Effect of MOR antagonists on Wnt secretion. 293-MOR cells were transfected with myc-tagged Wnt2 cDNA. 24 hours after transfection, cells were treated with either (A) 10 μM CTAP (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2) or (B) 10 μM naloxone for one hour followed by an additional 23 hours of treatment with 1 μM morphine. Media was collected, proteins separated by SDS-PAGE, then transferred to a PVDF filter. Filters were probed with anti-myc antibodies and immunoreactive bands scanned by laser densitometry and quantitated using ImageJ software. In A and B, open bars represent untreated 293-MOR cells, black bars represent 293-MOR cells treated with morphine, and grey bars represent 293-MOR cells treated with either CTAP plus morphine or naloxone plus morphine. Data was analyzed using a two-sided Student's t-test (expressed as mean ± SEM; n= 5-6; *p < 0.05).