ENDOCRINE-CELLS IN THE RAT PANCREATIC AND BILE-DUCT SYSTEM - ALTERATION IN DIABETES

Endocrine cells of the pancreatic and bile duct system of the diabetic rat were characterized with reference to their influence on duct func tion. In streptozotocin-induced diabetic rats, the endocrine cells sho wed various changes in number and topographic distribution along the e pithelial lining of the duct system. With the exception of insulin cel ls, which demonstrated a marked decrease, the number of duct endocrine cells generally increased in the duct system of the diabetic animal, particularly in the terminal portion of both the common hepatic and th e accessory pancreatic ducts encompassed by the muscle sphincters. Amo ng them, the cells secreting somatostatin, a potential peptide inducin g contraction of the muscle sphincter, showed a remarkable increase in the opening portion of the common hepatic and the accessory pancreati c ducts of the diabetic animal. The duct cells producing glucagon and pancreatic polypeptide, the hormones exerting an inhibitory effect on exocrine secretion of duct and acinar cells, also increased significan tly in the duct system of the diabetic animal. These results suggest t hat the duct endocrine cells are closely related, not only to function al properties of the duct system, but also to disorders of the pancrea s and biliary tract in diabetes.