Table 3.
Effects of R-6 analogs at human recombinant opioid receptors coupled with calcium signaling via chimeric G proteins
| Compound | µ-opioid receptors | δ-opioid receptors | ||
|---|---|---|---|---|
| pEC50 (CL95%)a | α ± SEM | pEC50 (CL95%) | α ± SEM | |
| Dermorphin | 8.26 ± 0.17 | 1.00 | Inactivea | |
| DPDPE | Inactive | 7.18 ± 0.26 | 1.00 | |
| R-6 | Inactive | 5.25 ± 0.45 | 0.28 + 0.04 | |
| 1 | 5.70 ± 0.23 | 0.22 ± 0.05 | Inactive | |
| 2 | Inactive | Inactive | ||
| 3 | Inactive | Inactive | ||
| 4 | Inactive | Inactive | ||
| 5 | 5.12 ± 0.33 | 0.11 ± 0.04 | 4.65 ± 0.78 | 0.39 ± 0.02 |
| 6 | Inactive | Inactive | ||
| 7 | Inactive | Inactive | ||
Dermorphin and DPDPE were used as reference agonists for calculating intrinsic activity at the µ- and δ-opioid receptors, respectively
aAgonist potency values (pEC50)
bEfficacy values (α); Inactive means that the compound was inactive as an agonist up to 1 µM. All values are expressed as the mean ± SEM of three independent experiments performed in triplicate