Atypical beta-adrenoceptor in bovine adrenal medulla.
Bovine adrenal medullary membranes were incubated with [125I]cyanopindolol to assess beta-adrenoceptor binding. Binding was saturable and specific; a single low affinity site (Kd = 750 pM) was identified. [125I]Cyanopindolol binding was displaced by micromolar concentrations of classic beta-adrenoceptor antagonists and by sodium-4-[-2-[2-hydroxy-2-(-3-chloro-phenyl) ethylamino] propyl] phenoxyacetate. These data are similar to reported binding of beta 3-adrenoceptors and may explain beta-adrenoceptor agonist modulation of chromaffin cell degranulation in this catecholamine rich environment.
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21287-7294.
K
K
Clarkson
J R
JR
Tobin
M J
MJ
Breslow
D000313:Adrenal Medulla / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000318:Adrenergic beta-Agonists / Q000378:metabolism / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D001667:Binding, Competitive; D002417:Cattle; D015550:Cell Degranulation / Q000187:drug effects; D010869:Pindolol / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D011869:Radioligand Assay; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism*
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D011943:Receptors, Adrenergic, beta; C047975:cyanopindolol; D010869:Pindolol