Fig. 4.

Competitive binding of 19 with a non-selective antagonist, XAC, and an A₃AR-selective agonist, IB-MECA, in HEK293 cells expressing hA₃AR determined using FCM. Fluorescence intensity was measured using a Beckman Coulter CytoFLEX B4-RO-VO System with a 638-nm laser and a 780/60 bandpass filter. A K_i of 171 ± 29 nM (N = 2) was calculated for XAC and 71 ± 17 nM (N = 2) for IB-MECA based on a K_d of 11.8 nM for 19 at hA_2AAR