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Title: Autoradiographic localization of calcitonin gene-related peptide (CGRP) binding sites in human and guinea pig lung

Journal Article · · Peptides (Fayetteville, N.Y.); (United States)

/sup 125/I-Human calcitonin gene-related peptide (hCGRP) binding sites were localized in human and guinea pig lungs by an autoradiographic method. Scatchard analysis of saturation experiments from slide-mounted sections of guinea pig lung displayed specific /sup 125/I-hCGRP binding sites with a dissociation constant (Kd) of 0.72 +/- 0.05 nM (mean +/- S.E.M., n = 3) and a maximal number of binding sites (Bmax) of 133.4 +/- 5.6 fmol/mg protein. In both human and guinea pig lung, autoradiography revealed that CGRP binding sites were widely distributed, with particularly dense labeling over bronchial and pulmonary blood vessels of all sizes and alveolar walls. Airway smooth muscle and epithelium of large airways was sparsely labeled but no labeling was found over submucosal glands. This localization corresponds well to the reported pattern of CGRP-like immunoreactive innervation. The findings of localization of CGRP binding sites on bronchial and pulmonary blood vessels indicate that CGRP may be important in the regulation of airway and pulmonary blood flow.

Research Organization:
National Heart and Lung Institute, London (England)
OSTI ID:
6080148
Journal Information:
Peptides (Fayetteville, N.Y.); (United States), Vol. 9:5
Country of Publication:
United States
Language:
English