EC50 values calculated for GIRK1/GIRK2 channel activation via hMOR, hKOR, or hDOR, coexpressed with RGS4 in Xenopusoocytes
| Ligand | EC50 | μ/δ Selectivity | μ/κ Selectivity | ||
|---|---|---|---|---|---|
| hMOR | hKOR | hDOR | |||
| nM | |||||
| p-Fluorofentanyl | 4.2 ± 1.0a | 157 ± 23a | 96 ± 15a | 23 ± 7a | 37.5 ± 10.7a |
| Sufentanyl | 8.6 ± 1.8b | 58.6 ± 6.8b | 185 ± 25b | 21.6 ± 5.4b | 6.8 ± 1.6a b |
| DAMGO | 24.5 ± 2.6 | >1000 | >1000 | N.D. | N.D. |
| Fentanyl | 28.8 ± 6.5a b 1-c | 291 ± 23a b 1-c | 790 ± 107a b | 27.4 ± 7.21-c | 10.1 ± 2.4b |
| Morphine | 206 ± 391-c | 810 ± 931-c | 678 ± 1421-c | 3.3 ± 0.9a b 1-c | 3.9 ± 0.91-c |
Statistical analysis of differences between groups was carried out with Student's t test (P < .05).
N.D., not determined.
↵1-c EC50 values containing the same letter designations are statistically different.