Table 3.
Effects of the presence of 1 μM of L-SPD on potency (EC50) and efficacy (Emax) of dopamine (DA) in stimulating D2 or D3 receptors to enhance [35S]GTPγS binding in CHO cells expressing the human D2 or D3 receptor. Basal [35S]GTPγS binding values were ~2000–3000 dpm. Each value represents mean ± S.E.M. (n = 3–5).
D2R | D3R | |||||
---|---|---|---|---|---|---|
Log[EC50(M)] | EC50 (μM) [Fold of DA] | Emax(% of basal) | Log[EC50(M)] | EC50 (μM) [Fold of DA] | Emax(% of basal) | |
DA | −6.08 ± 0.08 | 0.83 ± 0.14 [1] | 168.1 ± 1.6 | −7.30 ± 0.24 | 0.042 ± 0.019 [1] | 142.5 ± 2.9 |
DA + L-SPD 1 μM | −4.75 ± 0.19*** | 17.6 ± 7.9* [21] | 140.6 ± 3.8*** | −5.68 ± 0.30** | 2.08 ± 1.04* [50] | 139.9 ± 9.3 |
p < 0.001
p < 0.01
p < 0.05, relative to DA by t-tests.