Fig. 7. Effect of βArr2 depletion on DAMGO- and morphine-induced OPRM1 desensitization in MEF cells.

Wild type, βArr2^−/− and βArr1/2^−/− MEF cells were infected with adenovirus containing OPRM1 and OPRM1 expressing level was monitored by receptor binding assay as described in experiment procedures. The abilities of 100nM DAMGO and morphine to induce the desensitization of OPRM1 in wild type MEF cells (■) βArr1/2^−/− MEF cells (○) and βArr2^−/− MEF cells (▲) was examined. Cells were pretreated with 100nM DAMGO or morphine, and agonist-induced desensitization was obtained as described in legend of Figure 2. Data summarize the average of n≥3 experiments in which the HEK293 cells were treated with 100nM DAMGO (panel A) and 100nM morphine (panel B) for various time to induce OPRM1 desensitization. *denotes p < 0.05 and ** denotes p< 0.01.