Fig. 7. NH₄Cl and BFA, but not lactacystin, affect wild-type, but not mutant (Y286A) Cx43-dependent gap junctional communication. (A) SKHep1 cells stably expressing Cx43-WT or Cx43-Y286A were incubated for 3 hours either in new medium alone (control) or new medium supplemented with 10 µM lactacystin (Lactacystin), 10 mM NH₄Cl (NH₄Cl) or 2 µg/ml Brefeldin A (BFA). Intercellular communication was then assessed by microinjecting individual cells within a cluster, and recording three minutes later the number of lucifer yellow (LY)-labelled cells by fluorescent microscopy, the results of which are expressed as mean±s.e.m. The number of injections is displayed above the column and asterisks indicate differences at P<0.01 versus control as determined by the Student's t-test. (B) Distribution of junctional conductance values (open circles) evaluated in Cx43-WT and Cx43-Y286A cell pairs monitored under the dual patch-clamp technique. The mean±s.e.m. junctional conductance value calculated for each distribution is indicated by the black triangle and error bars. No significant difference (P=0.064) between the two cell clones was detected using the Student's t-test for unpaired data.