Table 1.
ED50 values of the analgesic effect of prototype opioid agonists in KOPr WT and KO mice
| ED50 | KOPr WT | KOPr KO |
|---|---|---|
| Fentanyl | 36.3 (26.3−50.1) μg/kg | 28.1 (22.3−35.4) μg/kg |
| SNC80 | 25.1 (11.0−57.3) mg/kg | 18.0 (8.0−40.3) mg/kg |
| U69593 | 0.68 (0.05−9.8) mg/kg | 34.2 (24.2−48.6)a mg/kg |
The analgesic effects of the MOPr agonist fentanyl and the DOPr agonist SNC80 did not differ between WT and KO mice.
U69593-evoked analgesia was decreased 50.5-fold in KO mice (P < 0.004).