Figure 3.

Effect of 2-APB on electrical coupling of gap junction channels in NRK cells. (a) The central stream was switched between sucrose and sucrose with 2-APB (200 μM) repeatedly (indicated by arrows), showing that the drug reversibly blocks the channels. (b) A control experiment for the effect of DMSO used as the 2-APB vehicle, showing that the vehicle did not block the channels. The central stream was perfused alternately with sucrose + DMSO and sucrose. (c) and (d) Images of the cells before and after the experiment at the times indicated by the red arrows in (a), showing that the cells remain attached during the measurement. The scale bar represents 100 μm.