taurocholic acid (TA) in the rat. Gastric mucosal potential difference (PD) and gross mucosal erosions were measured. Intravenous PZ (18 mg/kg) and PGE2 (5 micrograms/kg) prevented both the sharp decrease of PD and the gastric lesions caused by intragastric TA (40 mM). When TA administration preceeded drug treatment, both compounds reversed the PD fall but only PZ was able to restore gross mucosal integrity. It is thought that TA causes gastric damage by producing back-diffusion of H+ ions across the mucosal layer. It is speculated that antimuscarinic, such as PZ, might reduce gastric damage either by preventing, at the submucosal level, the spreading of cytolesive process triggered by H+ retro-diffusion and/or by inhibition of acid secretion in the depth of the gastric glands.