Table 5.
Efficacy and potency of F15599 and comparators for stimulation of [35S]-GTPγS binding to membranes prepared from various brain regions
| Tissue/cell line |
F15599 |
F13714 |
(+)8-OH-DPAT |
5-HT |
||||
|---|---|---|---|---|---|---|---|---|
| Emax (%) | pEC50 | Emax (%) | pEC50 | Emax (%) | pEC50 | Emax (%) | pEC50 | |
| Prefrontal cortex | 54 ± 3 | 7.20 ± 0.04 | 54 ± 6 | 9.19 ± 0.08 | 65 ± 2 | 7.62 ± 0.14 | 92 ± 5 | 7.25 ± 0.05 |
| Entorhinal cortex | 63 ± 7 | 7.00 ± 0.14 | 65 ± 12 | 9.14 ± 0.01 | 75 ± 6 | 7.41 ± 0.05 | 101 ± 7 | 7.07 ± 0.08 |
| Hippocampus | 78 ± 2 | 6.85 ± 0.03 | 77 ± 2 | 9.02 ± 0.04 | 77 ± 3 | 7.59 ± 0.04 | 101 ± 1 | 6.99 ± 0.03 |
| Dorsal raphe | 68 ± 8 | 6.42 ± 0.12 | 64 ± 4 | 8.73 ± 0.08 | n.d. | n.d. | ||
| Median raphe | 57 ± 2 | 6.62 ± 0.06 | 57 ± 2 | 8.82 ± 0.07 | n.d. | n.d. | ||
Efficacy (Emax) values are expressed as % of the stimulation induced by saturating concentrations (10 µmol·L−1) of 5-HT. Slope values of the [35S]-GTPγS binding isotherms did not significantly differ from unity except in: (i) dorsal raphe F15599 0.62 ± 0.07, F13714 0.76 ± 0.03; (ii) median raphe F13714 0.69 ± 0.03; and (iii) prefrontal cortex (+)8-OH-DPAT 0.59 ± 0.06.
n.d., not determined.