Abstract
To clarify the interrelationship between endocrine and exocrine pancreatic functions, external pancreatic secretions and plasma pancreatic enzyme responses to pancreozymin-secretin were analyzed in 57 primary diabetic subjects. The effects of insulin on exocrine pancreatic functions were also studied in streptozotocin-diabetic rats.
1. Volume, maximum bicarbonate concentration and enzyme output (amylase, trypsin and lipase) of duodenal contents obtained after pancreozymin-secretin (P-S) stimulation decreased significantly in diabetic subjects when compared to normal subjects. Among these indices, the most marked abnormalities were observed in enzyme output, especially in amylase output. Low amylase output was found more, frequently in poorly controlled diabetic subjects.
2. Positive plasma enzyme responses to P-S were observed more frequently in poorly controlled subjects, judged as positive when one or more of the three enzymes were provoked. Positive plasma enzyme responses found in poorly controlled diabetic states were markedly improved after insulin treatment. Abnormally high plasma amylase and lipase levels observed in diabetic ketoacidotic coma were also reduced to normal levels after the metabolic derangement was improved by insulin.
3. In streptozotocin-diabetic rats, both acute and chronic, only amylase output in duodenal contents to P-S stimulation decreased significantly when compared to normal rats, as a result of the very low amylase content in the pancreatic tissues. The plasma amylase level was low an
was not changed significantly by P-S stimulation. Plasma lipase, on the other hand, was easily provoked in diabetic rats. Such abnormalities as low amylase content, low amylase output, low plasma amylase level, and positive plasma lipase response were restored to normal after insulin treatment.
These findings indicate that insulin plays an important role in maintaining normal exocrine pancreatic function. These exocrine pancreatic dysfunctions secondary to diabetes mellitus are discussedas “diabetic exocrine-pancreatopathy”.
