Research Article
The Dopaminergic Reward System and Leisure Time Exercise Behavior: A Candidate Allele Study
Table 1
Allele-specific hypotheses.
| Gene | Variant | Allele | Expected effect | Reference number | Effect on dopamine level* | Effect on exercise behavior* |
| DRD1 | rs265981 | A | Decreased DRD1 expression levels | [24] | ↓ | ↓ | DRD2 | rs6275 | G | Increased DRD2 expression levels | [25] | ↓ | ↓ | rs1800497 | A | Reduced number of (inhibitory) D2 receptors | [28, 29] | ↑ | ↑ | DRD3 | rs6280 | C | Higher affinity for dopamine → decreased transmission | [31] | ↓ | ↓ | DRD4 | rs1800955 | C | Increased DRD4 expression levels | [32, 33] | ↓ | ↓ | VNTR: 7 allele | | Lower affinity for dopamine → increased transmission | [34, 35] | ↑ | ↑ | DRD5 | VNTR: 148 allele | | Decreased DRD5 expression levels | [36] | ↓ | ↓ | DBH | rs1611115 | C | Higher DBH activity | [37, 38] | ↓ | ↓ | rs2519152 | T | Lower DBH activity | [39] | ↑ | ↑ | DAT1 | VNTR: 480 allele | | Higher DAT activity → higher reuptake | [40, 41] | ↓ | ↓ | COMT | rs4680 | G | Methionine → slower degradation of dopamine | [42] | ↑ | ↑ |
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: increase; ↓: decrease.
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