Exploring pharmacological activities and signaling of morphinans substituted in position 6 as potent agonists interacting with the μ opioid receptor

Table 2 Agonist activities at the MOP receptor

	[ ³⁵S]GTPγS functional assay ^a		Calcium mobilization assay ^b
	EC ₅₀(nM)	E _max(%) ^c	EC ₅₀(nM)	E _max(%) ^c
Oxycodone	500 ± 128	92 ± 9	1,176 ± 347	38 ± 3
14-OMC	325 ± 94	137 ± 55	973 ± 204	72 ± 7
1	273 ± 24	98 ± 4	957 ± 233	57 ± 4
2	42.5 ± 14.9	97 ± 15	116 ± 9	69 ± 7
3	26.2 ± 1.7	85 ± 3	140 ± 21	61 ± 6
4	25.6 ± 9.5	107 ± 26	56.1 ± 11.3	59 ± 8
5	1.64 ± 0.19	133 ± 7	21.7 ± 5.5	70 ± 8
6	25.1 ± 3.6	121 ± 27	173 ± 21	84 ± 10
DAMGO	20.2 ± 5.6	100	42.7 ± 7.6	100

^aMembranes from CHO cells stably transfected with human MOP receptors were used. ^bCHO cells co-expressing Gα_qi5 protein and recombinant human MOP receptor were used. ^cE_max is expressed in percentage relative to maximal DAMGO induced stimulation in each assay (225 ± 32% and 217 ± 21% in [³⁵S]GTPγS functional and calcium mobilization assay, respectively, set as 100%). Values represent the mean ± SEM of at least three experiments each performed in duplicate or triplicate.

ISSN: 1744-8069