NBCe1 Na+-HCO3- cotransporter ablation causes reduced apoptosis following cardiac ischemia-reperfusion injury in vivo

The NBCe1 Na+-HCO3- cotransporter and NHE1 Na+/H+ exchanger both mediate Na+-loading and intracellular pH regulation in cardiomyocytes. Inhibition of NHE1 protects against ischemia-reperfusion (IR) injury, and evidence suggests that loss of NBCe1 activity could also be cardioprotective. We have developed a conditional NBCe1 knockout mouse model and have used it to determine the effects of NBCe1 ablation in cardiac muscle. These studies demonstrate that loss of NBCe1 does not impair cardiac performance. However, cardiomyocyte apoptosis following IR injury in vivo is much lower in hearts that lack NBCe1, thus indicating that loss of NBCe1 is cardioprotective.