Exocrine and endocrine secretion from isolated perfused rat pancreas with islet cell tumors induced by streptozotocin and nicotinamide

Pancreatic exocrine and endocrine function in the rat with islet cell tumors induced by streptozotocin and nicotinamide was studied in the in vitro isolated perfused pancreas. The tumor-bearing pancreas secreted significant amounts of insulin even at 2.8 mM glucose stimulation. Further, insulin response to 8.3 mM glucose stimulation was greater in the tumor-bearing pancreas than in the control. Not only endocrine, but also exocrine, disorders were found in the rat pancreas bearing islet cell tumors. In contrast to the increased response of insulin, amylase output in response to 0.1 ng/ml cerulein was significantly lower in the tumor-bearing than in the control pancreas, although there was no difference in pancreatic juice flows from both groups. These results suggest that enzyme secretory function of the pancreas with islet cell tumors may be suppressed in the presence of some interrelationship between the exocrine and endocrine portion of the pancreas with islet cell tumors.