Table 4.
Compound | [RL] at 5% of forskolin response | [RL] at 10% of forskolin response | [RL] at 25% of forskolin response |
---|---|---|---|
NB397-1×MSH(4) | 13000 ± 1000 | 60000 ± 4900 | 420000 ± 34000 |
NB399-2×MSH(4) | 12000 ± 1300 | 45000 ± 4100 | 400000 ± 22000 |
NB341-3×MSH(4) | 14000 ± 1000 | 75000 ± 5400 | 450000 ± 33000 |
Receptor occupancy was calculated for the concentration of each ligand required to activate cAMP increase at 5%, 10% and 25% of the maximum observed with forskolin (10 μM) treatment using the following established equation: [RL] = Bmax ×x [L] / [L] + Kd. The Kd values used for this calculation were estimated from the competition binding assays (Figure 3). The numbers of receptors was assumed to be constant at 7.5 × 105 receptors per cell, as previously measured for this cell line32.