FIGURE 5.

Modulation of β-arrestin 2 recruitment by the A₁AR. (A) A₁AR-NanoBit^®-βarr2 HEK 293 cells were incubated with or without 1 µM of the positive A₁AR modulator VCP 171 and stimulated with 0.1 nM, 1 nM, or 100 nM NECA. In combination with 100 nM NECA, VCP 171 led to a significant increase in recruitment when compared to NECA treatment alone. Values are given as means ± SEM (n = 3 independent experiments performed in triplicate). **p < 0.01 value was significantly different (one-way analysis of variance, Dunnett’s post hoc). (B) A₁AR-NanoBit^®-βarr2 HEK 293 cells were incubated with 50 or 100 µM of the GRK2 inhibitor (βARK1) and stimulated with 100 nM or 1 µM NECA. Incubation with the inhibitor together with the higher NECA concentration led to a significant inhibition in recruitment when compared to cells stimulated with 1 µM NECA only. Values are given as means ± SEM (n = 3 independent experiments performed in triplicate). ***p < 0.001 value was significantly different (one-way analysis of variance, Dunnett’s post-hoc).