Fig. 4.
The addition of 500 μM Brilliant Black BN 1 min before NECA stimulation abolishes the antagonism mediated by 1 μM XAC at the adenosine A1 receptor. The time course of A1 receptor-mediated intracellular calcium mobilization in the absence (A and C) or presence (B and D) of 1 μM XAC after the addition of HBSS (A and B) or 500 μM Brilliant Black BN (C and D) at 15 s and NECA at 75 s (▿, absence; ▵, 10 pM; □, 100 pM; ○, 1 nM; ▾, 10 nM; ▴, 100 nM; ■, 1 μM; ●, 10 μM). Data represent the mean ± S.E.M. of three experiments conducted in triplicate, expressed as a percentage of basal fluorescence.