Diabetes, Vol 39, Issue 5 639-642, Copyright © 1990 by American Diabetes Association
Islet amyloid polypeptide response to glucose, insulin, and somatostatin analogue administration
T Mitsukawa, J Takemura, J Asai, M Nakazato, K Kangawa, H Matsuo and S Matsukura
Third Department of Internal Medicine, Miyazaki Medical College, Japan.
We determined islet amyloid polypeptide (IAPP) response in plasma to oral
and intravenous glucose administration and intravenous insulin injection in
nondiabetic subjects. Moreover, we studied the effect of somatostatin
analogue SMS 201-995 on glucose-induced IAPP secretion in nondiabetic
subjects. Plasma IAPP concentration was determined by radioimmunoassay.
Oral administration of 75 g glucose (n = 8) significantly increased plasma
IAPP levels from 4.5 +/- 0.7 to 14.0 +/- 1.7 pM (P less than 0.01) 60 min
after administration. Intravenous administration of 10 g glucose (n = 7)
also caused a significant increase in plasma IAPP from 5.0 +/- 0.4 to 11.6
+/- 0.9 pM (P less than 0.01) 5 min after injection. Plasma IAPP
significantly decreased from 5.1 +/- 0.4 to 2.9 +/- 0.4 pM (P less than
0.01) 60 min after intravenous insulin injection (n = 8). Pretreatment with
SMS 201-995 completely abolished IAPP and insulin secretion to intravenous
glucose injection. A significant correlation was found between plasma IAPP
and insulin levels in oral and intravenous glucose administration and
between plasma IAPP and C-peptide levels during insulin-induced
hypoglycemia. These results suggest that IAPP is cosecreted with insulin in
response to a glucose load and secretion of IAPP is inhibited by
hypoglycemia and somatostatin. IAPP may serve as a novel pancreatic hormone
to control carbohydrate metabolism.