| Objective: In this study, our aim was to explore the protective effects ofAstragaloside IV post-treatment after isolated perfused heart and myocardial cellsischemia reperfusion injury, and the role of Hif-1α signaling pathway and its downstreamgene iNOS pathway in the cardio protective of As IV post-treatment.Methods: Experiment One,2-MeOE2is the specificity inhibitor of Hif-1αsignalingpathway. We used Langendoff perfusion system to simulate isolated perfused heart andmyocardial cells ischemia reperfusion injury.48Sprague-Dawley rats were divided intofive groups, each group has8rats: Control group, I/R group, I/R+As IV group, I/R+AsIV+2-MeOE2group and I/R+2-MeOE2group. Open the rats cheat quickly and obtainedthe heart. The isolated heart was perfused for10min by the Langendoff perfusion system.After the heart beat stably. The control group continued perfusion for150min without notraetment. I/R group, I/R+As IV group and I/R+As IV+2-MeOE2group were ischemiafor90min and followed by60min reperfusion. Before ischemia, the I/R+As IV groupwas treated by As IV for10min, and I/R+As IV+2-MeOE2group was treat by AsIV+2-MeOE2for10min. HR,+dp/dt max, LVDP and CF were recorded respectively before ischemia and15,30,45,60min after reperfusion. After perfusion, TTC test wasused to detect the myocardial infarct size. LDH special kits were used to detect the level oflactic dehydrogenase in the coronary flow. The level of lactic dehydrogenase indicated thelevel of myocardial cells apoptosis rate. West-blot was used to detect the express of Hif-1α,iNOS, Bac-2and Caspase-3.Experiment Two, The cardiomyocytes were divided into five groups: Control group,SI/RI group, SI/RI+As IV group, SI/RI+As IV+2-MeOE2group and I/R+2-MeOE2group. After the cardiomyocytes be treated, MTT method was used to detect the survivalrate of cells; TUNEL and flow cytometry was used to detect the apoptotic rate of cells;The special kits were used to detect the level of superoxide dismutase andmalondialdehyde in the culture medium. West-blot was used to detect the express ofHif-1α, iNOS, Bac-2and Caspase-3.Results Experiment One, Compared with the control group, The HR,+dp/dt max andLVDP in the I/R group significantly decreased (P＜0.01), the myocardial infarct size andLDH dehydrogenase significantly increased (P＜0.01), the systolic and diastolic functionssignificantly reduced(P＜0.01), the level of myocardial cells apoptosis rate wassignificantly increased (P＜0.01) and in dose-dependent manner. Compared with the I/Rgroup, The HR,+dp/dt max and LVDP in the I/R+As IV group significantly increased (P＜0.01), the myocardial infarct size and LDH dehydrogenase significantly decreased (P＜0.01), the systolic and diastolic functions significantly improved (P＜0.01), the level ofmyocardial cells apoptosis rate was significantly decreased (P＜0.01). Compared with theI/R+As IV group, The HR,+dp/dt max and LVDP in the I/R+As IV+2-MeOE2groupsignificantly decreased (P＜0.01), the myocardial infarct size and LDH dehydrogenasesignificantly increased (P＜0.01), the systolic and diastolic functions significantlyreduced(P＜0.01), the level of myocardial cells apoptosis rate was significantly increased(P＜0.01). West-blot test showed, Compared with the control group, the Hif-1α, iNOs andBac-2in the I/R group were significantly decreased, Caspase-3was significantly increased(P＜0.01). Compared with the I/R group, the Hif-1α, iNOs and Bac-2in the I/R+As IV group were significantly increased, Caspase-3was significantly decreased (P＜0.01).Compared with the I/R+As IV group, the Hif-1α, iNOS and Bac-2in the I/R+AsIV+2-MeOE2group were significantly decreased, Caspase-3was significantlyincreased(P＜0.01). Compared with the I/R group, the parameters in the I/R+2-MeOE2group had no significantly difference (P＞0.05).Experiment Two, Compared with the control group, the survival of cells in SI/RIgroup decreased significantly,and the apoptotic rate of cells increased significantly(P＜0.01), as well as the malondialdehyde level in the culture medium increased significantlyand the superoxide level decreased significantly (P＜0.01). Compared with the SI/RIgroup, the survival of cells in SI/RI+As IV group increased significantly,and the apoptoticrate of cells decreased significantly(P＜0.01), as well as the malondialdehyde level in theculture medium decreased significantly and the superoxide level increased significantly(P＜0.01). Compared with the SI/RI+As IV group, the survival of cells in SI/RI+AsIV+2-MeOE2group decreased significantly,and the apoptotic rate of cells increasedsignificantly(P＜0.01), as well as the malondialdehyde level in the culture mediumincreased significantly and the superoxide level decreased significantly(P＜0.01).West-blot test showed, Compared with the control group, the Hif-1α, iNOS and Bac-2inthe SI/RI group were significantly decreased, Caspase-3was significantly increased(P＜0.01). Compared with the SI/RI group, the Hif-1α, iNOS and Bac-2in the SI/RI+As IVgroup were significantly increased, Caspase-3was significantly decreased (P＜0.01).Compared with the SI/RI+As IV group, the Hif-1α, iNOS and Bac-2in the SI/RI+AsIV+2-MeOE2group were significantly decreased, Caspase-3was significantlyincreased(P＜0.01). Compared with the I/R group, the parameters in the I/R+2-MeOE2group had no significantly difference(P＞0.05).Conclusion Astragaloside IV post-treatment has the protective effect after isolatedperfused heart and myocardial cells ischemia reperfusion injury, and Hif-1αsignalingpathway and its downstream gene iNOS pathway play an important role in the cardioprotective of As IV post-treatment. Astragaloside IV post-treatment can protect myocardial cells ischemia reperfusion injury via up-regulation Hif-1α signaling pathway. |
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