Morphological changes in the human endocrine pancreas induced by chronic excess of endogenous glucagon.
The non-tumoral endocrine pancreas from a patient with elevated plasma levels of glucagon due to a malignant glucagonoma was studied immunocytochemically, ultrastructurally and morphometrically. Compared with normal pancreatic islets from control subjects, those of the pancreas from the patient with a glucagonoma showed an almost complete disappearance of A cells, a decrease in immunoreactive insulin in B cells associated with cytological features indicating enhanced synthesis and secretion of this hormone, and an increase in immunoreactive somatostatin and pancreatic polypeptide (PP) accompanied by unusually high numbers of D and PP cells. In addition, numerous B cells were found outside the islets, either forming micro-islets or scattered in the exocrine tissue (nesidioblastosis). The possible mechanisms involved in determining the changes in the secretory activity of B cells and the alterations in the cell composition of the islets are discussed.
Department of Human Anatomy, University of Florence, Italy.
D
D
Bani
G
G
Biliotti
T B
TB
Sacchi
D000293:Adolescent; D000328:Adult; D005260:Female; D005934:Glucagon / Q000032:analysis*; D005935:Glucagonoma / Q000473:pathology*; D006801:Humans; D007124:Immunoenzyme Techniques; D007328:Insulin / Q000032:analysis; D007515:Islets of Langerhans / Q000737:chemistry / Q000473:pathology* / Q000648:ultrastructure; D008875:Middle Aged; D010179:Pancreas / Q000473:pathology / Q000648:ultrastructure; D010190:Pancreatic Neoplasms / Q000473:pathology*; D010191:Pancreatic Polypeptide / Q000032:analysis; D013004:Somatostatin / Q000032:analysis
D007328:Insulin; D013004:Somatostatin; D010191:Pancreatic Polypeptide; D005934:Glucagon