Table 1.
Activation of Gαi/o, Gβγ, heterologous sensitization, and DMR downstream of the DRD2. Gαi/o signaling and heterologous sensitization were measured in HEK-AC5/D2 cells. Activation of Gβγ signaling was measured in HEK-AC2/D2 cells and DMR was measured in HEK-D2 cells. EC50 values are shown in nM with the 95% confidence interval. The maximal effects are shown as percentages of dopamine’s response with standard errors. Data in the table represent the average of at least three independent experiments. ND = not determined.
| Gαi/o activation | Gβγ activation | Sensitization | DMR (AUC) | |||||
|---|---|---|---|---|---|---|---|---|
| Compound | EC50 (nM) | Max (%) | EC50 (nM) | Max (%) | EC50 (nM) | Max (%) | EC50 (nM) | Max (%) |
| Dopamine | 1.5 (0.6–3.7) | 100 (±3) | 46 (28–75) | 100 (±4) | 8.2 (5.5–12.2) | 100 (±3) | 7.6 (6.7–8.6) | 100 (±1) |
| Quinpirole | 2.1 (1.0–4.5) | 98 (±3) | 74 (50–109) | 99 (±4) | 8.2 (6.1–11.0) | 124 (±3) | 37 (32–44) | 104 (±1) |
| Aripiprazole | 4.1 (0.6–30) | 48 (±9) | ND | - | 1.6 (0.7–3.9) | 18 (±1) | 730 (433–1231) | 32 (±1) |
| Pramipexole | 0.9 (0.4–1.9) | 87 (±4) | 17 (7.7–36) | 98 (±5) | 1.9 (1.2–3.0) | 119 (±4) | 8.3 (5.8–12) | 98 (±2) |
| Ropinirole | 2.6 (1.1–6.1) | 81 (±6) | 47 (25–89) | 70 (±4) | 8.4 (6.1–11.5) | 126 (±3) | 33 (26–41) | 100 (±2) |
| Rotigotine | 0.05 (0.01–0.11) | 88 (±4) | 0.7 (0.3–1.4) | 79 (±4) | 0.5 (0.3–0.7) | 116 (±5) | ND | - |