Solubilization and characterization of [3H]imipramine and [3H]paroxetine binding sites from calf striatum.
The serotonin (5-HT) transporter from calf striatum cerebral membranes was solubilized with digitonin and characterized by gel exclusion chromatography. [3H]Imipramine and [3H]paroxetine were utilized as markers for labeling it. 3H-imipramine labels a high- and a low-affinity site on striatum membranes, whereas it binds to a single high-affinity site on the solubilized fraction. [3H]Paroxetine binds with the same affinity to a single site on both membranes and solubilized preparations. After gel exclusion chromatography of the solubilizate both [3H]imipramine and [3H]paroxetine bind on an identical fraction of 205 kDa molecular weight, with a similar maximum number of binding sites (Bmax). Our results suggest that both 3H-imipramine and [3H]paroxetine bind to a common site on the 5-HT transporter.
Rotondo
A
A
Institute of Psychiatry, University of Pisa, Italy.
Giannaccini
G
G
Quattrone
C
C
Marazziti
D
D
Martini
C
C
Cassano
G B
GB
Lucacchini
A
A
D000818:Animals; D002352:Carrier Proteins / Q000032:analysis*; D002417:Cattle; D003342:Corpus Striatum / Q000737:chemistry*; D007099:Imipramine; D008562:Membrane Glycoproteins / Q000032:analysis; D026901:Membrane Transport Proteins; D008566:Membranes / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000032:analysis; D017374:Paroxetine; D011955:Receptors, Drug / Q000032:analysis*; D012701:Serotonin; D050486:Serotonin Plasma Membrane Transport Proteins; D012995:Solubility; D014316:Tritium
D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D011955:Receptors, Drug; D050486:Serotonin Plasma Membrane Transport Proteins; C027775:imipramine receptor; C092604:paroxetine receptor; D014316:Tritium; D012701:Serotonin; D017374:Paroxetine; D007099:Imipramine