COMT Val158Met Genotype Does Not Alter Cortical or Striatal Dopamine D2 Receptor Availability In Vivo
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Catechol-O-methyl transferase (COMT) is a pivotal regulator of brain dopamine function with a region-specific role. COMT is important in dopamine elimination in the prefrontal cortex, whereas dopamine reuptake is the main mechanism for synaptic removal of dopamine in the striatum. We studied whether the functional COMT gene polymorphism (Val158Met) associates with altered dopamine D2 receptor binding characteristics in vivo hypothesizing an effect in the cortex but not in the striatum.
Samples of 38 and 45 Finnish healthy subjects scanned previously with PET and the D2/D3 receptor radioligands [11C]FLB457 or [11C]raclopride, respectively, were genotyped for the Val158Met polymorphism.
No significant associations were found between the Val158Met genotype and D2 receptor binding characteristics in the cortex or the striatum as measured with [11C]FLB457 and [11C]raclopride, respectively.
COMT genotype is not related with alterations in baseline D2 receptor availability in vivo in the cortex or the striatum. This information is useful for the interpretation of genetic studies on COMT in neuropsychiatry.
Key wordsBinding potential Gene variation Human Neuropsychiatry Positron emission tomography
We gratefully acknowledge the staff of Turku PET Centre (Turku, Finland), the Radiopharmaceutical Chemistry Laboratory of University of Turku (Turku, Finland), and the Department of Pharmacology, Drug Development, and Therapeutics of University of Turku (Turku, Finland). This study has been supported financially by EVO-funding, Turku University Central Hospital (13649 to J.H. and 13464 for J.O.R.) and by personal research grants from Oy H. Lundbeck Ab (to M.M.H.) and from Research and Science Foundation of Farmos (to M.M.H.).
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