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
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Insulin-dependent Diabetes
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Insulin-induced Hypoglycemia
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Insulitis
