Abstract
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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adrenal Medulla / cytology
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Adrenal Medulla / drug effects
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Adrenal Medulla / metabolism*
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Adrenergic beta-Agonists / metabolism
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Adrenergic beta-Agonists / pharmacology*
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Adrenergic beta-Antagonists / metabolism
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Adrenergic beta-Antagonists / pharmacology*
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Animals
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Binding, Competitive
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Cattle
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Cell Degranulation / drug effects
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Pindolol / analogs & derivatives
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Pindolol / metabolism
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Pindolol / pharmacology
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Radioligand Assay
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Receptors, Adrenergic, beta / drug effects
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Receptors, Adrenergic, beta / metabolism*
Substances
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Adrenergic beta-Agonists
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Adrenergic beta-Antagonists
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Receptors, Adrenergic, beta
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cyanopindolol
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Pindolol