Objective:To observe the effects of angiotensin Ⅱ(Ang Ⅱ) pefusion on transmural heterogeneity of Cx43 expression in the rabbit model with acute myocardial ischemia reperfusion(MIR),and investigate the role of rennin...Objective:To observe the effects of angiotensin Ⅱ(Ang Ⅱ) pefusion on transmural heterogeneity of Cx43 expression in the rabbit model with acute myocardial ischemia reperfusion(MIR),and investigate the role of rennin-angiotensin system in malignant ventricular arrhythmia induced by MIR.Methods:Twenty rabbits were randomly divided into MIR group(n=10) and Ang Ⅱ group(n=10).MIR model was produced with traditional ligation and opening of the anterior descending coronary artery in all animal.The hearts in vitro in the MIR group and the Ang Ⅱ group were perfused with simply improved Tyrode's solution and containing Ang Ⅱ Tyrode's solution respectively.90%monophasic action potential repolarization duration,transmural dispersion of repolarization.Cx43 protein(Cx43-pro) and mRNA(Cx43-Cq) expression in subepicardial,midmyocardial and subendocardial myocardium were measured in both groups.The greatest differences of Cx43-pro and Cx43-Cq among three myocardial layers were calculated and shown with △Cx43-pro and △Cx43-Cq respectively.Results:After Ang Ⅱ perfusion,90%monophasic action potential repolarization duration among three myocardial layer were significantly prolonged(P < 0.05 and P < 0.01),and transmural dispersion of repolarization also significantly increased compared with the MIR group(P < 0.05).Compare with the MIR group,three myocardial Cx43-pro and Cx43-Cq expression in the Ang Ⅱ group were significantly decreased(P < 0.05 and P < 0.01).but△Cx43-pro and △Cx43-Cq were significant increased.Conclusions:Renin-angiotensin system increases transmural heterogeneity of Cx43 expression in the rabbit model with MIR by Ang Ⅱ,and enlarge transmural dispersion of repolarization among three myocardial layers of left ventricular which induces malignant ventricular arrhythmia.展开更多
OBJECTⅣE This study aimed to investigate the role and mechanism of Astragaloside Ⅳ(AS-Ⅳ) in rats with myocardial infarction.METHODS The myocardial infarction model was established by ligation of the left anterior d...OBJECTⅣE This study aimed to investigate the role and mechanism of Astragaloside Ⅳ(AS-Ⅳ) in rats with myocardial infarction.METHODS The myocardial infarction model was established by ligation of the left anterior descending artery.The rats were randomly divided into sham,DMSO,model group,AS-Ⅳ and CID755673 groups.The rats were sacrificed 4 weeks later,and segmental heart samples were used for hematoxylin and eosin staining and masson staining.The expression of PKD1,HDAC5 and VEGF were analyzed using immunohistochemistry,reverse transcription poly.merase chain reaction and western blot.RESULTS Compared with the sham operation and DMSO groups,morphology of myocardium in model group was disordered,accompanied with necrotic myocar.dial cells and obvious collagen tissues.After treatment with AS-Ⅳ,the morphology of myocardium was obviously improved,and the number of new blood vessels increased significantly.However,after treatment with CID755673,the myocardial tissue of rats became disordered again,the necrotic cells increased,and some vessels closed.The expression levels of PKD1,HDAC5 and VEGF mRNA and protein in myocardial tissue of model group were significantly lower than the other four groups(P<0.05),whereas these levels in the AS-Ⅳ group were significantly higher than those in the other four groups(P<0.01).Additionally,the CID755673 group had significantly higher levels of PKD1,HDAC5 and VEGF mRNA and protein than the sham group,DMSO group and model group(P<0.05).CONCLUSION AS-Ⅳ may partly promote the angiogenesis of myocardial tissue in rats with myocardial infarction via the PKD1-HDAC5-VEGF pathway.展开更多
基金supported by National Natural Science Foundation of China(NO.81160024)Natural Science Foundation of Hainan Province(NO.814371)
文摘Objective:To observe the effects of angiotensin Ⅱ(Ang Ⅱ) pefusion on transmural heterogeneity of Cx43 expression in the rabbit model with acute myocardial ischemia reperfusion(MIR),and investigate the role of rennin-angiotensin system in malignant ventricular arrhythmia induced by MIR.Methods:Twenty rabbits were randomly divided into MIR group(n=10) and Ang Ⅱ group(n=10).MIR model was produced with traditional ligation and opening of the anterior descending coronary artery in all animal.The hearts in vitro in the MIR group and the Ang Ⅱ group were perfused with simply improved Tyrode's solution and containing Ang Ⅱ Tyrode's solution respectively.90%monophasic action potential repolarization duration,transmural dispersion of repolarization.Cx43 protein(Cx43-pro) and mRNA(Cx43-Cq) expression in subepicardial,midmyocardial and subendocardial myocardium were measured in both groups.The greatest differences of Cx43-pro and Cx43-Cq among three myocardial layers were calculated and shown with △Cx43-pro and △Cx43-Cq respectively.Results:After Ang Ⅱ perfusion,90%monophasic action potential repolarization duration among three myocardial layer were significantly prolonged(P < 0.05 and P < 0.01),and transmural dispersion of repolarization also significantly increased compared with the MIR group(P < 0.05).Compare with the MIR group,three myocardial Cx43-pro and Cx43-Cq expression in the Ang Ⅱ group were significantly decreased(P < 0.05 and P < 0.01).but△Cx43-pro and △Cx43-Cq were significant increased.Conclusions:Renin-angiotensin system increases transmural heterogeneity of Cx43 expression in the rabbit model with MIR by Ang Ⅱ,and enlarge transmural dispersion of repolarization among three myocardial layers of left ventricular which induces malignant ventricular arrhythmia.
基金supported by National Natural Science Foundation of China(8147343881202791)+2 种基金 Science and Technology Project of Henan Province(162102310011) Key Research Projects of Henan Colleges and Universities(18B360011) Funding Scheme for the Young Backbone Teache
文摘OBJECTⅣE This study aimed to investigate the role and mechanism of Astragaloside Ⅳ(AS-Ⅳ) in rats with myocardial infarction.METHODS The myocardial infarction model was established by ligation of the left anterior descending artery.The rats were randomly divided into sham,DMSO,model group,AS-Ⅳ and CID755673 groups.The rats were sacrificed 4 weeks later,and segmental heart samples were used for hematoxylin and eosin staining and masson staining.The expression of PKD1,HDAC5 and VEGF were analyzed using immunohistochemistry,reverse transcription poly.merase chain reaction and western blot.RESULTS Compared with the sham operation and DMSO groups,morphology of myocardium in model group was disordered,accompanied with necrotic myocar.dial cells and obvious collagen tissues.After treatment with AS-Ⅳ,the morphology of myocardium was obviously improved,and the number of new blood vessels increased significantly.However,after treatment with CID755673,the myocardial tissue of rats became disordered again,the necrotic cells increased,and some vessels closed.The expression levels of PKD1,HDAC5 and VEGF mRNA and protein in myocardial tissue of model group were significantly lower than the other four groups(P<0.05),whereas these levels in the AS-Ⅳ group were significantly higher than those in the other four groups(P<0.01).Additionally,the CID755673 group had significantly higher levels of PKD1,HDAC5 and VEGF mRNA and protein than the sham group,DMSO group and model group(P<0.05).CONCLUSION AS-Ⅳ may partly promote the angiogenesis of myocardial tissue in rats with myocardial infarction via the PKD1-HDAC5-VEGF pathway.
