Overexpression of Cx43 increases gap junction activity. Cells were treated with: no transfection (control), transfection of Empty Vector (control), transfection of Cx43 for 24 hours. Level of Cx43 and its isoforms were examined by western blot analysis. GAPDH was used as a loading control. A) Levels of Cx43 were examined using anti-connexin43 (F-7) antibody specific for amino acids 357–381 at the C-terminus domain. B) Graphical presentation of three independent experiments showing pixel intensities of total Cx43 normalized to Empty Vector (control). C) Scrape Load/Dye transfer assay (SL/DT) was performed after no transfection and the transfection of overexpression of Cx43. Lucifer yellow dyes in cells indicate in white. Red line indicates the point of entry for Lucifer yellow. D) Graphical presentation shows the ratio of Cx43 isoforms P0, P1 and P2 from panel A. Data were obtained in three independent experiments and are represented as the mean ± SD. *P value is <0.05 compared to control. IB = Immunoblot against Cx43.