Competitor | 5-HT1DR | 5-HT1DR Gαi1β1γ2 | 5-HT1DR Gαoβ1γ2 | 5-HT1DR Gαqβ1γ2 | C6 Glioma |
---|---|---|---|---|---|
Agonists | |||||
5-HT | 8.4 ± 0.1 (3.8)2-a | 8.9 ± 0.2* (1.3) | 8.9 ± 0.1* (1.2) | 8.3 ± 0.1 (5.3) | 8.5 (2.9) |
Alniditan | 8.4 ± 0.5 (3.9) | 9.0 ± 0.3 (1.0) | 8.8 ± 0.6 (1.7) | 8.4 ± 0.8 (3.7) | 9.4 (0.4) |
Sumatriptan | 7.9 ± 0.5 (12.8) | 8.5 ± 0.2 (2.9) | 8.3 ± 0.2 (4.6) | 8.0 ± 0.3 (10.0) | 8.5 (3.5) |
Dihydroergotamine | 8.9 ± 0.4 (1.1) | 9.1 ± 0.4 (0.9) | 9.1 ± 0.5 (0.9) | 8.5 ± 0.2 (3.3) | 9.2 (0.7) |
Partial agonist | |||||
GR127935 | 8.6 ± 0.5 (2.6) | 8.5 ± 0.1 (3.2) | 9.0 ± 0.7 (1.0) | 8.4 ± 0.4 (4.0) | 8.6 (2.6) |
Antagonists | |||||
Ocaperidone | 10.4 ± 1.7 (0.04) | 7.0 ± 0.2* (102) | 7.0 ± 0.7* (101) | 9.9 ± 0.7 (0.3) | 8.8 (1.5) |
Methiothepin | >142-b | 6.5 ± 0.1 (344) | 6.8 ± 0.2 (170) | >142-b | 7.6 (28) |
Ketanserin | 7.2 ± 0.5 (66) | 5.8 ± 0.6* (1550) | 5.9 ± 0.3* (1370) | 7 ± 0.6 (96) | 7.5 (31) |
Radioligand binding was performed with 3 nM [3H]5-HT as described in the text. pIC50 values were derived from individual curves and used to calculate pKi values.Ki values (nM) were added between brackets to facilitate comparison with Table 1. Values for membrane material from a C6-glioma cell line stably expressing the 5-HT1DR were added for comparison and are from Leysen et al. (1996).
Statistical analysis was performed using Student's ttest: The asterisk (* P < 0.05) refers to the differences in Ki values with the noncoupled receptor.
↵2-a pKi values (−log M) (mean ± S.D.,n = 3) and Ki values (nM) (inside parens).
↵2-b >14 indicates that the lowest concentration of competitor tested (10−14 M) produced more than 50% inhibition of binding.