[Changes in gastrointestinal mucins caused by attapulgite. Experimental study in rats]

A histochemical study was carried out to evaluate the changes occurring in mucins secreted by the rat stomach and intestine following a 7 day-treatment with a cytoprotective clay: attapulgite. Staining of gastrointestinal sections was performed with periodic acid-Schiff reagent, alcian blue pH 2.5 and pH 1.0, and with lectin conjugated with horseradish peroxidase for detecting complex carbohydrates. When compared with controls, attapulgite induced an increase in carboxylic mucin content in the cells of the crypts associated with a decrease in sulphated mucins and in binding with soy bean agglutinin in surface epithelial cells in the fundic zone. In the antrum, staining with wheat germ agglutinin was decreased in the crypt cells while Ulex europaeus agglutinin affinity was increased in the glandular cells. The duodenum was characterized by increased binding with Ulex europaeus agglutinin in Brunner's glands. These results show that the polysaccharidic components of the gastrointestinal glycoproteins are modified by attapulgite, and this mechanism may be involved in its cytoprotective effects.