The endocrine pancreas of Podarcis s. sicula Raf.: an immunocytochemical study at light and electron microscopic levels.

The endocrine pancreas of Podarcis s. sicula Raf. was investigated at light and electron microscopic levels using immunocytochemical methods. It was constituted by endocrine islets, which were concentrated more in the splenic than in the duodenal region, and never formed large clusters. At the light and electron microscope, with the peroxidase-antiperoxidase reaction (PAP) and the colloidal gold technique, four cell types were identified: glucagon-positive A-cells, insulin-positive B-cells, somatostatin-positive D-cells and pancreatic polypeptide-positive F- or PP-cells. F- or PP-cells showed a different regional distribution, being absent or very rare in the splenic lobe of the pancreas and numerous in the duodenal lobe, where they were seldom found in the islets, but were scattered in the exocrine parenchyma. The functional meaning of F-cells is discussed. The E.M. observations were carried out at the CIRUB (Centro Interdipartimentale di Ricerca sulle Ultrastrutture Biologiche) of the University of Naples.