Table 3 Signaling parameters for forskolin-stimulated cAMP accumulation in CHO-hKOR cells or using CHO-hKOR cell membranes.

U69,593 serves as the reference agonist. Data are presented as means ± SEM from n ≥ 4 independent experiments performed in duplicate to quadruplicate. P values were obtained by comparing the values of the KOR agonist treatment in CHO-hKOR cells to CHO-hKOR cell membranes using a Student’s t test.

Assay systemU69,5931.1Fold difference (EC50 1.1/EC50 U69)LogRΔLogR
hKOR (cell)*EC50 (nM)12 ± 2309 ± 6534 ± 98.02 ± 0.090
Emax (%)10094 ± 56.49 ± 0.12−1.64 ± 0.13
hKOR (membrane)EC50 (nM)35 ± 8155 ± 305 ± 0.67.54 ± 0.110
Emax (%)10098 ± 46.97 ± 0.14−0.57 ± 0.15

*Whole-cell forskolin-stimulated cAMP accumulation assay in CHO-hKOR cells was shown in Table 1 for comparison to the membrane-based forskolin-stimulated cAMP accumulation.

P < 0.01.

P < 0.05