Sunshine-exposure variation of human striatal dopamine D(2)/D(3) receptor availability in healthy volunteers.
BACKGROUND
In addition to the serotonergic system, the central dopaminergic system has been reported to be correlated with seasonality. The aim of this study was to explore the difference in striatal dopamine D(2)/D(3) receptor availability between healthy volunteers who had a high-sunshine exposure and those who had a low exposure.


METHODS
Sixty-eight participants were enrolled, and those in the upper and lower quartiles in terms of sunshine exposure were categorized into high- (n = 17) and low-sunshine-exposure (n = 18) subgroups. Single photon emission computed tomography with [(123)I] iodo-benzamide was used to measure striatal dopamine D(2)/D(3) receptor availability.


RESULTS
Striatal dopamine D(2)/D(3) receptor availability was significantly greater in the subjects with high-sunshine exposure than in those with low-sunshine exposure (F = 7.97, p = 0.01) after controlling for age, sex, and smoking status.


CONCLUSIONS
Different subjects were examined at different time points in our study. In addition, the sex and tobacco use distributions differed between groups.


CONCLUSIONS
The central dopaminergic system may play a role in the neurobiological characteristics of sunshine-exposure variation.
Tsai
Hsiang-Yi
HY
Department of Psychiatry, St Martin De Porres Hospital, Chiayi, Taiwan.
Chen
Kao Chin
KC
Yang
Yen Kuang
YK
Chen
Po See
PS
Yeh
Tzung Lieh
TL
Chiu
Nan Tsing
NT
Lee
I Hui
IH
D000328:Adult; D000704:Analysis of Variance; D001549:Benzamides / Q000493:pharmacokinetics; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011485:Protein Binding / Q000187:drug effects; D011759:Pyrrolidines / Q000493:pharmacokinetics; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050637:Receptors, Dopamine D3 / Q000378:metabolism*; D012189:Retrospective Studies; D012621:Seasons; D013472:Sunlight; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D055815:Young Adult
D001549:Benzamides; D018492:Dopamine Antagonists; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide