Figure 4.

Competitive ligands significantly enhance the dissociation of 30 nM ABA-X-BY630 from the A₃-AR. A–C) ABA-X-BY630 (30 nM) dissociation kinetics from CHO-A₃ cells in the absence (●) or presence of XAC (A; ○ 10 nM, ▾ 100 nM, ▿ 1 μM, ▴ 10 μM); NECA (B; ○ 100 nM, ▾ 1 μM, ▿ 10 μM, ▴ 100 μM); or adenosine (C; ▾ 1 μM, ▿ 10 μM, ▴ 100 μM). D–F) ABA-X-BY630 (30 nM) dissociation kinetics from CHO-A₁ cells in the absence (●) or presence (○) of XAC (D; 10 μM), NECA (E; 100 μM) or adenosine (F; 100 μM). Rate of perfusion was maintained at >12 complete fluid exchanges/min. Specific binding data was normalized as a percentage of fluorescent intensity at t =0 and globally analyzed according to a monophasic exponential decay. Data points are expressed as means ± se from 3–11 separate experiments; each replicate represents the average of 10 cells.