Diminished Immunoreactive Gastric Inhibitory Polypeptide Response to a Meal in Newly Diagnosed Type I (Insulin-Dependent) Diabetics*

Abstract

The release of immunoreactive gastric inhibitory polypeptide (IR-GIP) in response to a standard meal was examined in 10 normal subjects and 15 type I (insulin-dependent) diabetics 7 days (test I), 14 days (test II), and 3 months (test III) after time of diagnosis. During all three tests, the diabetics had significantly lower plasma IR-GIP concentrations than the controls from 15-90 min after the standard meal. The IR-GIP response in the diabetics measured as the integrated area under the response curve corresponded to 70% of that of normal subjects. beta-cell function evaluated from the C-peptide response to the meal increased significantly from test I to test III whereas the IR-GIP response was similar during all three tests. As GIP is known to potentiate glucose-induced insulin secretion and possibly the biosynthesis of insulin, the low IR-GIP responses in subjects with type I diabetes may significantly influence insulin levels and hyperglycemia.

Lower glucose-dependent insulinotropic polypeptide (GIP) response but similar glucagon-like peptide 1 (GLP-1), glycaemic, and insulinaemic response to ancient wheat compared to modern wheat depends on processing

“…GIP and GLP-1 concentrations in plasma were measured using specific radioimmunoassays after extraction of plasma with 70% ethanol (vol/vol, final concentration). For the GIP assay we used the C-terminally directed antiserum R 65, which crossreacts fully with human GIP, but not with GIP 8000, whose chemical nature and relation to GIP secretion is uncertain (Krarup et al, 1983). Human GIP and 125-I human GIP (70 MBq/nmol) were used for standards and tracer.…”

Steroid-induced insulin resistance and impaired glucose tolerance are both associated with a progressive decline of incretin effect in first-degree relatives of patients with type 2 diabetes

“…Plasma samples were assayed for total GLP-1 as previously described [24], using a radioimmunoassay with antiserum specific for the C-terminal of the GLP-1 molecule (antiserum 89390, produced in house), which therefore reacts equally with intact GLP-1 and the primary (N-terminally truncated) metabolite. Total GIP was measured using the C-terminally directed antiserum R65, produced in house [25,26], which reacts fully with intact GIP and the N-terminally truncated metabolite. The glucagon assay is directed against the C-terminal (antibody 4305, produced in house) and measures glucagon of mainly pancreatic origin [27][28][29].…”

Circadian rhythms of GIP and GLP1 in glucose-tolerant and in type 2 diabetic patients after biliopancreatic diversion

“…GIP and GLP1 concentrations in plasma were measured after extraction of plasma with 70% ethanol (vol./vol., final concentration) according to techniques developed at the Panum Institute, University of Copenhagen [20,21].…”