Pancreatic insulin secretion in exocrine pancreatic cancer

Adenocarcinoma of the exocrine pancreas in man is associated with a high incidence of diabetes mellitus. Hyperglycemia in humans with pancreatic cancer is presumed to be caused by destruction of islets of Langerhans with a resultant impairment in pancreatic insulin secretion. This hypothesis was tested in an animal model of exocrine pancreatic cancer. Carcinoma of the pancreas was induced in male Syrian golden hamsters by weekly injection of N-nitrosobis(2-oxopropyl)amine. Using an ex vivo isolated perfused pancreas preparation, the capacity of cancer-bearing pancreata to secrete insulin in response to glucose and arginine was compared to normal animals of the same age. Animals with pancreatic cancer demonstrated a normal insulin secretory response to both glucose and arginine. Thus the hypothesis that exocrine pancreatic cancer causes diabetes by directly impairing insulin release must be questioned and alternative explanations for the association of diabetes and pancreatic cancer should be sought.