Figure 4.

Effect of different ligands on the lateral mobility of TRPV1 in the plasma membrane of HMY-1/TRPV1 cells. The diffusion coefficients (A) and the mobile fractions (B) of MOR were obtained from FRAP measurements. The cells plated in a glass bottom chamber were treated with capsaicin (Caps, 0.5 µM) or endomorphin-2 (End-2, 1 µM) for 5 min before measurements. In some cases, the cells were incubated in the presence of the TRPV antagonist capsazepine (Cpz) or the MOR antagonist naloxone (both 10 µM) for 10 min prior to addition of the agonists. FRAP experiments were performed on the bottom cell membrane using a Zeiss LSM 880 confocal microscope. The data were collected from three independent experiments, at least 50 cells in each group. Results are expressed as means ± S.E.M. Asterisks denote significant differences between control (Ctrl) and different drug treatment groups (* p < 0.05, *** p < 0.001 compared to corresponding control).