FIGURE 2.

Activation of cAMP-dependent PKA by forskolin increases total cell TRPV1 multimerization. A, Western blot of TRPV1/MOP HEK cell protein from cells treated with 0.1% DMSO (Control), morphine (1 μm) and forskolin (FSK, 500 μm) in the absence or presence of morphine (1 μm, FSK+morphine). Non-transfected HEK cells were used as a control, with size markers in kDa shown on the right. Total cell lysates were prepared under non-reducing conditions and analyzed by SDS-PAGE on 4–20% precast gradient gels. Similar results were obtained in four independent experiments. B, optical density of TRPV1 multimer bands were obtained using MetaMorph (Molecular Devices), normalized to β-actin and expressed relative to control. Treatment with forskolin (FSK, black bar) significantly (^*, p < 0.05 compared with control by ANOVA) increased TRPV1 multimer density in total cell lysates.