Stimulation of [35S]GTPγ S binding by agonist at h5-HT2C receptors
| Ligand | No Pertussis Toxin | With Pertussis Toxin | ||
|---|---|---|---|---|
| pEC50 | Emax | pEC50 | Emax | |
| % | % | |||
| 5-HT | 8.08 ± 0.08 | 100.0 ± 5.7 | 8.64 ± 0.081-213 | 46.0 ± 4.2 (100)1-a |
| Ro600175 | 7.80 ± 0.17 | 104.5 ± 5.3 | 8.52 ± 0.151-213 | 47.7 ± 2.5 (103)1-a |
| DOI | 7.72 ± 0.10 | 75.1 ± 6.41-150 | 8.05 ± 0.091-213 | 50.3 ± 3.6 (109)1-a |
| LSD | 8.06 ± 0.13 | 44.7 ± 4.91-150 | 8.00 ± 0.03 | 38.1 ± 2.3 (83)1-a |
| Lisuride | 7.47 ± 0.08 | 24.2 ± 2.81-150 | 7.76 ± 0.19 | 18.4 ± 3.21-150(40)1-a |
Agonist efficacies were determined by [35S]GTPγ S binding at membrane preparation from CHO–h5-HT2C cells treated or not treated with pertussis toxin. Agonist efficacies are expressed relative to that of 5-HT (1 μ M) determined in the absence of pertussis toxin and are means ± S.E.M. of at least three independent experiments.
↵1-213 pEC50 values were significantly different (P < 0.05, unpaired ttest) in the presence of pertussis toxin except for LSD and lisuride.
↵1-150 E max values differed significantly (P < 0.05, unpaired t test) versus 5-HT effect.
↵1-a Values in brackets are normalized versus 5-HT effect (100%) in the presence of PTX. Note that theseE max values closely resemble those for Gq/11 activation (see Table 2).