title: Lymphocyte beta-adrenergic receptor modification in bulimia.
abstract: beta-Adrenergic receptor binding on circulating lymphocytes was evaluated in young female bulimic patients (n = 12) and age- and sex-matched normal control volunteers (n = 10). Using iodine 125-labeled cyanopindolol, antagonist binding was evaluated (number of receptors [Bmax] and dissociation constant [KD]), and using isoproterenol competition of cyanopindolol binding, the concentration required to inhibit binding by 50% (IC50) for isoproterenol and the agonist affinity measure of KL/KH (ratio of dissociation constants for the low- and high-affinity states of the receptor) were determined. Plasma norepinephrine (NE) level was also measured. There was a trend toward lower plasma NE levels in the bulimic patients. The KL/KH ratio in bulimic patients was significantly greater than that for the normal volunteers, indicating increased receptor coupling. The KL/KH ratio was not significantly correlated with plasma NE level. Neither Bmax nor KD was different between the two groups. These findings suggest that beta-adrenergic receptors in bulimic patients may be more responsive than in normal subjects, without alteration of the traditional measures of receptor responses, a difference that cannot be explained on the basis of plasma NE. These findings provide another line of evidence for altered regulation of the noradrenergic system in bulimic patients during a controlled phase of their illness.
authors.affiliation: Section on Clinical Pharmacology, National Institute of Mental Health, Bethesda, Md.
authors.forename: N S
authors.initials: NS
authors.lastname: Buckholtz
authors.forename: D T
authors.initials: DT
authors.lastname: George
authors.forename: A O
authors.initials: AO
authors.lastname: Davies
authors.forename: D C
authors.initials: DC
authors.lastname: Jimerson
authors.forename: W Z
authors.initials: WZ
authors.lastname: Potter
mesh_terms: D000328:Adult; D002032:Bulimia / Q000097:blood / Q000378:metabolism*; D005260:Female; D006165:Guanylyl Imidodiphosphate / Q000097:blood; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism*; D009638:Norepinephrine / Q000097:blood / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*
chemical_list: D011943:Receptors, Adrenergic, beta; D006165:Guanylyl Imidodiphosphate; D009638:Norepinephrine