TABLE 1.
Potency and maximal effects of the compounds tested for downstream effectors of the D2R
Data are an average of at least three individual experiments conducted in duplicate. For EC50 values, the 95% confidence interval is shown in parentheses. Maximal effects are shown as a percentage of dopamine’s maximal response, and S.E.M. is shown in parentheses. Potency ratios of β-arrestin recruitment/Gαi/o activation were also included.
| Compound |
β-Arrestin 2 Recruitment |
Gαi/o Activation |
Gβγ Activation |
Potency (EC50) Ratio |
|||
|---|---|---|---|---|---|---|---|
| EC50 | Max Effect (% Dopamine) | EC50 | Max Effect (% Dopamine) | EC50 | Max Effect (% Dopamine) | β-Arrestin/Gαi/o | |
| nM | nM | nM | |||||
| Dopamine | 124 (100–153) | 100 (± 2) | 1.2 (0.7–2.1) | 100 (± 3) | 171 (72–407) | 100 (± 8) | 103 |
| Quinpirole | 64 (59–70) | 96 (± 1) | 1.2 (0.9–1.6) | 100 (± 2) | 145 (89–236) | 103 (± 4) | 53 |
| Lisuride | 0.4 (0.3–0.6) | 66 (± 2) | 0.07 (0.04–0.14) | 106 (± 5) | 2.2 (0.4–12.0) | 30 (± 6) | 9 |
| Bromocriptine | 2.9 (1.9–4.4) | 101 (± 4) | 1.9 (0.9–4.3) | 104 (± 3) | 0.5 (0.1–2.1) | 34 (± 5) | 2 |
| Aripiprazole | 3.6 (2.5–5.2) | 19 (± 1) | 1.3 (0.5–3.1) | 65 (± 4) | ND | −19 (± 5) | 3 |
| Rotigotine | 0.2 (0.1–0.3) | 111 (± 4) | 0.02 (0.007–0.03) | 95 (± 3) | 1.5 (0.3–6.9) | 54 (± 9) | 10 |
| (+)-3-PPP | 925 (809–1058) | 92 (± 1) | 8.6 (4.9–15.1) | 108 (± 4) | 518 (136–1973) | 57 (± 9) | 108 |
| RNPA | 1.9 (1.5–2.5) | 101 (± 2) | 13 (3–57) | 95 (± 13) | 360 (210–619) | 110 (± 11) | 0.1 |
| Pramipexole | 12 (10–15) | 94 (± 2) | 0.2 (0.1–0.3) | 108 (± 3) | 20 (9–46) | 86 (± 5) | 60 |
| Ropinirole | 49 (37–63) | 92 (± 2) | 0.5 (0.3–0.8) | 111 (± 4) | 100 (34–290) | 56 (± 6) | 98 |
| Pergolide | 7.2 (5.9–8.9) | 90 (± 2) | 0.04 (0.02–0.07) | 101 (± 4) | 2.3 (0.6–9.5) | 38 (± 7) | 180 |
ND, not determined.