Molecular determinants for antagonist action are located in the TM3/4 region of TRPV1 IC50 values for antagonists at the pH 5 and capsaicin activation induced 45Ca2+ uptake in to CHO cells stably expressing TRPV1 are presented as mean ± S.D.
| Antagonist | pH 5 Activation | Capsaicin Activation | |||
|---|---|---|---|---|---|
| Rat | Rabbit | Rabbit-I550T | Rat | Rabbit-I550T | |
| nM | nM | ||||
| Group A | |||||
| AMG6880 | 24 ± 3 | >4000 | 167 ± 73 | 11 ± 6 | 3 ± 0.2 |
| AMG7472 | 2 ± 0.7 | >4000 | 7 ± 2 | 1 ± 0.6 | 3 ± 1 |
| BCTC | 0.6 ± 0.1 | >400 | 1.3 ± 0.2 | 0.4 ± 0.1 | 2 ± 1 |
| Group B | |||||
| AMG0610 | >4000 | >4000 | >4000 | 23 ± 3 | 24 ± 5 |
| Capsazepine | >4000 | >4000 | 421 ± 208 | 659 ± 155 | 477 ± 225 |
| SB-366791 | >4000 | >4000 | >4000 | 937 ± 207 | 720 ± 203 |
| P2X2/3 | |||||
| A-317491 | >4000 | >4000 | >4000 | >4000 | >4000 |