title: Low density and high affinity of platelet [3H]paroxetine binding in women with bulimia nervosa.
abstract: Impaired serotonin transmission has been suggested to be implicated in the pathophysiology of bulimia nervosa. As an indirect measure of brain serotonergic activity, the binding of tritiated ligands to platelet serotonin transporters has been studied in bulimia nervosa as well as in other putatively serotonin-related psychiatric disorders. In this study, the density and affinity of platelet serotonin transporters were assessed in 20 women meeting the DSM-IV criteria for bulimia nervosa and in 14 controls without previous or ongoing eating disorder using [(3)H]paroxetine as a ligand. In comparison to controls, women with bulimia nervosa had a significantly reduced number of platelet binding sites (B(max) = 721 +/- 313 vs. 1145 +/- 293 fmol/mg protein) and an increase in the affinity for the ligand demonstrated by a lower dissociaton constant (K(d) = 33 +/- 10 vs. 44 +/- 10 pM). A significant correlation between B(max) and K(d) values was found in patients but not in controls. Our results support the notion that bulimia nervosa is associated with a reduction in platelet serotonin transporter density. In addition, our study is the first to report that this reduced transporter density in women with bulimia nervosa is accompanied by an increase in the affinity of the transporter for the ligand.
authors.affiliation: Department of Pharmacology, Göteborg University, Sweden. agneta.ekman@pharm.gu.se
authors.forename: Agneta
authors.initials: A
authors.lastname: Ekman
authors.forename: Charlotta
authors.initials: C
authors.lastname: Sundblad-Elverfors
authors.forename: Mikael
authors.initials: M
authors.lastname: Landén
authors.forename: Tomas
authors.initials: T
authors.lastname: Eriksson
authors.forename: Elias
authors.initials: E
authors.lastname: Eriksson
mesh_terms: D000328:Adult; D001792:Blood Platelets / Q000378:metabolism*; D001921:Brain / Q000503:physiopathology; D002032:Bulimia / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D017374:Paroxetine / Q000493:pharmacokinetics*; D011869:Radioligand Assay; D012016:Reference Values; D012701:Serotonin / Q000502:physiology; D050486:Serotonin Plasma Membrane Transport Proteins / Q000502:physiology*; D014316:Tritium
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins; D014316:Tritium; D012701:Serotonin; D017374:Paroxetine