Esculine, ranitidine and carbenoxolone: different modes of action on gastric mucosa.

1. This study was designed to determine the antiulcerogenicity of esculine in various types of experimentally induced gastric ulcers in which the appearance of lesions is due to an ischemic process: cold-restraint stress and pylorus-ligated induced ulcers. 2. In the first experimental model, esculine (50 mg/kg) produced a significant diminution not only in the number of haemorrhagic stomachs (21.5% by 37.5% of the controls) but also in the ulcer index, U.I. (1.00 +/- 0.63, P less than 0.05). 3. When the mucosal damage was induced as a consequence of the pylorus-ligated gastric secretion, pretreatment of esculine (25 and 50 mg/kg) prevented the formation of gastric lesions (12.4 +/- 2.8, P less than 0.05 and 12.2 +/- 1.20, P less than 0.005), although it was less effective than ranitidine (2.8 +/- 1.8, P less than 0.025). However a significant reduction on the acidity with a dose of 25 mg/kg was observed (31.69 +/- 6.42, P less than 0.025). For the rest of the studied parameters: pepsin, histamine and Na and K electrolytes no differences with regard to the control groups were produced. 4. The effects of esculine on mucosal lesions produced by intragastric instillation of 1 ml of absolute ethanol, were also studied. In this model esculine did not show any protective effect and high U.I. values were obtained.