Sodium Pump Mediates Endoplasmic Reticulum Stress In Myocardial Ischemia-reperfusion Injury

Objective:To study the relationship between sodium pump and myocardial ischemia reperfusion(ischemia reperfusion,IR)injury at the cellular level,and to study the correlation of endoplasmic reticulum stress and myocardial ischemia-reperfusion injury.Finally to determine whether sodium pump mediates endoplasmic reticulum stress in myocardial ischemia-reperfusion injury.Methods:Constructed hypoxia reoxygenation model after the original generation culture of the myocardial cell.Each group was given different intervention during the hypoxia reoxygenation process.Experiments were divided four groups:(1)control group,(2),hypoxia reoxygenation group(I/R),(3),hypoxia reoxygenation + Ouabain group(Ouabain-I/R),(4),hypoxia reoxygenation + Digoxin antiserum group(Anti Digoxin-I/R).After completion of hypoxia reoxygenation,apoptosis index was detected by flow cytometry;and the expression levels of GRP78,endoplasmic reticulum stress signaling molecules and Bax,apoptosis protein were aslo detected by western blot.Results: 1,The apoptosis index: compared with control group,the I/R group cell activity decreased and the apoptosis rate increased(P < 0.05).Compared with I/R group,the apoptosis rate of Ouabain-I/R group increased(P < 0.05),the apoptosis rate of Anti Digoxin-I/R group decreased(P < 0.05).2,Western blot: Compared with control group,the expression of Bax,GRP78 protein were increased in the I/R group(P <0.05).Compared with I/R group,the expression of Bax,GRP78 protein was increased in Ouabain-I/R group(P < 0.05),but decreased in Anti Digoxin-I/R group(P < 0.05).Conclusion: 1,Hypoxia reoxygenation aggravates myocardial cell apoptosis.2,Inhibition of sodium pump activity aggravates endoplasmic reticulum stress,and increases myocardial cell apoptosis.While activating the sodium pump activity could alleviate endoplasmic reticulum stress,and reduce myocardial cell apoptosis.3,Sodium pump may mediates endoplasmic reticulumstress in myocardial ischemia-reperfusion injury.