title: High affinity binding of [3H]ethylketocyclazocine to rat brain homogenate.
abstract: Ethylketocyclazocine (Ekc), a potent kappa-receptor agonist, binds to opiate receptor sites in rat brain tissue. The binding was saturable with respect to the concentration of [3H]Ekc. The dissociation constant of Ekc-receptor complex was 1.8 nM and the maximum number of binding sites in the whole brain was 9.6 pmol/g of tissue. Opiate agonists and antagonists have a high affinity for [3H]Ekc binding sites, but results of present investigations failed to differentiate opiates thought to be specific for the mu- and kappa-receptors.
mesh_terms: D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D003496:Cyclazocine / Q000031:analogs & derivatives* / Q000378:metabolism; D016314:Ethylketocyclazocine; D007700:Kinetics; D008297:Male; D009294:Narcotics / Q000378:metabolism*; D051381:Rats; D011955:Receptors, Drug / Q000378:metabolism
chemical_list: D009294:Narcotics; D011955:Receptors, Drug; D016314:Ethylketocyclazocine; D003496:Cyclazocine