In:
American Journal of Physiology-Endocrinology and Metabolism, American Physiological Society, Vol. 273, No. 5 ( 1997-11-01), p. E981-E988
Abstract:
Glucagon-like peptide 1 (GLP-1) has been shown to inhibit gastric emptying of liquid meals in type 2 diabetic patients. It was the aim of the present study to compare the action of physiological and pharmacological doses of intravenous GLP-1-(7—36) amide and GLP-1-(7—37) on gastric emptying in normal volunteers. Nine healthy subjects participated (26 ± 3 yr; body mass index 22.9 ± 1.6 kg/m 2 ; hemoglobin A 1C 5.0 ± 0.2%) in five experiments on separate occasions after an overnight fast. A nasogastric tube was positioned for the determination of gastric volume by use of a dye-dilution technique (phenol red). GLP-1-(7—36) amide (0.4, 0.8, or 1.2 pmol ⋅ kg −1 ⋅ min −1 ), GLP-1-(7—37) (1.2 pmol ⋅ kg −1 ⋅ min −1 ), or placebo was infused intravenously from −30 to 240 min. A liquid meal (50 g sucrose, 8% amino acids, 440 ml, 327 kcal) was administered at 0 min. Glucose, insulin, and C-peptide were measured over 240 min. Gastric emptying was dose dependently slowed by GLP-1-(7—36) amide ( P 〈 0.0001). Effects of GLP-1-(7—37) at 1.2 pmol ⋅ kg −1 ⋅ min −1 were virtually identical. GLP-1 dose dependently stimulated fasting insulin secretion (−30 to 0 min) and slightly reduced glucose concentrations. After the meal (0–240 min), integrated incremental glucose ( P 〈 0.0001) and insulin responses ( P = 0.01) were reduced (dose dependently) rather than enhanced. In conclusion, 1) GLP-1-(7—36) amide or -(7—37) inhibits gastric emptying also in normal subjects, 2) physiological doses (0.4 pmol ⋅ kg −1 ⋅ min −1 ) still have a significant effect, 3) despite the known insulinotropic actions of GLP-1-(7—36) amide and -(7—37), the net effect of administering GLP-1 with a meal is no change or a reduction in meal-related insulin responses. These findings suggest a primarily inhibitory function for GLP-1 (ileal brake mechanisms).
Type of Medium:
Online Resource
ISSN:
0193-1849
,
1522-1555
DOI:
10.1152/ajpendo.1997.273.5.E981
Language:
English
Publisher:
American Physiological Society
Publication Date:
1997
detail.hit.zdb_id:
1477331-4
SSG:
12
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