Relationship between the severity of diabetes mellitus and pancreatic exocrine dysfunction in rats.

The relationship between the severity of diabetes mellitus and pancreatic exocrine function was investigated in rats made diabetic by injecting 3 different doses of streptozotocin (30, 45 or 60 mg/kg body weight). The expected correlation was obtained between the dose of streptozotocin and degree of elevation of blood glucose and decrease in pancreatic insulin content. Pancreatic amylase content of the diabetic rats was less than that of control rats and was in parallel with less values in pancreatic insulin content. On the other hand, trypsinogen content of diabetic rats was greater than that of control. Basal and caerulein-stimulated flow rates of pancreatic juice and protein output were similar in the control and in all 3 groups of diabetic rats. In contrast, there was a graded response of amylase and trypsinogen, depending upon the content of each enzyme in the pancreas. Both basal and caerulein-stimulated amylase outputs from diabetic rat pancreas were significantly reduced in parallel with the severity of diabetic state, but were similar to those from the control rats when related to the total pancreatic content. The present findings indicate that pancreatic exocrine dysfunction in diabetes mellitus is closely related to the severity of the disease, but the secretory dynamics in the perfused pancreas are not altered.