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Down-regulation of platelet imidazoline-1-binding sites after bupropion treatment
- Source :
- The International Journal of Neuropsychopharmacology. 5
- Publication Year :
- 2002
- Publisher :
- Oxford University Press (OUP), 2002.
-
Abstract
- An elevation of I1 (imidazoline-1)-binding sites on platelets may be a state marker for depression. Herein, platelet I1 sites were compared in two groups of unipolar depressed patients given different regimens of bupropion treatment: Regimen 1 (n = 13 titrated up to 300 mg/d by week 4 and held constant until week 6); Regimen 2 (n = 15 titrated up to 300 mg/d by week 2, to 450 mg/d by week 6, and held constant until week 8). Platelet I1 sites were quantified by p-[125I]iodoclonidine binding (0.5-15 nM) and displaced by moxonidine under a saturating concentration of norepinephrine to mask alpha2-adrenoceptors. I1 B max values were confirmed to be high at pretreatment in depressed patients (n = 28) compared to healthy control subjects (n = 18; p = 0.02). Highest B max values at pretreatment were found in patients who responded worst to treatment. More than two-thirds of patients recovered from depression (69 and 80% in Regimens 1 and 2, respectively) after treatment. Dose and/or time of exposure to bupropion were relevant variables since (1). only Regimen 2 led to platelet I1 down-regulation and (2). the extent of down-regulation correlated with plasma concentrations of bupropion. The data suggest a dissociation exists between I1 down-regulation and therapeutic response, or else platelet I1 down-regulation lags behind clinical antidepressant response before becoming measurable.
- Subjects :
- Blood Platelets
medicine.medical_specialty
Time Factors
Adrenergic receptor
Receptors, Drug
Down-Regulation
Imidazoline receptor
Pharmacology
Clonidine
Norepinephrine (medication)
Internal medicine
medicine
Humans
Pharmacology (medical)
Platelet
Bupropion
Psychiatric Status Rating Scales
Depressive Disorder
Binding Sites
Moxonidine
Dose-Response Relationship, Drug
business.industry
Psychiatry and Mental health
Regimen
Endocrinology
Antidepressive Agents, Second-Generation
Antidepressant
Imidazoline Receptors
business
medicine.drug
Subjects
Details
- ISSN :
- 14695111 and 14611457
- Volume :
- 5
- Database :
- OpenAIRE
- Journal :
- The International Journal of Neuropsychopharmacology
- Accession number :
- edsair.doi.dedup.....529cf70b9b800f9b0550ee86aba24b63