Radioligand binding, functional potency, and efficacy of lorcaserin for human and rat 5-HT2 receptors
Values listed in this table are the mean ± S.E.M. of the indicated number of independent IC50 (radioligand binding assay) and EC50 (IP accumulation assay) determinations (in parentheses). Triplicate determinations were performed at each of eight different test compound concentrations. Ki values from radioligand competition studies with [125I]DOI were calculated from IC50 values as described under Materials and Methods. Efficacy (the % 5-HT response column) was determined by comparison with 10 μ M 5-HT, which was assigned a value of 100%.
Receptor | Affinity Ki | Potency EC50 | Efficacy (% 5-HT Response) | |
|---|---|---|---|---|
| nM | ||||
| Human 5-HT2C | 15 ± 1 (28) | 9 ± 0.5 (40) | 100 | |
| Human 5-HT2A | 112 ± 7 (25) | 168 ± 11 (34) | 75 | |
| Human 5HT2B | 174 ± 32 (18) | 943 ± 90 (35) | 100 | |
| Rat 5-HT2C | 29 ± 7 (7) | 193 ± 12 (4) | 100 | |
| Rat 5-HT2A | 159 ± 27 (14) | 676 ± 129 (3) | 100 | |
| Rat 5-HT2B | 190 ± 5 (3) | 272 ± 87 (4) | 100 | |