Morphological and histochemical variations of mucous and oxynticopeptic cells in the stomach of the seps, Chalcides chalcides

Mucous and oxynticopeptic cells in the gastric mucosa of the seps, Chalcide s chalcides (Linnaeus, 1758) were examined by standard histochemical staini ng methods and by lectin histochemistry. The epithelial mucous cells lining the surface of the stomach and the mucous cells of the fundic glands elabo rated mainly neutral glycoproteins with beta(1,4)GlcNAc oligomers, GalNAc g lycosidic residues and Gal beta 1,3GalNAc terminal sequences. The mucous ce lls of the fundic glands were stained specifically with the Paradoxical Con A method. The mucosecreting cells of the pyloric glands produced neutral g lycoproteins, with beta(1,4)GlcNAc oligomers, GalNAc residues and Gal beta 1,3GalNAc terminal sequences. Terminal L-fucose bound to the penultimate Gl cNAc residues, and/or difucosylated oligosaccharides were also present. The pyloric glands did not stain with the Paradoxical Con A procedure. The mor phology of the oxynticopeptic cells changes from the oral to the aboral reg ion of the fundic mucosa. In the oral fundic tract the oxynticopeptic cells showed cytoplasm filled with zymogen granules, while in the aboral fundic region these cells contained few zymogen granules and showed cytoplasm full of empty vesicles, typical of the acid secreting cells. A secretion gradie nt of proteolytic enzymes and hydrochloric acid along the fundic mucosa of the seps can be hypothesised.