The Effect of Treatment with Guanfacine, an Alpha2 Adrenergic Agonist, on Dopaminergic Tone in Tobacco Smokers: An [11C]FLB457 PET Study.
Neuropsychopharmacology
; 43(5): 1052-1058, 2018 04.
Article
em En
| MEDLINE
| ID: mdl-28944773
ABSTRACT
Guanfacine, a noradrenergic alpha2a agonist, reduced tobacco smoking in a 4-week trial and in animal models has been shown to reduce cortical dopamine release, which is critically involved in the reinforcing effect of tobacco smoking. We measured amphetamine-induced extrastriatal dopamine release before and after treatment with guanfacine with [11C]FLB457, a dopamine D2/D3 receptor radiotracer, and positron emission tomography (PET). Sixteen tobacco smokers had one set of [11C]FLB457 PET scans on the same day, one before and one at 2.5-3 h after amphetamine (0.4-0.5 mg/kg, PO). A subset (n=12) then underwent guanfacine treatment (3 mg/day for 3 weeks) and the set of scans were repeated. [11C]FLB457-binding potential (BPND) was measured pre- and post amphetamine in extrastriatal brain regions. The fractional change in BPND after vs before amphetamine (Δ BPND) is an indirect measure of DA release and was compared between the untreated and guanfacine-treated conditions. Guanfacine treatment attenuated amphetamine-induced DA release; however, the change was due to a global 8% decrease in baseline BPND from the untreated to the guanfacine-treated condition. Chronic guanfacine treatment reduced [11C]FLB457 BPND in tobacco smokers, suggesting an increase in dopaminergic tone. Guanfacine-induced normalization of dopamine signaling may be an important mesocortical mechanism contributing to its ability to aid in tobacco smoking cessation.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pirrolidinas
/
Dopamina
/
Salicilamidas
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Guanfacina
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Tomografia por Emissão de Pósitrons
/
Agonistas de Receptores Adrenérgicos alfa 2
/
Fumantes
Tipo de estudo:
Prognostic_studies
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Neuropsychopharmacology
Assunto da revista:
NEUROLOGIA
/
PSICOFARMACOLOGIA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Estados Unidos