Fig. 9.

Cx50R33E,E162R increases ethidium uptake in divalent cation-free solution. A Graph shows the increase in cellular fluorescence intensity in arbitrary units (F/F₀) after ethidium uptake when cells were incubated under physiological extracellular divalent cation concentrations (w/DC) for 20 min, followed by 20 min in Ca²⁺- and Mg²⁺-free Hanks’ balanced salt solution (DCF-HBSS), and, subsequently, in DCF-HBSS in the presence of 100 μM La³⁺ to block connexin hemichannels (La³⁺). B, C Bar graphs show the rate of ethidium uptake determined by calculating the slope of ethidium uptake in arbitrary units/minute (a.u./min) from the data presented in A under physiological conditions (B) or in divalent cation-free solution (C). Data are presented as mean ± S.E.M. (n = 3). ***p < 0.001 indicates significant differences vs. HeLa-Cx50 cells