Gastric mucosal protection during restraint stress in rats: alteration in gastric adherent mucus and dissolved mucus in gastric secretion.

In order to assess the role of gastric mucus glycoproteins in the protection of gastric mucosa against stress ulceration, albino rats were subjected to restraint stress for 20 h, at the end of which the visible mucus adhering to the gastric mucosa, and the components of non-dialysable mucosubstances --sialic acid, hexoses, fucose and hexosamines were estimated in the gastric secretion. The molar ratio between the carbohydrate components of the dissolved mucus were also calculated. Restraint stress was found to reduce the gastric adherent mucus in oxyntic and pyloric gland areas, to decrease the concentration of sialic acid and hexosamines in gastric secretion and to increase the ratios of hexoses to hexosamines, and fucose to sialic acid. It was concluded that the gastric adherent mucus plays an important role in protecting the gastric mucosa against ulceration, and that this protective force breaks down during restraint stress, as indicated by reduced gastric adherent mucus and a low level of carbohydrate components in the gastric secretion.