Table 1. Δ6-Gαqi4myr-mediated Ca2+ release of HEK-293 cells stably expressing opioid receptors
Ca2+ release 6′-GNTI U69,593 DPDPE DAMGO
EC50, nM
    KOP 224.4 ± 14.2 0.83 ± 0.07 >1,000 >1,000
    DOP >1,000 >1,000 22.1 ± 1.3 >1,000
    MOP >1,000 >1,000 >1,000 6.5 ± 2.2
    KOP/DOP 39.8 ± 3.0 0.82 ± 2.5 53.1 ± 2.2 >1,000
    KOP/MOP 112.5 ± 3.1 0.34 ± 3.2 >1,000 20.9 ± 1.8
    DOP/MOP >1,000 >1,000 43.2 ± 6.7 5.6 ± 2.6
E max, RLU
    KOP 367.9 ± 165.7 518.8 ± 299.8
    DOP 295.6 ± 65.4
    MOP 689.4 ± 314.0
    KOP/DOP 404.3 ± 140.2 570.7 ± 156.6 441.2 ± 33.0
    KOP/MOP 272.2 ± 137.2 458.1 ± 206.8 536.2 ± 270.9
    DOP/MOP 604.8 ± 209.1 531.7 ± 210.9
  • Data are mean ± SEM (n = 3-5). RLU, relative luciferase units; DAMGO, [d-Ala2-MePhe4-Gly5-ol]; —, not applicable.