title: Characteristics of [3H]E-643-binding to alpha adrenoceptors.
abstract: Radiolabeled E-643, a newly developed antihypertensive compound, bound specifically to a preparation obtained from rat brain with a maximum of 85 f moles of binding sites per mg protein and a dissociation constant of 0.59 nM. Prazosin markedly inhibited the binding. While yohimbine and clonidine were only weak inhibitors. Other characteristics of the binding of [3H]E-643 to the brain and its specific binding to preparations of peripheral rat organs were also studied. The present findings suggest that [3H]E-643 is useful for labeling alpha 1-adrenoceptors.
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000378:metabolism; D000317:Adrenergic alpha-Antagonists / Q000378:metabolism*; D000818:Animals; D000959:Antihypertensive Agents / Q000378:metabolism*; D001665:Binding Sites; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D011485:Protein Binding; D011799:Quinazolines / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000378:metabolism*; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*; D013696:Temperature; D014316:Tritium
chemical_list: D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D000959:Antihypertensive Agents; D011799:Quinazolines; D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D014316:Tritium; C018176:bunazosin