Inverse efficacies and potencies of different β2AR ligands assessed in membranes expressing the β2AR alone or in combination with Gαsβ1γ2
| Ligand | Einv | EC50(nM) | ||
|---|---|---|---|---|
| β2AR | β2AR/αsβ1γ2 | β2AR | β2AR/αsβ1γ2 | |
| n | (5–6) | (2) | (5–6) | (2) |
| Cyanopindolol | −0.37 (−0.26; −0.45) | −0.46 (−0.39; −0.53) | 301 (92.5; 783) | 373 (190; 556) |
| Propranolol | −0.69 (−0.53; −0.83) | −0.69 (−0.57; −0.81) | 5.3 (1.2; 24.1) | 5.2 (2.5; 8.0) |
| ICI 118551 | −1.00 | −1.00 | 6.9 (2.2; 21.5) | 10.4 (5.3; 15.5) |
E inv and EC50 values were determined as described under Materials and Methods. Data shown represent the means of n independent experiments performed in duplicate. The efficacies of cyanopindolol and propranolol were scaled with ICI 118551 efficacy set at −1.00. Numbers into brackets represent the minimum and maximum for each condition.