Table 1.
Dopamine is the preferred endogenous agonist for the DD2Rs
| Ligand
|
pEC50 | ||
|---|---|---|---|
| DD2R-606 | DD2R-506 | DD2R-461 | |
| Dopamine | 6.3 ± 0.2 | 6.4 ± 0.1 | 6.3 ± 0.1 |
| Serotonin | 5.9 ± 0.0 | 5.6 ± 0.1 | 5.3 ± 0.1 |
| Norepinephrine | 5.7 ± 0.1 | 5.7 ± 0.3 | 5.6 ± 0.1 |
| Epinephrine | 5.7 ± 0.1 | 5.6 ± 0.1 | 5.5 ± 0.1 |
| Tyramine | 5.4 ± 0.1 | 5.2 ± 0.1 | 4.8 ± 0.2 |
HEK293 cells were cotransfected with receptor cDNA in addition to an SRE5x-luciferase reporter construct and an expression plasmid encoding the chimeric G protein Gq5i. After stimulation for 3 h in the absence or presence of increasing concentrations of biogenic amines, luciferase activity was assessed as described in Materials and Methods. Agonist pEC50 values are shown as the mean ± SEM from at least four independent experiments. Statistical analysis was performed by one-way ANOVA with Tukey–Kramer multiple comparisons post tests (vs. corresponding dopamine values).
*
, P < 0.05;
**
, P < 0.01;
, P < 0.001.