Fig. 7.

Brilliant Black BN (500 μM) significantly decreases the affinity of XAC, but not DPCPX or NECA, for the adenosine A₁ receptor. The inhibition of [³H]DPCPX (1 nM) specific binding by DPCPX (circles), NECA (triangles), or XAC (squares) in the absence (closed symbols) and presence (open symbols) of Brilliant Black BN (500 μM) to CHO A₁ cells at 37°C. Nonspecific binding was defined 1 nM [³H]DPCPX binding in the presence of 10 μM DPCPX. Data are expressed as the percentage of [³H]DPCPX-specific binding and represent the mean ± S.E.M. of four experiments conducted in triplicate.