TABLE 2

[³⁵S]GTPγS binding in Tet-Off cells expressing mMOR-1/mMOR-1G

[³⁵S]GTPγS binding was performed using membranes from −Doxy and +Doxy cells with six conc. of indicated drugs (0–10 µM), as described in Materials and Methods. EC₅₀ and % stimulation values over basal level (% stim) were calculated by nonlinear regression analysis (Prism 7). So, the basal level is, as always, 0%. Results are the mean ± S.D. of three independent experiments. Significant differences between −Doxy and +Doxy groups were analyzed by two-tailed Student’s t test.

	mMOR-1/mMOR-1G
	+Doxy (100 ng/ml) No mMOR-1G		−Doxy (0 ng/ml) With mMOR-1G
	EC₅₀ (µM)	% stim	EC₅₀ (µM)	% stim	95% CI of % stim^a
Morphine	0.2 ± 0.1	34 ± 5	0.3 ± 0.0	109 ± 24^*	−145 to −5.5
Increase of % stim: ↑ 321%
DAMGO	0.6 ± 0.1	63 ± 1	0.2 ± 0.0**	139 ± 19**	−124 to −27
Increase of % stim: ↑ 221%
M6G	0.7 ± 0.5	43 ± 18	0.2 ± 0.0	91 ± 22^*	−87 to −9.0
Increase of % stim: ↑ 212%
Β-endorphin	0.8 ± 0.5	75 ± 16	0.9 ± 0.2	139 ± 71	−224 to 97
Increase of % stim: ↑ 183%

^a CI, Confidence Interval.
↵* P < 0.05; **P < 0.01.