. 2023 Jun 13;26(7):107121. doi: 10.1016/j.isci.2023.107121

Table 2.

MOR, KOR, and DOR Gi/o-mediated cAMP inhibition data

Compound	MOR									KOR					DOR
Compound	EC50 (nM)	pEC50 ± SEM	Emax (% DAMGO)	Log (Emax/EC₅₀)	ΔLog (Emax/EC50)	MOR vs. KOR ΔΔLog (Emax/EC50)	MOR vs. KOR Selectivity	MOR vs. DOR ΔΔLog (Emax/EC50)	MOR vs. DOR Selectivity	EC50 (nM)	pEC50 ± SEM	Emax (% Sal A)	Log (Emax/EC₅₀)	ΔLog (Emax/EC₅₀)	EC50 (nM)	pEC50 ± SEM	Emax (% DADLE)	Log (Emax/EC₅₀)	ΔLog (Emax/EC₅₀)
Isotonitazene	0.033	10.48 ± 0.04	105.0 ± 1.1 ∗	10.49	1.85	4.96	>10,000	4.97	>10,000	335	6.48 ± 0.09	85.9 ± 4.1	6.41	−3.11	245	6.61 ± 0.07	89.9 ± 3.4	6.56	−3.13
Metonitazene	0.34	9.46 ± 0.06	104.9 ± 1.9	9.46	0.82	2.89	775	4.14	>10,000	25.9	7.59 ± 0.11	73.1 ± 3.3	7.45	−2.07	221	6.65 ± 0.16	51.9 ± 4.2	6.37	−3.32
N-desethyl isotonitazene	0.14	9.85 ± 0.06	115.7 ± 1.2 ∗	9.88	1.24	5.04	>10,000	4.22	>10,000	1060	5.98 ± 0.22	55.8 ± 8.3	5.72	−3.80	153	6.81 ± 0.18	77.1 ± 6.7	6.7	−2.99
Fentanyl	3.28	8.48 ± 0.06	104.1 ± 1.9	8.49	−0.16	1.74	55	3.27	1,850	19.7	7.70 ± 0.05	84.4 ± 3.6	7.63	−1.89	466	6.33 ± 0.08	86.2 ± 3.9	6.27	−3.42
Morphine	7.43	8.13 ± 0.06	86.1 ± 2.1 ∗	8.08	−0.56	2.33	215	2.48	302	207	6.68 ± 0.08	88.3 ± 1.7	6.63	−2.89	186	6.73 ± 0.06	82.9 ± 2.7	6.65	−3.04

All receptors are human receptors, and expressed in HEKT cells. All data represent mean and standard error of the mean (S.E.M) from at least three independent experiments performed in triplicate, and are represented as mean ± SEM. The pEC50 values for DAMGO, salvinorin A, and DADLE at their cognate receptors are 8.65 ± 0.04, 9.52 ± 0.04, 9.69 ± 0.06, respectively. E_max values at MOR marked with ∗ are statistically significantly different from that of DAMGO as determined by the extra sum-of-squares F test, with p < 0.0001.