Figure 4.

Uptake and efflux analyses of T53A and T53D DATs. A and B, RDEV analysis of DA uptake and efflux. Superimposed representative traces WT DAT (black line), T53A DAT (red line), and T53D DAT (green line) show clearance of (A) 0.25 μm DA and (B) 1 μm DA, followed by application of 10 μm AMPH (arrow) to induce DA release. Kinetic values obtained from replicate experiments using 0.25–10 μm DA are presented in Table 1. C, WT- and T53A-LLCPK₁ cells loaded with [³H]DA were treated with vehicle or 10 μm AMPH for 5 min. Histogram shows amount of radioactivity (% of internal DA) collected in supernatants of each form (mean ± S.E. of 3 independent experiments), *, p < 0.05 versus vehicle for each form by Student's t test.