Fig. 1.
Recruitment of β-arrestin by the δOR agonist Delt II. Cells expressing (A) μβgalOR-δOR or (B) Flag μOR-δβgalOR (20,000 cells/well) were subjected to a β-arrestin recruitment assay with the δOR agonist Delt II (0–1 μM) as described in Materials and Methods. (C) Cells expressing μβgalOR-δOR were treated with Delt II (0–10 μM) in the absence or presence of μ-δ or CB1-AT1 mAb (1 μg/well), and β-arrestin recruitment was measured. (D) Cells expressing Flag μOR-δβgalOR were treated with DAMGO (0–1 μM) in the absence or presence of μ-δ, δ-CB1, μ-CB1, or CB1-AT1 mAb (1 μg/well), and β-arrestin recruitment was measured. Results are mean ± SE (n = 3–6). RLU, relative luminescence unit.