Fig. 2. Gap junction coupling and Cx hemichannel activity in Calu-3 cells. (A) Representative micrographs of Calu-3 cells after GNOME-LP/DT experiments performed in absence or presence of the gap junction channel inhibitor carbenoxolone (CBX). The scale bar represents 200 µm. (B) The quantification of the experiments showed that CBX reduced the dye diffusion distance of LY from about 170 µm to about 110 µm. The results are shown as average ± SEM from twenty experiments with five cell culture passages. The data were statistically compared using student's t test (P<0.001 ***). (C) Time course of a dye uptake experiment showed that reduction of the external Ca²⁺ concentration accelerated the dye uptake as shown by the slope of the tangent to the dye uptake curve (red line). (D) Quantification of dye uptake experiments showing that various inhibitors of Cx hemichannels inhibited the dye uptake. The results are shown as average ± SEM of five experiments with three cell culture passages. The data were statistically compared using student's t test (P<0.01 **).