[Pancreatic polypeptide islets and glucagon islets : distinct topographic distribution in rat pancreas].

The immunocytochemical technique for the cellular localization of hormones allows a precise identification of islet cell types responsible for the production of insulin, glucagon, somatostatin and pancreatic polypeptide. A systematic study of Rat pancreas has revealed a hitherto undescribed morphological heterogeneity of islets. In fact, the cellular composition of islets differs according to their anatomical distribution. The "PP islets" are preferentially located in the inferior 2/3 of the head of the pancreas, whilst "glucagon islets" populate the remainder of the gland.