C Orskov1, A Wettergren, J J Holst. 1. Dept. of Medical Anatomy, Panum Institute, University of Copenhagen, Denmark.
Abstract
BACKGROUND: The insulinotropic hormones gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), secreted from the K-cells of the upper small intestine and from the L-cells of the lower small intestine, respectively, are thought to be responsible for intestinal stimulation of insulin secretion. If true, their plasma concentrations should parallel the meal-related diurnal changes in plasma insulin concentrations. METHODS: Using COOH-terminal assays, thought to reflect accurately their rates of secretion, we measured circulating levels of GIP and GLP-1 in six normal subjects for 15 h of a day, during which they ate three mixed meals. RESULTS: Both GIP and GLP-1 concentrations increased significantly and in parallel with insulin in response to all three meals. The plasma insulin concentrations correlated significantly with both GIP and GLP-1 values throughout the study period (correlation coefficients, 0.49 +/- 0.07 and 0.56 +/- 0.05; p < 0.001). CONCLUSIONS: These results support the notion that GLP-1 and GIP are important incretin hormones.
BACKGROUND: The insulinotropic hormones gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), secreted from the K-cells of the upper small intestine and from the L-cells of the lower small intestine, respectively, are thought to be responsible for intestinal stimulation of insulin secretion. If true, their plasma concentrations should parallel the meal-related diurnal changes in plasma insulin concentrations. METHODS: Using COOH-terminal assays, thought to reflect accurately their rates of secretion, we measured circulating levels of GIP and GLP-1 in six normal subjects for 15 h of a day, during which they ate three mixed meals. RESULTS: Both GIP and GLP-1 concentrations increased significantly and in parallel with insulin in response to all three meals. The plasma insulin concentrations correlated significantly with both GIP and GLP-1 values throughout the study period (correlation coefficients, 0.49 +/- 0.07 and 0.56 +/- 0.05; p < 0.001). CONCLUSIONS: These results support the notion that GLP-1 and GIP are important incretin hormones.
Authors: T D Müller; B Finan; S R Bloom; D D'Alessio; D J Drucker; P R Flatt; A Fritsche; F Gribble; H J Grill; J F Habener; J J Holst; W Langhans; J J Meier; M A Nauck; D Perez-Tilve; A Pocai; F Reimann; D A Sandoval; T W Schwartz; R J Seeley; K Stemmer; M Tang-Christensen; S C Woods; R D DiMarchi; M H Tschöp Journal: Mol Metab Date: 2019-09-30 Impact factor: 7.422
Authors: Kristian Karstoft; Kamilla Winding; Sine H Knudsen; Noemi G James; Maria M Scheel; Jesper Olesen; Jens J Holst; Bente K Pedersen; Thomas P J Solomon Journal: Diabetologia Date: 2014-08-07 Impact factor: 10.122