Integrated network pharmacology and metabolomics to explore the mechanisms of Shenzao dripping pill against chronic myocardial ischemia

Background:Shenzao dripping pill(SZDP)is empirically prescribed for treating cardiac diseases.Nevertheless,there is a lack of comprehensive knowledge regarding the underlying mechanisms contributing to its therapeutic effects.The objective of this study is to investigate the underlying mechanism of SZDP against chronic myocardial ischemia(CMI)in a rat model.Methods:In this study,we utilized electrocardiographic and echocardiographic detection along with pathological tissue analysis to evaluate the efficacy of SZDP.The integration of network pharmacology and metabolomics was conducted to investigate the mechanisms.Molecular docking and molecular dynamics simulations were used to validate the binding energy between the compounds of SZDP and the associated targets.Results:The results showed that SZDP was able to improve T wave voltage,reverse CMI abnormalities in ejection fraction and fractional shortening,and restore histopathological heart damage.Metabolomics results indicated that disturbances of metabolic profile in CMI rats were partly corrected after SZDP administration,mainly affecting purine metabolism.13-Docosenamide may be the potential metabolic biomarker of the therapeutic application of SZDP for CMI.Integrating network pharmacology and metabolomics,thiopurine S-methyltransferase(TPMT),xanthine dehydrogenase/oxidase(XDH),bifunctional purine biosynthesis protein ATIC(ATIC),and cytochrome p4501A1(CYP1A1)were identified as possible targets of SZDP to exert therapeutic effects by enhancing the metabolic levels of L-Tryptophan,Deoxyribose 1-phosphate and Phosphoribosyl formamidocarboxamide.Conclusion:SZDP has a therapeutic effect on CMI by regulating metabolite levels,acting on the targets of TMPT,XDH,ATIC,and CYP1A1,and reducing cardiomyocyte injury and myocardial fibrosis.

Buxu Tongyu Granule Alleviates Myocardial Ischemia by Activating Vascular Smooth Muscle Cell Soluble Guanylate Cyclase to Inhibit Abnormal Vasomotion

Myocardial ischemia is a serious threat to human health,and vascular dysfunction is its main cause.Buxu Tongyu(BXTY)Granule is an effective traditional Chinese medicine(TCM)for treating myocardial ischemia.However,the underlying mechanism of BXTY is still unclear.In this study,we demonstrate that BXTY ameliorates myocardial ischemia by activating the soluble guanylate cyclase(sGC)-30,50-cyclic guanosine monophosphate(cGMP)-protein kinase G(PKG)signaling pathway in vascular smooth muscle cells(VSMCs)to dilate the arteries.BXTY was given by gavage for ten consecutive days before establishing an animal model of acute myocardial ischemia in mice via the intraperitoneal injection of pituitrin.The results showed that BXTY alleviated the symptoms of myocardial ischemia induced by pituitrin in mice,including electrocardiogram abnormalities and changes in plasma enzymes.In addition,BXTY dilated pre-constricted blood vessels and inhibited the vasoconstriction of the superior mesenteric artery in a dose-dependent but endothelial-independent manner.These effects were eliminated by preincubating vascular rings with the sGC inhibitors NS 2028 or ODQ,or with the PKG inhibitor KT 5823.Moreover,BXTY increased the protein expression of sGC-b1 and the intracellular second messenger cGMP level in mouse aortic vascular smooth muscle cells(MOVAs).NS 2028 or ODQ reversed these effects of BXTY.The expression level of the cGMP downstream effector protein PKG-1 increased after treating MOVAs with BXTY.NS 2028,ODQ,or KT 5823 also reversed this effect of BXTY.In conclusion,BXTY can improve the symptoms of acute myocardial ischemia in mice,and activating the sGC-cGMP-PKG pathway in VSMCs to induce vasodilation is its key pharmacodynamic mechanism.

Inhibition of SLC26A4 regulated by electroacupuncture suppresses the progression of myocardial ischemia-reperfusion injury

Introduction:Myocardial ischemia-reperfusion(IR)injury has received widespread attention due to its damaging effects.Electroacupuncture(EA)pretreatment has preventive effects on myocardial IR injury.SLC26A4 is a Na+independent anion reverse transporter and has not been reported in myocardial IR injury.Objectives:Tofind potential genes that may be regulated by EA and explore the role of this gene in myocardial IR injury.Methods:RNA sequencing and bioinformatics analysis were performed to obtain the differentially expressed genes in the myocardial tissue of IR rats with EA pretreatment.Myocardial infarction size was detected by TTC staining.Serum CK,creatinine kinase-myocardial band,Cardiac troponin I,and lactate dehydrogenase levels were determined by ELISA.The effect of SLC26A4 on cardiomyocyte apoptosis was explored by TUNEL staining and western blotting.The effects of SLC26A4 on inflammation were determined by HE staining,ELISA,and real-time PCR.The effect of SLC26A4 on the NF-κB pathway was determined by western blotting.Results:SLC26A4 was up-regulated in IR rats but downregulated in IR rats with EA pretreatment.Compared with IR rats,those with SLC26A4 knockdown exhibited improved cardiac function according to decreased myocardial infarction size,reduced serum LDH/CK/CK-MB/cTnI levels,and elevated left ventricular ejection fraction and fractional shortening.SLC26A4 silencing inhibited myocardial inflammation,cell apoptosis,phosphorylation,and nuclear translocation of NF-κB p65.Conclusion:SLC26A4 exhibited promoting effects on myocardial IR injury,while the SLC26A4 knockdown had an inhibitory effect on the NF-κB pathway.These results further unveil the role of SLC26A4 in IR injury.

Long non-coding RNA-AK138945 regulates myocardial ischemia-reperfusion injury via the miR-1-GRP94 signaling pathway

Objective:Myocardial ischemia-reperfusion injury(MIRI)is one of the leading causes of death from cardiovascular disease in humans,especially in individuals exposed to cold environments.Long non-coding RNAs(lncRNAs)regulate MIRI through multiple mechanisms.This study explored the regulatory effect of lncRNA-AK138945 on myocardial ischemia-reperfusion injury and its mechanism.Methods:In vivo,8-to 12-weeks-old C57BL/6 male mice underwent ligation of the left anterior descending coronary artery for 50 minutes followed by reperfusion for 48 hours.In vitro,the primary cultured neonatal mouse ventricular cardiomyocytes(NMVCs)were treated with 100μmol/L hydrogen peroxide(H_(2)O_(2)).The knockdown of lncRNA-AK138945 was evaluated to detect cardiomyocyte apoptosis,and a glucose-regulated,endoplasmic reticulum stress-related protein 94(GRP94)inhibitor was used to detect myocardial injury.Results:We found that the expression level of lncRNA-AK138945 was reduced in MIRI mouse heart tissue and H2O2-treated cardiomyocytes.Moreover,the proportion of apoptosis in cardiomyocytes increased after lncRNA-AK138945 was silenced.The expression level of Bcl2 protein was decreased,and the expression level of Bad,Caspase 9 and Caspase 3 protein was increased.Our further study found that miR-1a-3p is a direct target of lncRNA-AK138945,after lncRNA-AK138945 was silenced in cardiomyocytes,the expression level of miR-1a-3p was increased while the expression level of its downstream protein GRP94 was decreased.Interestingly,treatment with a GRP94 inhibitor(PU-WS13)intensified H2O2-induced cardiomyocyte apoptosis.After overexpression of FOXO3,the expression levels of lncRNA-AK138945 and GRP94 were increased,while the expression levels of miR-1a-3p were decreased.Conclusion:LncRNA-AK138945 inhibits GRP94 expression by regulating miR-1a-3p,leading to cardiomyocyte apoptosis.The transcription factor Forkhead Box Protein O3(FOXO3)participates in cardiomyocyte apoptosis induced by endoplasmic reticulum stress through up-regulation of lncRNA-AK138945.

Therapeutic Effects and Potential Mechanisms of Glyasperin A against Myocardial Ischemia Based on Network Pharmacology and Molecular Docking

[Objectives]To explore the therapeutic effects and potential mechanisms of Glyasperin A(GAA)on myocardial ischemia(MI)based on network pharmacology and molecular docking.[Methods]The molecular structure of GAA was downloaded from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP),and all targets of GAA were predicted by converting 3D model molecules into SMILES online tool and Swiss target prediction.Genecards database and DisGeNET database were used to find the targets related to MI,and then Venny 2.1.0 was used to generate the corresponding Wayne diagram,and then Cytoscape 3.9.1 software was used to construct the protein-protein interaction(PPI)network.With the help of DAVID database and Microbiology,the selected core targets were enriched and analyzed by gene ontology(GO),biological process(BP),and Kyoto Encyclopedia of Genes and Genomes(KEGG),and then the molecular docking between GAA and core targets was verified by AutoDock and Pymol software.[Results]A total of 1883 MI targets were screened,and in the protein-protein interaction network,AKT1,PTGS2,PPARG,ESR1,GSK3B were the proteins with higher values.Gene ontology and KEEG enrichment analysis showed that the biological processes involved mainly included inflammatory response,negative regulation of gene expression,and response to exogenous stimuli.Signaling pathways mainly include IL-17 signaling pathway,HIF-1 signaling pathway,and so on.The results of molecular docking showed that the binding energy of GAA and core protein was less than-5 Kcal/mol in four groups.These indicated that GAA with good binding had a certain therapeutic effect on myocardial ischemia.[Conclusions]Based on the systematic network pharmacology method,this study predicts the basic pharmacological effects and potential mechanisms of GAA in the treatment of MI,and reveals that GAA may treat MI through multiple targets and signaling pathways.It is expected to provide a basis for further study of its pharmacological mechanisms.

Canonical transient receptor potential channel 1 aggravates myocardial ischemia-and-reperfusion injury by upregulating reactive oxygen species

The canonical transient receptor potential channel(TRPC)proteins form Ca^(2+)-permeable cation channels that are involved in various heart diseases.However,the roles of specific TRPC proteins in myocardial ischemia/reperfusion(I/R)injury remain poorly understood.We observed that TRPC1 and TRPC6 were highly expressed in the area at risk(AAR)in a coronary artery ligation induced I/R model.Trpc1/mice exhibited improved cardiac function,lower serum Troponin T and serum creatine kinase level,smaller infarct volume,less fibrotic scars,and fewer apoptotic cells after myocardial-I/R than wild-type or Trpc6/mice.Cardiomyocyte-specific knockdown of Trpc1 using adeno-associated virus 9 mitigated myocardial I/R injury.Furthermore,Trpc1 deficiency protected adult mouse ventricular myocytes(AMVMs)and HL-1 cells from death during hypoxia/reoxygenation(H/R)injury.RNA-sequencing-based transcriptome analysis revealed differential expression of genes related to reactive oxygen species(ROS)generation in Trpc1/cardiomyocytes.Among these genes,oxoglutarate dehydrogenase-like(Ogdhl)was markedly downregulated.Moreover,Trpc1 deficiency impaired the calcineurin(CaN)/nuclear factorkappa B(NF-kB)signaling pathway in AMVMs.Suppression of this pathway inhibited Ogdhl upregulation and ROS generation in HL-1 cells under H/R conditions.Chromatin immunoprecipitation assays confirmed NF-kB binding to the Ogdhl promoter.The cardioprotective effect of Trpc1 deficiency was canceled out by overexpression of NF-kB and Ogdhl in cardiomyocytes.In conclusion,our findings reveal that TRPC1 is upregulated in the AAR following myocardial I/R,leading to increased Ca^(2+) influx into associated cardiomyocytes.Subsequently,this upregulates Ogdhl expression through the CaN/NF-kB signaling pathway,ultimately exacerbating ROS production and aggravating myocardial I/R injury.

Flow cytometric analysis of circulating microvesicles derived from myocardial ischemic preconditioning and cardioprotection of ischemia/reperfusion injury in rats

Objective: To establish a flow cytometric method to detect the alteration of phenotypes and concentration of circulating microvesicles(MVs) from myocardial ischemic preconditioning(IPC) treated rats(IPC-MVs), and to investigate the effects of IPC-MVs on ischemia/reperfusion(I/R) injury in rats. Methods: Myocardial IPC was elicited by three cycles of 5-min ischemia and 5-min reperfusion of the left anterior descending(LAD) coronary artery. Platelet-free plasma(PFP) was isolated through two steps of centrifugation at room temperature from the peripheral blood, and IPC-MVs were isolated by ultracentrifugation from PFP. PFP was incubated with anti-CD61, anti-CD144, anti-CD45 and anti-Erythroid Cells, and added 1, 2 μm latex beads to calibrate and absolutely count by flow cytometry. For functional research, I/R injury was induced by 30-min ischemia and 120-min reperfusion of LAD. IPC-MVs 7 mg/kg were infused via the femoral vein in myocardial I/R injured rats. Mean arterial blood pressure(MAP), heart rate(HR) and ST-segment of electrocardiogram(ECG) were monitored throughout the experiment. Changes of myocardial morphology were observed after hematoxylin-eosin(HE) staining. The activity of plasma lactate dehydrogenase(LDH) was tested by Microplate Reader. Myocardial infarct size was measured by TTC staining. Results: Total IPC-MVs and different phenotypes, including platelet-derived MVs(PMVs), endothelial cell-derived MVs(EMVs), leucocyte-derived MVs(LMVs) and erythrocyte-derived MVs(RMVs) were all isolated which were identified membrane vesicles(<1 μm) with corresponding antibody positive. The numbers of PMVs, EMVs and RMVs were significantly increased in circulation of IPC treated rats(P<0.05, respectively). In addition, at the end of 120-min reperfusion in I/R injured rats, IPC-MVs markedly increased HR(P<0.01), decreased ST-segment and LDH activity(P<0.05, P<0.01). The damage of myocardium was obviously alleviated and myocardial infarct size was significantly lowered after IPC-MVs treatment(P<0.01). Conclusion: The method of flow cytometry was successfully established to detect the phenotypes and concentration alteration of IPC-MVs, including PMVs, EMVs, LMVs and RMVs. Furthermore, circulating IPC-MVs protected myocardium against I/R injury in rats.

Atorvastatin Alleviates Myocardial Ischemia-Reperfusion Injury via miR-26a-5p/FOXO1

Purpose: Ischemia-reperfusion (I/R) injury exacerbates myocardial cell death (including apoptosis and necrosis), leading to complications such as arrhythmias, myocardial stenosis, microvascular obstruction and heart failure, and it is particularly important to seek new strategies to mitigate reperfusion injury. In this paper, we will investigate whether atorvastatin can alleviate myocardial ischemia-reperfusion injury and verify its molecular mechanism. Methods: We successfully constructed a hypoxia-reperfusion (H/R) H9c2 cell model and transfected miR-26a-5p mimic, miR-26a-5p inhibitor and its negative control NC-mimic or NC-inhibitor into H9c2 cells using a transfection kit. The expression of miR-26a-5p and FOXO1 were detected by RT-qPCR assay, the expression of related proteins by Western blot assay, the cell viability of H9c2 cells by CCK-8 assay, the apoptosis rate of H9c2 cells by flow cytometry, the CK and LDH activity in cells by CK and LDH assay kits. The targeting relationship between miR-26a-5p and FOXO1 was verified by dual luciferase reporter gene assay. Results: MiR-26a-5p expression was decreased in H/R-induced cells and FOXO1 expression was increased in H/R-induced cells. Atorvastatin alleviated H/R injury in cardiomyocytes and was most effective at a concentration of 1 μM. Atorvastatin alleviated H/R injury in cardiomyocytes by upregulating miR-26a-5p expression, miR-26a-5p and FOXO1 were negatively regulated by targeting. Conclusion: Atorvastatin can alleviate H/R injury in cardiomyocytes by regulating miR-26a-5p/FOXO1.

Protective Effect of Electroacupuncture and Ischemic Preconditioning on the Circulatory Function in Pigs with Ischemia/Reperfusion Myocardial Injury

Objective: To investigate the effects of electroacupuncture and ischemic preconditioning (IPC) on circulatory function in pigs with myocardial ischemia/reperfusion injury. Method: Eighteen pigs with myocardial ischemia/reperfusion injury were randomly allocated into three groups, 6 in each. Group I was the control group, group II was the group that received IPC, and group III was that received both electroacupuncture and IPC. Blood malondialdehyde (MDA), superoxide dismutase (SOD), creatine phos-phokinase (CPK) and its isoenzyme (CK-MB), coronary artery flow and myocardial heat-shock protein (HSP) mRNA expression were detected for evaluation. Results: After treatment, the MDA content was decreased and SOD activities increased significantly in the acupuncture and IPC group compared with the control group (P<0. 05 respectively). The levels of CPK, CK-MB at 20, 60 min after reperfusion were significantly higher than those before treatment, but the levels in group III and group n were remarkably lower than those in group I . HSP70 mRNA expression was found to be increased in group II and group III at 60 min after ischemia/reperfusion compared with those in group I . Conclusion: Electroacupuncture can enhance the myocardial protection of IPC against ischemia/reperfusion injury. The.protective mechanism may be related to the improvement of antioxidation and the increased expression of HSP70 gene.

Acupuncture preconditioning protects against myocardial ischemia/reperfusion injury mediated apoptosis through miR-214/NCX1 activation: a hypothesis

Early reperfusion of ischemic cardiac tissue is usually the best option to improve clinical outcome of angina pectoris, especially of acute myocardial infarction. However, myocardial reperfusion may cause an abnormal increase of intracellular Ca^2+-mediated cardiomyocyte death and consequent loss of cardiac function, which is referred to myocardial ischemia/reperfusion (I/R) injury. Recently, the microRNA-214 (miR-214)/Na^+/Ca^2+ exchanger (NCX) 1 co-expression is a key factor in cellular protection against myocardial apoptosis for myocardial I/R injury. Once activated, miR-214/NCX1 axis can inhibit several Ca^2+ downstream signaling effectors that mediate cell death simultaneously. Studies have shown that acupuncture preconditioning has a protective effect on myocardial I/R injury, but its mechanism deserves further research. It has been proved that acupuncture preconditioning for ischemic myocardium successfully inhibit multiple Ca2+ handling related microRNAs that mediate cell death pathways, and miR-214 is one of its targets. In terms of clinical practice, coronary heart disease (CHD) patients benefit a lot from this intervention. However, there is barely no study correlating acupuncture preconditioning to the miR-214/NCX1 co-expression in patients with CHD. This review aims to discuss whether there is some evidence to justify a recommendation of acupuncture preconditioning in CHD patients as a non-pharmacological therapeutic method to activate the miR-214/NCX1 co-expression network model.

Research Progress on Myocardial Protection Strategies

Myocaridial protection aims to salvage myocardium from ischemia and reperfusion injury and to reduce infarct size and its consequences.After more than 30 years of development,the concept of ischemic preconditioning has evolved into"ischemic conditioning",a term that encompasses a number of related endogenous cardioprotective strategies,which can be applied either directly to the heart(ischemic preconditioning or postconditioning)or from afar,for example to a limb(remote ischemic preconditioning,preconditioning,or postconditioning).A variety of cardioprotective therapies have shown promising results in reducing infarct size and improving clinical outcomes in patients with ischemic heart disease.

The expression of oxidative stress genes related to myocardial ischemia reperfusion injury in patients with ST-elevation myocardial infarction

BACKGROUND:We aimed to investigate the gene expression of myocardial ischemia/reperfusion injury(MIRI)in patients with acute ST-elevation myocardial infarction(STEMI)using stress and toxicity pathway gene chip technology and try to determine the underlying mechanism.METHODS:The mononuclear cells were separated by ficoll centrifugation,and plasma total antioxidant capacity(T-AOC)was determined by the ferric reducing ability of plasma(FRAP)assay.The expression of toxic oxidative stress genes was determined and verified by oligo gene chip and quantitative real-time polymerase chain reaction(qRT-PCR).Additionally,gene ontology(GO)enrichment analysis was performed on DAVID website to analyze the potential mechanism further.RESULTS:The total numbers of white blood cells(WBC)and neutrophils(N)in the peripheral blood of STEMI patients(the AMI group)were significantly higher than those in the control group(WBC:11.67±4.85×10^(9)/L vs.6.41±0.72×10^(9)/L,P<0.05;N:9.27±4.75×10^(9)/L vs.3.89±0.81×10^(9)/L,P<0.05),and WBCs were significantly associated with creatine kinase-myocardial band(CK-MB)on the first day(Y=8.945+0.018X,P<0.05).In addition,the T-AOC was significantly lower in the AMI group comparing to the control group(12.80±1.79 U/mL vs.20.48±2.55 U/mL,P<0.05).According to the gene analysis,eight up-regulated differentially expressed genes(DEGs)included GADD45A,PRDX2,HSPD1,DNAJB1,DNAJB2,RAD50,TNFSF6,and TRADD.Four down-regulated DEGs contained CCNG1,CAT,CYP1A1,and ATM.TNFSF6 and CYP1A1 were detected by polymerase chain reaction(PCR)to verify the expression at different time points,and the results showed that TNFSF6 was up-regulated and CYP1A1 was down-regulated as the total expression.GO and kyoto encyclopedia of genes and genomes(KEGG)enrichment analysis suggested that the oxidative stress genes mediate MIRI via various ways such as unfolded protein response(UPR)and apoptosis.CONCLUSIONS:WBCs,especially neutrophils,were the critical cells that mediating reperfusion injury.MIRI was regulated by various genes,including oxidative metabolic stress,heat shock,DNA damage and repair,and apoptosis-related genes.The underlying pathway may be associated with UPR and apoptosis,which may be the novel therapeutic target.

Impaired tricarboxylic acid cycle flux and mitochondrial aerobic respiration during isoproterenol induced myocardial ischemia is rescued by bilobalide

There is an urgent need to elucidate the pathogenesis of myocardial ischemia(MI)and potential drug treatments.Here,the anti-MI mechanism and material basis of Ginkgo biloba L.extract(GBE)were studied from the perspective of energy metabolism flux regulation.Metabolic flux analysis(MFA)was performed to investigate energy metabolism flux disorder and the regulatory nodes of GBE components in isoproterenol(ISO)-induced ischemia-like cardiomyocytes.It showed that[U-13 C]glucose derived m+2 isotopologues from the upstream tricarboxylic acid(TCA)cycle metabolites were markedly accumulated in ISO-injured cardiomyocytes,but the opposite was seen for the downstream metabolites,while their total cellular concentrations were increased.This indicates a blockage of carbon flow from glycolysis and enhanced anaplerosis from other carbon sources.A Seahorse test was used to screen for GBE components with regulatory effects on mitochondrial aerobic respiratory dysfunction.It showed that bilobalide protected against impaired mitochondrial aerobic respiration.MFA also showed that bilobalide significantly modulated the TCA cycle flux,reduced abnormal metabolite accumulation,and balanced the demand of different carbon sources.Western blotting and PCR analysis showed that bilobalide decreased the enhanced expression of key metabolic enzymes in injured cells.Bilobalide’s efficacy was verified by in vivo experiments in rats.This is the first report to show that bilobalide,the active ingredient of GBE,protects against MI by rescuing impaired TCA cycle flux.This provides a new mechanism and potential drug treatment for MI.It also shows the potential of MFA/Seahorse combination as a powerful strategy for pharmacological research on herbal medicine.

The evolving concept of physiological ischemia training vs. ischemia preconditioning

Ischemic heart diseases are the leading cause of death with increasing numbers of patients worldwide. Despite advances in revascularization techniques, angiogenic therapies remain highly attractive. Physiological ischemia train- ing, which is first proposed in our laboratory, refers to reversible ischemia training of normal skeletal muscles by using a tourniquet or isometric contraction to cause physiologic ischemia for about 4 weeks for the sake of triggering mole- cular and cellular mechanisms to promote angiogenesis and formation of collateral vessels and protect remote ische- mia areas. Physiological ischemia training therapy augments angiogenesis in the ischemic myocardium by inducing differential expression of proteins involved in energy metabolism, cell migration, protein folding, and generation. It upregulates the expressions of vascular endothelial growth factor, and induces angiogenesis, protects the myocardium when infarction occurs by increasing circulating endothelial progenitor cells and enhancing their migration, which is in accordance with physical training in heart disease rehabilitation. These findings may lead to a new approach of ther- apeutic angiogenesis for patients with ischemic heart diseases. On the basis of the promising results in animal studies, studies were also conducted in patients with coronary artery disease without any adverse effect in vivo, indicating that physiological ischemia training therapy is a safe, effective and non-invasive angiogenic approach for cardiovascular rehabilitation. Preconditioning is considered to be the most protective intervention against myocardial ischemia-reper- fusion injury to date. Physiological ischemia training is different from preconditioning. This review summarizes the preclinical and clinical data of physiological ischemia training and its difference from preconditioning.

Revascularization and outcomes in Veterans with moderate to severe ischemia on myocardial perfusion imaging

Background： The prevalence of ischemia on nuclear myocardial perfusion imaging （MPI） has been decreasing. Recent research has questioned the benefit of invasive revascularization for patients with moderate to severe ischemia. We hypothesized that patients with moderate to severe ischemia could routinely undergo successful revascularization. Methods： We analyzed data from 544 patients who underwent an MPI at a single academic Veterans Affairs Medical Center. Patients with moderate to severe ischemia, defined as a summed difference score （SDS） 8 or greater, were compared to the rest of the cohort. Results： Of the total cohort （n=544）, 39 patients had MPI studies with resultant moderate to severe ischemia. Patients with ischemia were more likely to develop coronary artery disease （74.4% versus 38.8%, P〈0.0001） and have successful revascularization （38.5% versus 4.0%, P〈0.0001） during the following year. Revascularization was attempted in 31 patients with moderate to severe ischemia, though only 15（47%） of these attempts were successful, Ischemia was predictive of myocardial infarction （5.1% versus 0.8%, P=0.01） within I year. Conclusion： Moderate to severe ischemia is an uncommon finding in a contemporary nuclear laboratory. Among patients with ischemia, revascularization is typically attempted but is frequently unsuccessful. Trial registration： This trial does not appear on a registry as it is neither randomized nor prospective.

The role of glycogen synthase kinase 3 beta in brain injury induced by myocardial ischemia/reperfusion injury in a rat model of diabetes mellitus

Myocardial ischemia/reperfusion injury can lead to severe brain injury.Glycogen synthase kinase 3 beta is known to be involved in myocardial ischemia/reperfusion injury and diabetes mellitus.However,the precise role of glycogen synthase kinase 3 beta in myocardial ischemia/reperfusion injury-induced brain injury is unclear.In this study,we observed the effects of glycogen synthase kinase 3 beta on brain injury induced by myocardial ischemia/reperfusion injury in diabetic rats.Rat models of diabetes mellitus were generated via intraperitoneal injection of streptozotocin.Models of myocardial ischemia/reperfusion injury were generated by occluding the anterior descending branch of the left coronary artery.Post-conditioning comprised three cycles of ischemia/reperfusion.Immunohistochemical staining and western blot assays demonstrated that after 48 hours of reperfusion,the structure of the brain was seriously damaged in the experimental rats compared with normal controls.Expression of Bax,interleukin-6,interleukin-8,terminal deoxynucleotidyl transferase d UTP nick end labeling,and cleaved caspase-3 in the brain was significantly increased,while expression of Bcl-2,interleukin-10,and phospho-glycogen synthase kinase 3 beta was decreased.Diabetes mellitus can aggravate inflammatory reactions and apoptosis.Ischemic post-conditioning with glycogen synthase kinase 3 beta inhibitor lithium chloride can effectively reverse these changes.Our results showed that myocardial ischemic post-conditioning attenuated myocardial ischemia/reperfusion injury-induced brain injury by activating glycogen synthase kinase 3 beta.According to these results,glycogen synthase kinase 3 beta appears to be an important factor in brain injury induced by myocardial ischemia/reperfusion injury.

Experimental Study of the Effect of Autonomic Nervous System on the Transmural Dispersion of Ventricular Repolarization under Acute Myocardial Ischemia in Vivo

The effect of the autonomic nerves on the transmural dispersion of ventricular repolarization(TDR)under acute myocardial ischemia in intact canine was investigated.Using the monophasic action potential(MAP)recording technique,MAPs of the epicardium(Epi),midmyocardium(Mid)and endocardium(Endo)were recorded simultaneously by specially designed plunge-needle electrodes at the left ventricular free wall under acute myocardial ischemia in 12 open-chest dogs.MAPD 90 and TDR among three myocardial layers as well as the incidence of the early afterdepolarization(EAD)before autonomic nervous stimulation and during autonomic nervous stimulation were compared.It was found that 10 min after acute myocardial ischemia,TDR was increased from 55±8 ms to 86±15 ms during sympathetic stimulation(P<0.01).The TDR(53±9 ms)during parasympathetic stimulation was not significantly different from that of the control(55±8 ms)(P>0.05).The EAD was elicited in the Mid of 2 dogs(16%)10 min after acute myocardial ischemia,but the EAD were elicited in the Mid of 7 dogs(58%)during sympathetic stimulation(P<0.01).It was concluded that:(1)Sympathetic stimulation can increase the transmural dispersion of repolari-zation and induce early afterdepolarizations in the Mid under acute myocardial ischemia,which provide the opportunity for the ventricular arrhythmia developing;(2)Parasympathetic stimulation has no significant effect on the transmural dispersion of repolarization under myocardial ischemia.

EFFECT OF ELECTROACUPUNCTURE OF ACUPOINTS OF THE HEART MERIDIAN ON ECG, SMALL INTESTINAL ELECTROGRAM AND EEG IN THE RABBIT WITH MYOCARDIAL ISCHEMIA

In the present paper, effects of electroacupuncture (EA) of 3 points of the Heart Meridian and other 3 points of the Lung Meridian on changes of electrocardiogram (ECG), small intestinal electrogram (SIG) and electroencephalogram (EEG) in intravenous drip of pituitrin induced myocardial ischemia rabbits. The three points of the Heart Meridian are "Shenmen" (HT 7), "Lingdao" (HT 4) and one point between HT 7 and HT 4, the 3 points of the Lung Meridian are "Taiyuan"(LU 9), Lieque (LU 7) and one point between LU 9 and LU 7. These points are punctured with filiform needles and stimulated electrically by setting the parameters being frequency of 2.5 Hz, dense sparse waves and duration of 10 min. Results display that the regulative effect of EA of the Heart Meridian is superior to that of EA of the Lung Meridian on the three indexes, showing a closer correlation between the whole Heart Meridian and activities of ECG, SIG and EEG.

Protective Effects of Zingiberis and Acniti Praeparatae Decoction on Myocardial IschemiaReperfusion Injury in Rats

This study aimed to investigate the protective effects of zin-giberis and acniti praeparatae decoction on oxidative stress injury induced by my-ocardial ischemia reperfusion in rats. [Method] Myocardial ischemia-reperfusion was performed by ligation of the left anterior descending coronary artery for 30 min, fol-lowed by reperfusion for 60 min. The effects of zingiberis and acniti praeparatae decoction on ECG ST segment, myocardial infarction percentage, malondialdehyde （MDA） content in the serum, superoxide dismutase （SOD） activity and other indica-tors were observed. [Result] Zingiberis and acniti praeparatae decoction could effec-tively inhibit ECG ST segment elevation caused by myocardial ischemia-reperfusion injuries, reduce the percentage of myocardial infarction, decline the content of MDA in the serum, and increase the activity of SOD. [Conclusion] Zingiberis and acniti praeparatae decoction exhibits protective effects on oxidative injuries caused by my-ocardial ischemia-reperfusion injuries in rats, which may be involved in reducing the formation of myocardial free radicals and enhancing antioxidant capacity of my-ocardium.

Is there a role for ischemia detection after an acute myocardial infarction?

Coronary angiography and eventual revascularization have become the most common approaches for patients with acute coronary syndromes.Ischemia detection in this scenario is usually regarded as unnecessary for most of the patients.In fact,current guidelines recommend complete revascularization for patients with multivessel disease in the context of ST-elevation myocardial infarction,although it is in contrast with previous recommendations.However,some recent data suggested that ischemia could have a role for the decision of revascularization in these patients.The CROSS-AMI study randomized patients with ST-elevation myocardial infarction treated with primary angioplasty and who also had multivessel disease to a complete anatomic revascularization of the non-infarct related artery lesions vs subsequent revascularization of the noninfarct related artery lesions only if ischemia was demonstrated by stress echocardiography.The main findings were that only 30%of the patients in the ischemia arm needed a second revascularization and that the outcome was similar in both arms.Regarding non-ST-elevation acute coronary syndrome,coronary angiography is in general warranted for most of the patients.However,recent long-term published studies on patients randomized to an invasive or less aggressive approach based on ischemia detection have found no differences in outcome.The ultimate study in non-ST-elevation acute coronary syndrome comparing ischemia detection with an invasive approach is pending.Therefore,ischemia detection might have a role for stratifying these subjects.This is particularly true in the current era of imaging of high quality and sensitivity,last generation stents,radial access and modern antithrombotic therapy.