Gastrin-releasing peptide stimulates glycoconjugate release from feline trachea.
The effect of gastrin-releasing peptide (GRP) on respiratory glycoconjugate (RGC) secretion was investigated in a feline tracheal organ culture model. RGC secretion was stimulated by GRP in a dose-dependent fashion at concentrations from 10(-8) to 10(-5) M (range 15-38% increase above control) with a peak effect within 0.5-1 h of incubation. GRP-(14-27), the receptor binding portion of GRP, and the related molecule, bombesin, also stimulated RGC secretion by approximately 20% above control. Acetyl-GRP-(20-27) stimulated RGC release by 10%, whereas GRP-(1-16) was inactive. Autoradiographic studies with 125I-GRP revealed that specific binding was restricted to the submucosal glands and the surface epithelium. A specific radioimmunoassay showed the content of GRP in feline trachea after extraction with ethanol-acetic acid to be 156 +/- 91 fmol/g wet wt. Indirect immunohistochemistry indicated that ganglion cells located just outside the cartilage contained GRP-immunoreactive materials. GRP is a novel mucus secretagogue that may participate in regulating airway mucosal gland secretion.
Critical Care Medicine Department, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
J D
JD
Lundgren
J N
JN
Baraniuk
N L
NL
Ostrowski
M A
MA
Kaliner
J H
JH
Shelhamer
D000818:Animals; D007611:Aprotinin / Q000494:pharmacology; D001345:Autoradiography; D001839:Bombesin / Q000494:pharmacology; D002415:Cats; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D019886:Gastrin-Releasing Peptide; D005768:Gastrointestinal Hormones / Q000494:pharmacology*; D006001:Glycoconjugates / Q000378:metabolism*; D007457:Iodine Radioisotopes; D007700:Kinetics; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism*; D009924:Organ Culture Techniques; D010446:Peptide Fragments / Q000494:pharmacology; D010455:Peptides / Q000378:metabolism / Q000494:pharmacology*; D018004:Receptors, Bombesin; D017981:Receptors, Neurotransmitter / Q000378:metabolism; D013329:Structure-Activity Relationship; D014132:Trachea / Q000187:drug effects / Q000378:metabolism*
D005768:Gastrointestinal Hormones; D006001:Glycoconjugates; D007457:Iodine Radioisotopes; D010446:Peptide Fragments; D010455:Peptides; D018004:Receptors, Bombesin; D017981:Receptors, Neurotransmitter; D019886:Gastrin-Releasing Peptide; D007611:Aprotinin; D001839:Bombesin