Table 2. Radioligand Binding Affinities for SYA0340-P1 and SYA0340-P2 at 5-HT1A and 5-HT7A Receptors.
| compound | 5-HT1AR [3H]8-OH-DPAT binding |
5-HT7AR [3H]5-HT binding |
||||
|---|---|---|---|---|---|---|
| Ki (nM) ± SEM | n | hill slope ± SEMb | Ki (nM) ± SEM | n | hill slope ± SEMb | |
| 5-HT | 2.24 ± 0.24 | 4 | –0.96 ± 0.06 | 0.46 ± 0.11 | 6 | –1.07 ± 0.09 |
| SYA0340 | 1.76 ± 0.51 | 10 | –0.66 ± 0.09 | 3.89 ± 0.79 | 6 | –0.59 ± 0.03 |
| SYA0340-P1 | 1.73 ± 0.55 | 4 | –0.58 ± 0.06 | 2.20 ± 0.33 | 6 | –0.59 ± 0.02 |
| SYA0340-P2 | 1.06 ± 0.32 | 3 | –0.53 ± 0.03 | 4.70 ± 1.10 | 6 | –0.59 ± 0.05 |
| lurasidone | NDa | NDa | NDa | 4.3 ± 1.3 | 7 | –0.76 ± 0.11 |
a
ND = not determined.
b
A Hill slope of less than −1.0 may suggest that the ligands ([3H]5-HT and (±)-, R- and S-enantiomers) interact with more than one (radioligand) binding site or possibly are involved in negative cooperative binding.