GLP-1 stimulates secretion of macromolecules from airways and relaxes pulmonary artery.
Recent data revealed the existence of specific receptors for glucagon-like peptide-1(7-36)amide (GLP-1) on rat lung membranes. Utilizing slide-mount autoradiography of fresh frozen lung tissue sections, we have localized binding sites for GLP-1 on mucous glands in the trachea and on vascular smooth muscle of the pulmonary artery. When tracheas were incubated in a modified Ussing chamber, the addition of GLP-1 to the submucosal side increased 35S-sulfate-labeled macromolecule secretion (191 +/- 12% above basal, P < 0.005). The optimal secretory response elicited by GLP-1 was approximately 23% of the maximal secretory response after a maximal acetylcholine stimulation. Other proglucagon-derived peptides such as glucagon, oxyntomodulin, and GLP-2 had no effect. In isolated rings of arteries, GLP-1 (10(-8) to 10(-5) M) induced a dose-dependent and time-reversible relaxation of preconstricted arteries. In a preparation with denuded epithelium, GLP-1 lost its effect. In conclusion, GLP-1 might represent another neuropeptide that acts as neurotransmitter of the peptidergic, nonadrenergic-noncholinergic nervous system that innervates the airways.
Richter
G
G
Department of Internal Medicine, Philipps University of Marburg, Germany.
Feddersen
O
O
Wagner
U
U
Barth
P
P
Göke
R
R
Göke
B
B
D000818:Animals; D001345:Autoradiography; D005934:Glucagon / Q000378:metabolism / Q000494:pharmacology*; D052216:Glucagon-Like Peptide 1; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008297:Male; D009093:Mucus / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*; D011498:Protein Precursors / Q000378:metabolism / Q000494:pharmacology*; D011651:Pulmonary Artery / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014132:Trachea / Q000378:metabolism*; D014664:Vasodilation
D046911:Macromolecular Substances; D010446:Peptide Fragments; D011498:Protein Precursors; D052216:Glucagon-Like Peptide 1; D005934:Glucagon