Fig. 4.

Concentration-response curve for the slowing of the dissociation of [¹²⁵]I-AB-MECA by VUF5455. [¹²⁵I]I-AB-MECA (0.15 nM) was preassociated with human A₃ receptors in HEK293 cell membranes (25 μg protein) for 60 min at 37°C without additions (total binding) or in the presence of 30 μM NECA (nonspecific binding). At the end of the incubation period, 30 μM NECA was added simultaneously with vehicle or various concentrations of the tested compounds. The incubation was terminated after an additional 60 min. Control specific binding (B_control) at the end of the 60-min dissociation period was approximately 500 cpm, approximately 20% of the total binding. Data are mean values from three independent experiments performed in duplicate.