Figure 3.

IPoC delayed the recovery of tissue resistivity and epicardial activation regardless of Cx43 expression in isolated mice hearts. (A) After 30 min of global ischemia (in grey), 6 cycles of 10 s reperfusion/10s global ischemia delayed tissue resistivity recovery in Cx43^fl/fl (Flox) and in Cx43^Cre-ER(T)/fl (Cre) mice treated with either oil (Flox-Oil 100%, and Cre-Oil 50% Cx43 expression) or 4-Hydroxytamoxifen (Tx) (Flox-Tx 100%, and Cre-Tx <5% Cx43 expression). The inset shows the values from the last min of ischemia to the 5th min of reperfusion. * p < 0.05 vs. each Control by repeated measures ANOVA. (B) IPoC delayed tissue resistivity recovery in mice in which the coding region of Cx43 is replaced by that of connexin 32 (Cx32). Only homozygous (Cx32-HOM) and wild-type (WT) animals were included. (C) IPoC induced a delay in epicardial activation and action potential shortening as can be seen in representative traces from the 4th min of reperfusion. (D) Cre-Tx showed a delay before ischemia but the response to IPoC was no different from those with full content of Cx43 (Flox-Oil). * p < 0.05 vs. Flox and # p < 0.05 vs. Control by repeated measures ANOVA.