Alternation of gastric mucosal glycoprotein (lectin-binding pattern) in gastric mucosa in stress. A light and electron microscopic study. Gastric mucosal cells of the rat glandular stomach were studied by light and electron microscopic procedures by use of lectins in the development of acute gastric mucosal lesions. Effects of the H2-receptor antagonist sofalcone (2'carboxymethoxy-4,4'-bis 3-methyl-2) and truncal vagotomy with pyloroplasty on lectin binding sites and distribution were also investigated. Biotinylated lectins in combination with ABC (avidin-biotinyl peroxidase complex) method were used for light and horseradish peroxidase (HRP)-labeled lectins for electron microscopic studies. Gastric mucosal cells showed the specific binding pattern for each lectin by light microscopy. Especially, binding sites and distribution of peanut agglutinin (PNA) were characteristic after induction of stress, truncal vagotomy, and administration of each drug. Staining and distribution increased in the gastric mucosa upward and downward after that. In electron microscopic studies, PNA strongly stained the membranes of the intracellular secretory canaliculi of a parietal cell. These results suggested that alternation of binding sites and distribution was regulated by change of gastric mucosal blood flow and of acidity in the parietal cells. Therefore, increase of glycoconjugate distribution is supposed to be a possibility of cytoprotective effect for a change of environment in the parietal cells. 