Fig. 3.
Time course of the dissociation of [3H]CGS21680 from A2A adenosine receptors. Rat striatal membranes (80 μg protein) were incubated with 15 nM [3H]CGS21680 at 25° for 90 min in 400 μL of 50 mM Tris·HCl, pH 7.7, containing 10 mM MgCl2. NECA (10 μM) was used to define nonspecific binding. Dissociation was started by the addition of 10 μM NECA in the presence and absence of the tested compounds. The data shown were from one experiment performed in duplicate. The k−1 values were calculated from three independent experiments and are listed in Table 1.