title: High- and low-affinity binding sites for vasoactive intestinal peptide (VIP) in the rat kidney revealed by light microscopic autoradiography.
abstract: The distribution of VIP binding sites in rat kidney and adrenal gland has been examined by light microscopic autoradiography. A fully characterized mono-iodinated molecular form of VIP (M-125-I-VIP) which maintains the biological activity of the native peptide, was used for this study. Two types of VIP binding sites, with high and low affinity, have been identified. High affinity sites are associated with (i) glomerular structures in the cortex, (ii) the inner stripe of the outer medulla, possibly corresponding to Henle's loops and distal tubules, (iii) radiated structures in the inner zone of the medulla, likely to represent labeling of collecting ducts and/or vascular bundles and (iv) the adrenal cortex. Autoradiographic grains associated with low affinity sites are present diffusely throughout the renal cortex, possibly corresponding to labeling of tubular and/or vascular structures, and throughout the adrenal gland. These observations further delineate a role of VIP in renal and neuroendocrine function.
authors.affiliation: Department of Pharmacology, University Medical Center, Geneva, Switzerland.
authors.forename: P J
authors.initials: PJ
authors.lastname: Magistretti
authors.forename: P R
authors.initials: PR
authors.lastname: Hof
authors.forename: J L
authors.initials: JL
authors.lastname: Martin
authors.forename: M
authors.initials: M
authors.lastname: Dietl
authors.forename: J M
authors.initials: JM
authors.lastname: Palacios
mesh_terms: D000818:Animals; D001345:Autoradiography; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D007678:Kidney Glomerulus / Q000032:analysis*; D007679:Kidney Medulla / Q000032:analysis*; D008297:Male; D051381:Rats; D011964:Receptors, Gastrointestinal Hormone / Q000032:analysis*; D018005:Receptors, Vasoactive Intestinal Peptide; D014660:Vasoactive Intestinal Peptide / Q000032:analysis*
chemical_list: D007457:Iodine Radioisotopes; D011964:Receptors, Gastrointestinal Hormone; D018005:Receptors, Vasoactive Intestinal Peptide; D014660:Vasoactive Intestinal Peptide