MUCOSUBSTANCES OF THE RAT GASTRIC MUCOSA STUDIED BY MEANS OF SEVERAL HISTOCHEMICAL METHODS

Abstract

Distribution of mucosubstances in the rat gastric mucosa was studied by radioautography using 35S-sodium sulfate, several light microscopic histochemical procedures, the periodic acid thiocarbohydrazide silver proteinate (PA-TCH-SP) method and postembedding staining with Iectin (wheat germ agglutinin) ferritin conjugates. Histochemical staining revealed that the superficial covering epithelium contained a large amount of neutral mucosubstances, whereas the foveolar and isthmus mucous cells produced both sialomucins and sulfomucins. Active incorporation of 35S was observed in the fundic foveolus and isthmus as well as the pyloric gland. The mucous neck cells contained sialomucin. The PA-TCH-SP method stained the covering epithelium, the epithelium of the foveolar and isthmus mucous cells and the mucous neck cells. All cell organellae which took part in the formation of granule substances in the gastric mucosa were stained by this method. The cytoplasm of the mucous neck cells was extensively occupied with round PA-TCH-SP positive granules. As the epithelium of the pits matured, the granules increased in size. The apical portion of the covering epithelium was exclusively occupied with large round to oval granules. Many of them showed a bipartite structure after PA-TCH-SP staining, reaction products were observed only in the peripheral region of these granules. Conversely, the development of other cell organellae became less prominent as these epithelia matured. Postembedding staining with lectin (wheat germ agglutinin)-ferritin conjugates stained secretory granules of all these mucous cells with different staining patterns. In the covering epithelium, the conjugate stained only the peripheral region of the granules.