EFFECTS OF GASTRIN-RELEASING PEPTIDE AND ANALOGS ON GUINEA-PIG NASAL MUCOSAL SECRETION

The effects of gastrin-releasing peptide (GRP), bombesin, GRP-(1 - 16) and GRP-(21-27) on guinea pig nasal mucosal secretion were studied in vivo. GRP, bombesin, and GRP-(21-27) induced significant secretion of total protein, albumin, and alkaline phosphatase. GRP induced signifi cant secretion at lower concentrations (10(-11) and 10(-10) M) than we re required for bombesin and GRP-(21-27) (10(-7) M). GRP-(1-16) did no t stimulate secretion, indicating that the COOH-terminal region of GRP contained the secretagogic principle. Capsaicin, a stimulant of nocic eptive sensory nerves, stimulated GRP release into nasal secretions. T hese data suggest that GRP is present in guinea pig nasal mucosa and t hat the COOH-terminal region of GRP may regulate mucosal macromolecule secretion.