Endurance training effects on striatal D2 dopamine receptor binding and striatal dopamine metabolite levels (1987)
Comments: Study shows that long term endurance training can increase dopamine D2 receptors in the reward circuitry (striatum). D2 receptors decrease with addictions, and are a major part of desensitization.
FULL STUDY - Neurosci Lett. 1987 Aug 18;79(1-2):138-44.
MacRae PG, Spirduso WW, Cartee GD, Farrar RP, Wilcox RE.
Department of Health and Physical Education, College of Pharmacy, University of Texas, Austin 78712.
We have previously shown that endurance training is associated with higher binding of [3H]spiperone to striatal D2 dopamine (DA) receptors of presenescent (21 months old) rats. In the present study we investigated the effects of 6 months of endurance training of young adults on the relationship between steady-state levels of DA and its metabolites in striatum and the affinity and density of striatal D2 DA receptors. The extent of training was confirmed by evaluating the maximal oxygen consumption (VO2 max) in the subjects. D2 DA binding was significantly increased at each of 3 [3H]spiperone concentrations in the young runners. A 'synaptic coupling ratio' calculated as the specific DA binding/DOPAC concentration was significantly increased in runners for the 0.1 and 0.4 nM radioligand concentrations. Across experimental groups levels of DA were highly and positively correlated with specific DA binding at the 0.1, 0.2 and 0.4 nM [3H]spiperone concentrations. Together, these results suggest that exercise can alter the number of DA binding sites and the metabolism of DA in young adult animals.