title: [3H]Epibatidine binding to bovine adrenal medulla: evidence for alpha3beta4* nicotinic receptors.
abstract: In these studies, [3H]epibatidine is used as the radioligand to characterize nicotinic acetylcholine receptors (nAChRs) from bovine adrenal medulla. Specific binding reaches equilibrium within 30 min, and is saturable with a Kd value of 0.5 nM. The affinities of several cholinergic agents were determined, including nicotine (Ki, 0.2 microM), cytisine (Ki, 0.4 microM), carbachol (Ki, 4.7 microM), dihydro-beta-erythrodine (Ki, 33.6 microM), D-tubocurarine (Ki, 0.4 microM), 1,1-dimethyl-4-phenyl-piperazinium (Ki, 0.8 microM), decamethonium (Ki, 234 microM) and methyllycaconitine (Ki, 1.3 microM). These values are similar to reported values for recombinant alpha3beta4 nAChRs in transfected cell lines. These studies demonstrate [3H]epibatidine binding to an easily obtainable adrenal membrane preparation and support the characterization of adrenal nAChRs as alpha3beta4* nAChRs.
authors.affiliation: Division of Pharmacology, The Ohio State University College of Pharmacy, 500 West 12th Avenue, Columbus, OH 43210, USA.
authors.forename: R Benjamin
authors.initials: RB
authors.lastname: Free
authors.forename: Darrell L
authors.initials: DL
authors.lastname: Bryant
authors.forename: Susan B
authors.initials: SB
authors.lastname: McKay
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Kaser
authors.forename: Dennis B
authors.initials: DB
authors.lastname: McKay
mesh_terms: D000313:Adrenal Medulla / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites / Q000187:drug effects / Q000502:physiology; D001667:Binding, Competitive / Q000187:drug effects / Q000502:physiology; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000378:metabolism*; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D018722:Nicotinic Agonists / Q000378:metabolism*; D018733:Nicotinic Antagonists / Q000378:metabolism; D011725:Pyridines / Q000378:metabolism*; D011869:Radioligand Assay; D011978:Receptors, Nicotinic / Q000378:metabolism*; D014316:Tritium
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D018722:Nicotinic Agonists; D018733:Nicotinic Antagonists; D011725:Pyridines; D011978:Receptors, Nicotinic; C403530:nicotinic receptor alpha3beta4; D014316:Tritium; C082748:epibatidine