Autoradiographic localisation of VIP receptors in human lung

Abstract
Localisation and pharmacological properties of the VIP receptor in human lung sections are described. The receptor density determined by saturation analysis using 125I‐VIP is approx. 100 protein, with a k d of approx. 600 pM. Inhibition of 125I‐VIP binding with VIP and related peptides gives a rank order of potency: VIP /s> peptide histidine methionine /s> secretin. Light microscope autoradiography reveals specific VIP binding sites, with a high density over the pulmonary artery smooth muscle and the alveolar walls and with a lower density over the bronchial epithelium.