Fig. 6. (A,B) Immunofluorescence of Cx43 (red) and smooth muscle actin (green) in cultured myometrial cells from untreated (A) and tamoxifen-treated (B) Cx43fl/fl:SM-CreERT2 mice. Decrease in immunoreactive Cx43 in tamoxifen-treated Cx43fl/fl:SM-CreERT2 cultured SMCs is shown in contrast to untreated control cells. The colocalization of Cx43 and smooth muscle actin bundles is shown in yellow. (C) Immunoblot analyses of protein extracts (100 µg) of untreated and tamoxifen-treated Cx43fl/fl:SM-CreERT2 SMC cultures using antibodies to Cx26, Cx40, Cx45 or Cx43. Normalization to ß-actin levels revealed a reduction of Cx43 protein by 65±3%, levels of other connexin proteins investigated remained unchanged. Bar, 50 µm.