Tagliafierro_1976_Riv.Istochim.Norm.Patol_20_217

Using histological and histochemical methods for the identification of biogenic amins, phenolic and indolic groups, and of substances with a proteine and carbohydrate nature, it has been possible to identify at least five types of endocrine cells in the gastric mucose of Scyliorhinus stellaris and Scyliorhinus canicula. One of these, a type I cell, localised mainly in the piloric portion, shows morphological and histochemical characteristics which are perfectly comparable with those of the enterochromaffin type found in the gastro-intestinal tract of mammals. On the other hand, the four remaining cellular types are more difficult to define; three of these latter are present solely in the pyloric mucose, i.e., (a) type II cells with slightly fluorescent and metachromatic granules, with a positive reaction to the Grimelius test and to proteine test, and completely negative and argentaffin methods, (b) type III cells with non-fluorescent granules, but metachromatic and postive to argentaffin methods, and (c) type IV cells with slightly (argyrophilic) granules, strongly metachromatic and positive to the PAS test and to the tryptophan test, respectively. Types II and IV have been hypothetically correlated with the G and D cells, respectively, of mammals. The fifth cellular type, present solely in the central portion of the stomach has exclusively argyrophilic granules. This latter cellular type is considered similar to the ECL type, mammalian cell. No hypothesis, however, has yet been ventured with respect to the cells belonging to the third group.