title: Pancreatic polypeptide in islet cell tumors. Morphologic and functional correlations.
abstract: Twelve islet cell tumors and one islet cell hyperplasia were studied with immunocytochemical and radioimmunoassay methods. With immunocytochemical staining, all six insulinomas, one mixed insulinoma-glucagonoma, and four gastrinomas were positive for insulin, insulin and glucagon, and gastrin, respectively. Pancreatic polypeptide (PP) was positive in three insulinomas and one mixed insulinoma-glucagonoma. All of the tumors were positive for neuron-specific enolase (NSE). Radioimmunoassays of tissue extracts further disclosed that all functioning tumors contained more than one pancreatic hormone. PP concentrations of two insulinomas and one mixed insulinoma-glucagonoma were higher than that of normal control pancreases. A study of protein meal-stimulated PP secretion revealed that three of the insulinoma cases and two gastrinoma cases exhibited higher plasma PP levels than the age-matched controls. The findings suggest that: both functioning and nonfunctioning islet cell tumors derive from neuroendocrine cells positive for NSE; all functioning islet cell tumors appear to contain PP in the tumor tissue as a minor component; as many as 70% of the patients with islet cell tumors present with abnormally higher plasma PP levels after protein meals; and a study of meal-stimulated PP secretion may well be used as a marker for the presence of functional islet cell tumors.
authors.forename: T
authors.initials: T
authors.lastname: Tomita
authors.forename: J R
authors.initials: JR
authors.lastname: Kimmel
authors.forename: S R
authors.initials: SR
authors.lastname: Friesen
authors.forename: V
authors.initials: V
authors.lastname: Doull
authors.forename: H G
authors.initials: HG
authors.lastname: Pollock
mesh_terms: D007516:Adenoma, Islet Cell / Q000032:analysis* / Q000378:metabolism / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005934:Glucagon / Q000032:analysis; D006801:Humans; D007328:Insulin / Q000032:analysis; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000032:analysis* / Q000378:metabolism / Q000473:pathology; D010191:Pancreatic Polypeptide / Q000032:analysis* / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000032:analysis
chemical_list: D007328:Insulin; D010191:Pancreatic Polypeptide; D005934:Glucagon; D010751:Phosphopyruvate Hydratase