Decrease of the D4 dopamine receptor messenger RNA expression in lymphocytes from patients with major depression.
OBJECTIVE
The evaluation of the possible role of dopamine in psychiatric disorders has been limited by the relative inadequacy of tools. A tempting approach to examine alterations of dopaminergic system in major depression is to examine the expression of dopamine receptors in peripheral blood mononuclear cells (PBMC).


METHODS
D4 dopamine receptor (D4DR) messenger RNA (mRNA) expression in PBMC from 12 patients with major depressive disorder was examined before and after an 8-week treatment with paroxetine at 20-50 mg/day. Ten healthy subjects were analyzed in parallel. The relative content of D4DR mRNA was determined by reverse transcriptase-polymerase chain reaction (RT-PCR). using beta-actin as internal standard.


RESULTS
D4DR mRNA levels were significantly decreased in untreated depressed patients as compared to controls. D4DR mRNA expression returned to control levels after paroxetine treatment, when patients achieved a significant improvement of depressive symptoms.


CONCLUSIONS
Results of our study suggest the role of PBMC D4DR mRNA expression as a peripheral marker of the central dopaminergic function in major depression.
Rocc
Paola
P
Psychiatric Section, Department of Neuroscience, University of Turin, Via Cherasco 11, 10126 Turin, Italy. paola.rocca@unito.it
De Leo
Concetta
C
Eva
Carola
C
Marchiaro
Livio
L
Milani
Anna Maria
AM
Musso
Rita
R
Ravizza
Luigi
L
Zanalda
Enrico
E
Bogetto
Filippo
F
D000199:Actins / Q000096:biosynthesis; D000293:Adolescent; D000328:Adult; D000368:Aged; D018687:Antidepressive Agents, Second-Generation / Q000627:therapeutic use; D015415:Biomarkers; D003720:Densitometry; D003865:Major Depressive Disorder / Q000097:blood* / Q000188:drug therapy / Q000523:psychology; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism; D015345:Oligonucleotide Probes; D017374:Paroxetine / Q000627:therapeutic use; D011569:Psychiatric Status Rating Scales; D012333:RNA, Messenger / Q000096:biosynthesis*; D017448:Receptors, Dopamine D2 / Q000096:biosynthesis*; D050638:Receptors, Dopamine D4; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use
D000199:Actins; D018687:Antidepressive Agents, Second-Generation; D015415:Biomarkers; D015345:Oligonucleotide Probes; D017374:Paroxetine; D012333:RNA, Messenger; D017448:Receptors, Dopamine D2; D050638:Receptors, Dopamine D4; D017367:Selective Serotonin Reuptake Inhibitors; C493599:DRD4 protein, human