TABLE 6

Stimulation of [35S]GTPγS binding in stably mMOR-1B4-transfected CHO cells

Basal [35S]GTPγS binding was assessed in membranes from cells stably transfected with the indicated variants followed by the stimulation of [35S]GTPγS binding by the indicated drug at 25 μM. The stimulation was defined as the percentage increase over basal binding. Results are the means ± S.E.M. of at least three independent determinations.

Ligand Stimulation of [35S]GTPγS Binding
%
Morphine 16.7 ± 2.8
DAMGO 25.9 ± 2.6
Etorphine 27.6 ± 7.0
Fentanyl 31.7 ± 12.2
Etonitazene 34.6 ± 5.8
β-Endorphin 17.5 ± 2.6
Dynorphin A 38.5 ± 10.4