title: [A radioreceptor assay for catecholamines. I. A study with 3H-norepinephrine (author's transl)].
abstract: A radioreceptor assay for catecholamines(CA) has been established utilizing the microsomal fraction of bovine myocardium as CA receptors and 3H-norepinephrine(3H-NA) as a ligand. The bound fraction was separated from the free fraction by filtration through milipore filters. The following results were obtained: 1) The optimal amount of the microsomal fraction was 250 micrograms/tube, when 3H-NA of 12,000 c.p.m was used. The appropriate conditions for incubation were 2 hours at 37 degrees C in a pH 7.4 sucrose solution. 2) By this method, norepinephrine was detectable in the range from 5 to 100ng/tube. 3) Various compounds with catechol nucleus showed a cross-reaction in this radioreceptor assay system. 4) Alpha-adrenergic blocking agents inhibited the binding of 3H-NA, whereas beta-blocking agents were ineffective. These results suggest that the microsomal fraction of bovine myocardium contains alpha-adrenergic receptors which bind the catechol nucleus of CA.
mesh_terms: D000818:Animals; D002395:Catecholamines / Q000097:blood*; D002417:Cattle; D009638:Norepinephrine; D011869:Radioligand Assay / Q000379:methods*; D014316:Tritium
chemical_list: D002395:Catecholamines; D014316:Tritium; D009638:Norepinephrine