Table 3.
Functional Activity of Test Drugs at 5-HT2 Receptors
| Drug | Human 5-HT2a Kact (nM ± SD) Vmax (percentage of 5-HT ± SD) | Human 5-HT2B Kact (nM ± SD) Vmax (percentage of 5-HT ± SD) | Human 5-HT2C Kact (nM ± SD) Vmax (percentage of 5-HT ± SD) |
|---|---|---|---|
| (±)-Fenfluramine | 4,131 ± 2,448 | ND | ND |
| 15 ± 4 | |||
| (+)-Fenfluramine | >10,000 | 379 ± 120 | 362 ± 109 |
| ND | 38 ± 14 | 80 ± 10 | |
| (−)-Fenfluramine | 5,279 ± 998 | 1,248 ± 430 | 360 ± 155 |
| 43 ± 7.2 | 47 ± 5 | 84 ± 15 | |
| (+)-Norfenfluramine | 630 ± 240 | 18.4 ± 9 | 13 ± 4 |
| 88 ± 9 | 73 ± 6 | 100 ± 11 | |
| (−)-Norfenfluramine | 1,565 ± 323 | 357 ± 180 | 18 ± 9 |
| 93 ± 9 | 71 ± 15 | 80 ± 17 | |
| Ergotamine | 16 ± 4 | 9.8 ± 3 | 5 ± 3 |
| 75 ± 3 | 56 ± 3 | 75 ± 15 | |
| Methysergide | 3.5 ± 1.7 | 150 ± 43 | 2.9 ± 1.5 |
| 24 ± 3 | 18 ± 4 | 33 ± 3.5 | |
| Methylergonovine | 1.3 ± 0.4 | 0.8 ± 0.5 | 2.5 ± 1.2 |
| 70 ± 7 | 40 ± 3 | 103 ± 7 | |
| Fluoxetine | ND | ND | Antagonist |
| Ki = 616 ± 172 | |||
| Norfluoxetine | ND | ND | Antagonist |
| Ki = 43 ± 17 | |||
| Trazodone | Antagonist | Antagonist | Antagonist |
| m-Chlorophenylpiperazine | 65 ± 17 | 64 ± 27 | 0.64 ± 0.3 |
| 55 ± 11 | 43 ± 14 | 79 ± 15 | |
| 5-HT | 66 ± 26 | 2.4 ± 1.5 | 0.6 ± 0.18 |
| 100 | 100 | 100 | |
| Phentermine | ND | ND | 1,394 ± 450 |
| 66 ± 10 |
Note. 5-HT = serotonin; ND = not determined. Values are mean ± SD for n = 3 experiments. Data taken from Rothman, Baumann et al. (2000).