Figure 1.
Displacement of β-CIT binding to wild-type rat SERT by cocaine, ibogaine, imipramine, and fluoxetine in the presence or absence of Na+. Membranes from HeLa cells expressing rSERT were incubated with 0.15 nm [125I]β-CIT and the indicated concentrations of cocaine (0–20 μm), ibogaine (0–80 μm), imipramine (0–1.5 μm), and fluoxetine (0–1 μm) in either 150 mm NaCl (filled circles) or 150 mm NMDG-Cl (open circles). The concentration of β-CIT used (0.15 nm) was below the KD for binding in NMDG-Cl (2.6 nm), so as to minimize the effect of the lower β-CIT affinity in the absence of Na+. Representative results are presented as the percentage of [125I]β-CIT bound in the absence of the inhibitor. KI values calculated from multiple experiments and the corresponding statistical analyses are presented in Table 1.