Background: Mesolimbic and nigrostriatal dopaminergic pathways play important roles in both the rewarding and
conditioning effects of drugs. The dopamine transporter (DAT) is of central importance in regulating dopaminergic
neurotransmission and in particular in activating the striatal D2-like receptors. Molecular imaging studies of the
relationship between DAT availability/dopamine synthesis capacity and active cigarette smoking have shown
conflicting results. Through the collaboration between 13 SPECT centres located in 10 different European countries,
a database of FP-CIT-binding in healthy controls was established. We used the database to test the hypothesis that
striatal DAT availability is changed in active smokers compared to non-smokers and ex-smokers.
Methods: A total of 129 healthy volunteers were included. Subjects were divided into three categories according
to past and present tobacco smoking: (1) non-smokers (n = 64), (2) ex-smokers (n = 39) and (3) active smokers
(n = 26). For imaging of the DAT availability, we used [123I]FP-CIT (DaTSCAN) and single photon emission computed
tomography (SPECT). Data were collected in collaboration between 13 SPECT centres located in 10 different
European countries. The striatal measure of DAT availability was analyzed in a multiple regression model with age,
SPECT centre and smoking as predictor.
Results: There was no statistically significant difference in DAT availability between the groups of active smokers,
ex-smokers and non-smokers (p = 0.34). Further, we could not demonstrate a significant association between
striatal DAT and the number of cigarettes per day or total lifetime cigarette packages in smokers and ex-smokers.
Conclusion: Our results do not support the hypothesis that large differences in striatal DAT availability are present
in smokers compared to ex-smokers and healthy volunteers with no history of smoking.
Keywords: Tobacco smoking, Non-smoking, SPECT, [123I]FP-CIT (DaTSCAN), Dopamine transporter
