Fig. 2.

Monophasic competition data for antagonist binding to dopamine D₁ receptors. Competition was performed using variable concentrations of non-radiolabeled SCH 23390 and 2.7 nM [³H]SCH 23390 in lamb brain striatal membranes (0.5 mg protein/ml) using the protocol described in Ferrada et al., 2009. Data were fitted using equations derived from the two-state dimer receptor model (solid line) or derived from the assumption of one-affinity (monomeric) state (dashed line). The parameter values obtained by non-linear regression are indicated in Table 2.