title: Azidomorphine is an agonist of high-affinity opioid receptor binding sites.
abstract: Azidomorphine at low concentration (10(-9) M) inhibits the high-affinity binding site of labeled naloxone in rat brain membrane preparations. In the presence of Na+ and guanine nucleotides the displacement curves of azidomorphine are increased toward high concentrations, whereas Mg2+ ions decrease the IC50 values; This demonstrates the agonist behavior of azidomorphine in binding experiments. When compared with morphine, azidomorphine displayed five-fold lower IC50 values. Based on the presented results, azidomorphine appears to be a good candidate for photoaffinity labeling of opiate receptors.
authors.affiliation: Institute of Biochemistry Biological Research Center of Hungarian Academy of Sciences, Szeged.
authors.forename: K
authors.initials: K
authors.lastname: Horváth
authors.forename: M
authors.initials: M
authors.lastname: Wollemann
mesh_terms: D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D004090:Dihydromorphine / Q000378:metabolism; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007700:Kinetics; D009020:Morphine / Q000494:pharmacology; D009022:Morphine Derivatives / Q000494:pharmacology*; D009270:Naloxone / Q000378:metabolism; D051381:Rats; D011957:Receptors, Opioid / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000700:Analgesics; D009022:Morphine Derivatives; D011957:Receptors, Opioid; C006659:azidomorphine; D006165:Guanylyl Imidodiphosphate; D009270:Naloxone; D009020:Morphine; D004090:Dihydromorphine