PARADOXICAL DSP-4 EFFECTS - PROTECTION AGAINST GASTRIC-EROSIONS AND DEPLETION OF MUCOSAL GLYCOPROTEINS

We have previously reported that rats pretreated with the central noradrenergic neurotoxin DSP-4 are protected against 23 h restraint-induced gastric erosions. To elucidate the peripheral mechanisms of this protection, we undertook direct biochemical analyses of the gastric mucosa in terms of glycoproteins and proteins. A simple method for preparation of gastric mucosa devoide of the muscular stomach wall tissue is described. A restrain-induced decrease in gastric wet weight and mucosal glycoprotein content was revealed. Restraint had no effect no mucosal protein content, and no changes were found in gastric wall glycoprotein or protein content. Despite showing protection against restrain-induced gastric erosions, unrestrained DSP-4-treated animals exhibited reduced mucosal wet weight mucosal glycoprotein content when compared to unrestrained controls. After the stress period, no significant differences on mucosal weight or glycoproteins could be detected between control and DSP-4 treated animals. The results indicate that the protective effect of DSP-4 in this paradign is not due to enhanced gastric mucosal protection against erosive factors. We suggest that an additional effect of central nervous NA depletion by DSP-4 may be elimination of aggresive factors which precipitate overt ulcers. © 1990.