title: Sex differences in striatal dopamine D2/D3 receptor availability in smokers and non-smokers.
abstract: In previous research, nicotine-dependent men exhibited lower putamen D2/D3 dopamine-receptor availability than non-smokers (Fehr et al. 2008), but parallel assessments were not performed in women. Women and men (19 light smokers, 18 non-smokers) were tested for differences due to sex and smoking in striatal D(2)/D(3) dopamine-receptor availability, using positron emission tomography with [(18)F]fallypride. Receptor availability was determined using a reference region method, in striatal volumes and in whole-brain, voxel-wise analysis. Significant sex × smoking interactions were observed in the caudate nuclei and putamen. Post-hoc t tests showed that male smokers had significantly lower D(2)/D(3) dopamine-receptor availability than female smokers (-17% caudate, -21% putamen) and male non-smokers (-15% caudate, -16% putamen). Female smokers did not differ from non-smokers. Whole-brain analysis demonstrated no statistically significant voxels or clusters. These results suggest that low receptor availability may confer vulnerability to nicotine dependence or that smoking selectively affects D2/D3 receptor down-regulation in men but not women.
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, UCLA, Los Angeles, CA, USA.
authors.forename: Amira K
authors.initials: AK
authors.lastname: Brown
authors.forename: Mark A
authors.initials: MA
authors.lastname: Mandelkern
authors.forename: Judah
authors.initials: J
authors.lastname: Farahi
authors.forename: Chelsea
authors.initials: C
authors.lastname: Robertson
authors.forename: Dara G
authors.initials: DG
authors.lastname: Ghahremani
authors.forename: Brittany
authors.initials: B
authors.lastname: Sumerel
authors.forename: Nathasha
authors.initials: N
authors.lastname: Moallem
authors.forename: Edythe D
authors.initials: ED
authors.lastname: London
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001549:Benzamides / Q000493:pharmacokinetics; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050637:Receptors, Dopamine D3 / Q000378:metabolism*; D012727:Sex Characteristics; D012907:Smoking / Q000473:pathology*; D055815:Young Adult
chemical_list: D001549:Benzamides; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D019788:Fluorodeoxyglucose F18; C574003:fallypride