title: Autoradiographic visualization of muscarinic receptors in human bronchi.
abstract: To visualize muscarinic receptors in human bronchi, the stripping film method was used which permits direct autoradiographic localization of tissue labeling. Cryostate sections of human bronchi were fixed in 0.5% glutaraldehyde in Krebs-Ringer buffer, pH 7.0 for 30 min at 0 degrees C, washed in Krebs-Ringer buffer for 20 min at 0 degrees C and incubated with (-)-[3H]Quinuclidinyl benzilate [(-)-[3H]QNB] for 90 min at 37 degrees C. Specific (-)-[3H]QNB binding to tissue sections was saturable (receptor density of 0.14 +/- 0.03 fmol/tissue section) and of high affinity (Kd of 40 +/- 9 pM). For autoradiography, labeled tissue sections were covered with stripping film and exposed for 5 months. Muscarinic receptors in human bronchi were located predominantly in submucosal glands and parasympathetic ganglia. There was less labeling in smooth muscle cells and nerve bundles. Epithelium and blood vessels located within the bronchial wall were devoid of specific labeling.
authors.affiliation: Department of Pharmacology, University of Nijmegen, The Netherlands.
authors.forename: C J
authors.initials: CJ
authors.lastname: van Koppen
authors.forename: W M
authors.initials: WM
authors.lastname: Blankesteijn
authors.forename: A B
authors.initials: AB
authors.lastname: Klaassen
authors.forename: J F
authors.initials: JF
authors.lastname: Rodrigues de Miranda
authors.forename: A J
authors.initials: AJ
authors.lastname: Beld
authors.forename: C A
authors.initials: CA
authors.lastname: van Ginneken
mesh_terms: D000368:Aged; D001345:Autoradiography; D001980:Bronchi / Q000032:analysis*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D011976:Receptors, Muscarinic / Q000032:analysis* / Q000502:physiology; D014316:Tritium
chemical_list: D011976:Receptors, Muscarinic; D014316:Tritium; D011813:Quinuclidinyl Benzilate