Effect And Mechanism Of Ginsenoside Re Against Ang ?-induced Gap Junctional Remodeling In Beating Rat Atria

Background:(G-Re),a major ginsenoside in ginseng,possesses many beneficial and pharmacological effects on negative cardiac contractility,electromechanical alternans,antiarrhythmia,angiogenic regeneration,and cardiac electrophysiological function.However,the effect of G-Re on gap junctional remodeling is unclear.Therefore,this study aimed to investigate the effect of G-Re on angiotensin II(Ang II)-induced gap junctional remodeling in beating rat left atria.Methods:The isolated perfused beating rat atrial model was used and atrial myocardial remodeling was induced by Ang II.In vivo hemodynamic experiments was analyzed with a biological recorder.Changes in protein expression were analyzed by western blot.Results:1.G-Re against Ang ?-induced increase in the heart rate,MAP,LVESP,LVEDP,and+dp/dt max as well as-dp/dt min,and revealed a preventive role on Ang?-induced hyper hemodynamics by dose-dependent manner in rats.2.Atrial levels of p38 mitogen-activated protein kinase(MAPK)and nuclear factor kappa-B(NF-?B),activator protein 1(AP-1),were significantly increased by Ang II,as well as atrial collagen I and matrix metalloproteinase 2(MMP2)expression.Atrial connexin-40 and-43 expression was downregulated by Ang II.These Ang II-induced atrial effects were blocked by G-Re,and this inhibition was abolished by GW9662,an inhibitor of peroxisome proliferator-activated receptor y(PPARy),in isolated perfused beating rat atria.Conclusion:G-Re acts against Ang ?-induced gap junctional remodeling through activation of peroxisome proliferator-activated receptor y signaling in isolated perfused beating rat atria.