Figure 1.

Stimulation of Rho-123 efflux from the cells by QB102 is suppressed by the P-gp inhibitor verapamil. (a) QB102-mediated reduction of Rho-123 accumulation by Con A fibroblasts is suppressed by verapamil. Cells were incubated for 2 h with the indicated concentrations of Rho-123, QB102 (10 μM), and verapamil (1 μM) and cellular fluorescence was analyzed by flow cytometry. (b) Cells were loaded with Rho-123 by incubation in the presence of 1 μM of the dye and quickly washed with Rho-123-free medium, and the intensity of cellular fluorescence was determined 1.5 h later in the presence or absence of QB102 and verapamil by fluorescent microscopy. (c) The dynamics of Rho-123 fluorescence reduction were monitored by flow cytometry.