title: High-affinity [3H]6-nitroquipazine binding to the 5-hydroxytryptamine transport system in rat lung.
abstract: [3H]6-Nitroquipazine bound to rat lung membranes at 37 degrees with a dissociation constant (Kd) of 0.310 +/- 0.13 nM and a maximal number of binding sites (Bmax) of 1752 +/- 334 fmol/mg protein (mean +/- SD, N = 4). The binding was saturable, of high affinity and sodium dependent. Drug inhibition studies indicated that [3H]6-nitroquipazine binding in the lung is similar to that already reported in the rat brain and human platelets. Scatchard analysis indicated that 5-hydroxytryptamine (5-HT) inhibited [3H]6-nitroquipazine binding to rat lung membranes in a competitive manner. The present results suggest that [3H]6-nitroquipazine binding sites in the rat lung are associated with the uptake system of 5-HT.
authors.affiliation: Department of Radiopharmaceutical Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences, University of Fukuyama, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Hashimoto
authors.forename: T
authors.initials: T
authors.lastname: Goromaru
mesh_terms: D000818:Animals; D001692:Biological Transport; D003891:Desipramine / Q000494:pharmacology; D007099:Imipramine / Q000494:pharmacology; D007700:Kinetics; D008168:Lung / Q000378:metabolism*; D008297:Male; D008376:Maprotiline / Q000494:pharmacology; D008566:Membranes / Q000378:metabolism; D011814:Quipazine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*; D013237:Stereoisomerism; D013696:Temperature; D014316:Tritium; D015031:Zimeldine / Q000494:pharmacology
chemical_list: D014316:Tritium; D008376:Maprotiline; D012701:Serotonin; D015031:Zimeldine; D011814:Quipazine; C031227:6-nitroquipazine; D007099:Imipramine; D003891:Desipramine