Table 1. Quantification and analysis of concentration-response curves of β-AR ligands.
| Ligand | Pharmacological property at β2-AR | Log Kd at β2-AR | Soft Agar Assay | SRB Assay | ||
|---|---|---|---|---|---|---|
| Log IC50 | Log IΔ2*PSD | Log IΔ2*PSD | % Efficacy/ Toxicity | |||
| Carvedilol | Biased agonist/ partial ERK agonist [43, 44] | -9.40 ± 0.08 [27] | -6.61 ± 0.06 | -7.24 ± 0.49 | -4.89 ± 0.09 | 94.65 ± 4.31 |
| Alprenolol | Biased agonist/ activates ERK [43] | -9.04 ± 0.07 [27] | -6.37 ± 0.06 | -7.04 ± 0.34 | -4.95 ± 0.06 | 93.78 ± 2.88 |
| Labetalol | Partial agonist for cAMP and full agonist for ERK [44, 45] | -8.03 ± 0.07 [27] | -6.30 ± 0.10 | -6.57 ± 0.44 | NT | 90.33 ± 8.48 |
| Nebivolol | Biased agonist/ activates ERK [46] | -7.91 ± 0.07 [47] | -5.96 ± 0.12 | -6.32 ± 0.46 | -4.65 ± 0.19 | 96.54 ± 7.24 |
| Pronethalol | Inverse agonist for cAMP [48] | -7.36 ± 0.07 [27] | -5.60 ± 0.04 | -6.48 ± 0.18 | -4.86 ± 0.23 | 100 |
| ICI 118,551 | Inverse agonist for cAMP that recruits ±-arr [29, 49] | -9.26 ±0.03 [27] | -5.35 ± 0.22 | -5.47 ± 0.50 | -3.59 ± 0.50 | Toxic |
| Timolol | Inverse agonist for cAMP [48] | -9.68 ± 0.02 [27] | -5.48 ± 0.06 | -6.25 ± 0.33 | -4.22 ± 0.34 | 100 |
| Atenolol | Inverse agonist for cAMP [50] | -5.99 ± 0.14 [27] | -5.04 ± 0.27 [19] | -5.04 ± 0.47 | NT | 47.88 ± 7.81 |
| Propranolol | Inverse agonist for cAMP that recruits ±-arr [29, 51] | -9.08 ± 0.06 [27] | -5.03 ± 0.15 | -5.26 ± 0.41 | -4.20 ± 0.11 | Toxic |
| Bucindolol | Partial agonist for cAMP and full agonist for ERK [44, 52] | -8.22 ± 0.1 [52] | -5.03 ± 0.07 | -5.72 ± 0.37 | -4.84 ± 0.10 | Toxic |
| Bupranolol | Antagonist, not specified | -9.85 ± 0.05 [27] | NC | -5.87 ± 0.31 | -4.80 ± 0.05 | Toxic |
| CGP 12177 | Partial agonist [53] | -9.39 ± 0.07 [27] | NC | -5.12 ± 0.34 | -4.46 ± 0.19 | Toxic |
| Carazolol | Inverse agonist for cAMP [54] | -8.96 ± 0.01 [55] | NC | -5.13 ± 0.31 | -5.00 ± 0.14 | Toxic |
| Acebutolol | Partial agonist [56] | -6.08 ± 0.07 [27] | NC | -4.31 ± 0.40 | -3.39 ± 0.70 | Toxic |
| Nadolol | Inverse agonist for cAMP [44, 57] | -8.60 ± 0.07 [27] | NC | -5.33 ± 0.31 | NT | ND |
| Metoprolol | Inverse agonist for cAMP [51] | -6.89 ± 0.09 [27] | NC | -4.61 ± 0.30 | -4.52 ± 0.20 | Toxic |
| Isoproterenol | Full equipotent agonist [44, 58] | -8.29 ± 0.02 [59] | NC | -4.61 ± 0.30 | -4.77 ± 0.16 | Toxic |
The pharmacological properties are described as in the references; not all ligands are equally characterized. β-arr is shorthand for β-arrestin. NC indicates that the IC50 is not calculated because the bottom of the curve, as calculated by GraphPad Prism 7.02, is less than two times the standard deviation of the vehicle control set (-14.26%). Calculation of Log IΔ2*PSD values is described in the Methods. NT indicates no toxicity at any concentration tested, and a 10-fold difference between IΔ2*PSD obtained from soft agar and SRB assays is considered effective at non-toxic concentrations. If non-toxic the efficacy is reported, but if toxic it is labeled “Toxic”; ND indicates that the value could not be mathematically determined.