[Histochemistry and ultrastructure of gastric glandular cells of the Raja asterias delaroche (Elasmobranchi)].

The presence of different kinds of cells in the gastric tubular glands of the Elasmobranchian Cartilaginous fish "Raja asterias" was investigated by histochemical and ultrastructural methods. Our study demonstrates that the gastric glands, unlike those of the other non-Mammalian Vertebrates, contain in the distal portion, near the neck zone, the oxyntic-like cells, and in the proximal portion the zymogenic-like cells. The former presents histochemical and ultrastructural patterns similar to the Mammalian oxyntic cells, the latter to the Mammalian peptic cells. Between these two types there are always cells with intermediate aspects. These features support the presence of two different stages in the secretory activity: at first the gastric tubular cell is implicated in the secretion of hydrochloric acid, later on, in the secretion of pepsinogen.