PLASMA-CONCENTRATIONS OF ISLET AMYLOID POLYPEPTIDE AFTER GLUCAGON ADMINISTRATION IN TYPE-2 DIABETIC-PATIENTS AND NONDIABETIC SUBJECTS

Islet amyloid polypeptide (IAPP) is the main constituent of pancreatic islet amyloid, observed in the pancreases from patients with Type 2 d iabetes mellitus. IAPP is synthesized by the pancreatic beta-cells. In order to study the secretion characteristics of IAPP in Type 2 diabet es mellitus, plasma IAPP was measured during a provocation test with g lucagon in 33 Type 2 diabetic patients and 18 non-diabetic subjects. T he median fasting IAPP level was 5.7 (range 1.1-13.1) pmol l-1 in the 27 patients treated with oral hypoglycaemic agents and 2.7 (1.9-5.9) i n the 6 patients on insulin. In the non-diabetic group fasting IAPP wa s S.7 (2.2-10.1). Six minutes after glucagon administration median IAP P rose to 9.4 (1.7-31.0) and 6.1 (5.1-10.2) in the respective diabetic groups, and to 16.8 (4.0-41.0) in the non-diabetic subjects (p much l ess than 0.05). The correlation coefficient between change in IAPP and change in C-peptide was 0.68 in the diabetic group. We conclude that intravenous administration of glucagon stimulates IAPP release from th e beta-cell. This provocation test is easy to perform and can be used on a large scale in the study of IAPP secretion in Type 2 diabetes mel litus.