Impaired Response of Human Pancreatic Polypeptide to Insulin-Induced Hypoglycemia in Insulin-Dependent Diabetics

Summary

The secretory response of human pancreatic polypeptide (HPP) producing cells (PP-cells) to hypoglycemia was studied in order to clarify whether the function of PP-cells is impaired along with the dysfunction of A- and B-cells in the pancreatic islets in insulin-dependent diabetics.

Hyperglycemia followed by hypoglycemia was induced by successive intravenous administration of glucose (0.5 g/kg) and insulin (0.2-0.4 U/kg) at an interval of 30 min in 8 controls, 12 insulin-independent diabetics and 10 insulin-dependent diabetics. During hyperglycemia no difference in the plasma HPP decline was observed between the three groups. However, “HPP-area”, the index of the response of HPP to hypoglycemia, was significantly smaller in insulin-dependent diabetics, 7860 ± 3040 pg · min/ml (mean ± SEM), than either in controls, 28490 ± 4630 pg · min/ml (p < 0.005), or in insulin-independent diabetics, 21630 ± 4720 pg · min/ml (p < 0.025).

These results indicate that a marked impairment of HPP response to hypoglycemia exists in insulin-dependent diabetes. The hypofunction of HPP producing cells together with A- and B-cells may imply that extensive destruction of pancreatic islets plays some role in the development of insulin-dependent diabetes.

Key-Words:

Pancreatic Polypeptide - Insulin-dependent Diabetes - Insulin-induced Hypoglycemia - Insulitis