A Newly Recognized Pancreatic Polypeptide; Plasma Levels in Health and Disease

Abstract

Immunohistochemical studies show that aPP is stored in an endocrine-type cell disseminated in the exocrine parenchyma of the chicken pancreas (aPP cells are seldom found in islets of chicken pancreas) and different from islet cell types A, B, and D. Moreover, hPP and several other mammalian pancreatic polypeptides have also been localized to an endocrine-type cell different from islet A, B, and D cells. The PP cells are found both in the peripheral part of the islets and scattered throughout the exocrine parenchyma. In man, hPP cells are found in the periphery of islets and also scattered in the exocrine pancreatic parenchyma and in the epithelium of small and medium-sized ducts. In 1976, Gersell and his associates confirmed that hPP cells are located both within and outside of the islets. This chapter explains distribution of pancreatic polypeptide in tissues, radioimmunoassay of hPP, regulation of secretion of hPP in healthy subjects, and hPP in disease states.