Receptor | Ligand | K (mean ± SEM) (nmol/L) | % Displacement |
---|
dre-µ | Met-ENK | 684 ± 15 | 73.97 ± 1.29 |
| Leu-ENK | 1,317 ± 166 | 58.51 ± 2.68 |
| β-END | 186 ± 25 | 88.45 ± 2.03 |
| MEGY | 204 ± 53 | 78.98 ± 3.73 |
| (d-Ala2)-MEGY | 744 ± 27 | 66.72 ± 0.81 |
| (d-Ala2, Val5)-MEGY | 3,645 ± 621 | 43.16 ± 3.39 |
| Morphine | 187 ± 94 | 100 |
| Naloxone | 10.65 ± 1.53 | 100 |
| | Ki (nmol/L) | Reference |
dre-δ1 | β-END | 36.6 | 29 |
| MEGY | 427 | 21 |
| Morphine | 22 | 29 |
dre-δ2 | Met-ENK | 45 | 30 |
| Leu-ENK | 175 |
| MEGY | 146 | 21 |
| Morphine | 1,400 | 30 |
rn-µa | Met-ENK | 1.80 | 5 |
| Leu-ENK | 6.19 |
| MERF | 0.37 |
| Morphine | 7.48 |
rn-δb | Met-ENK | 0.45 |
| Leu-ENK | 0.37 |
| MERF | 0.57 |
| Morphine | 302 |
tg-µc | Met-ENK | 70.7 | 32 |
| Leu-ENK | 117 |
| β-END | 55.9 |
tg-δc | Met-ENK | 24.9 |
| Leu-ENK | 198 |
| β-END | 284 |
- This table summarizes the results obtained in competition binding assays (Ki and % displacement) using (3H)-diprenorphine on membrane homogenates from HEK293 cells that stably express the µ opioid receptor from zebrafish. The results of other competition binding studies for the zebrafish δ opioid receptors dre-δ1 and dre-δ2, prototypical mammalian δ and µ receptors rn-oprm1 (rn, Rattus norvegicus (rat)) and rn-oprm1 and the amphibian µ and δ receptors tg-oprm1 and tg-oprd1 (tg, Taricha granulosa (newt)) have also been included for comparison.
- aIn this case, the radioligand used was the µ-selective peptidic analog (3H)-DAMGO and not (3H)-diprenorphine.
- bIn this case, the radioligand used was the δ-selective peptidic analog (3H)-DPDPE and not (3H)-diprenorphine.
- cIn this case, the radioligand used was the nonspecific antagonist (3H)-naloxone and not (3H)-diprenorphine.