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 i...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.展开更多
This study examined the protective effect of ischemic postconditioning(IPoC) and minocycline postconditioning(MT) on myocardial ischemia-reperfusion(I/R) injury in atherosclerosis(AS) animals and the possible mechanis...This study examined the protective effect of ischemic postconditioning(IPoC) and minocycline postconditioning(MT) on myocardial ischemia-reperfusion(I/R) injury in atherosclerosis(AS) animals and the possible mechanism.Forty male healthy rabbits were injected with bovine serum albumin following feeding on a high fat diet for 6 weeks to establish AS model.AS rabbits were randomly divided into 3 groups:(1) I/R group,the rabbits were subjected to myocardial ischemia for 35 min and then reperfusion for 12 h;(2) IPoC group,the myocardial ischemia lasted for 35 min,and then reperfusion for 20 s and ischemia for 20 s [a total of 3 cycles(R20s/I20s×3)],and then reperfusion was sustained for 12 h;(3) MT group,minocycline was intravenously injected 10 min before reperfusion.The blood lipids,malondialdehyde(MDA),superoxide dismutase(SOD),soluble cell adhesion molecule(sICAM),myeloperoxidase(MPO),and cardiac troponin T(cTnT) were biochemically determined.The myocardial infarction size(IS) and apoptosis index(AI) were measured by pathological examination.The expression of bcl-2 and caspase-3 was detected in the myocardial tissue by using reverse transcription-polymerase chain reaction(RT-PCR).The results showed that the AS models were successfully established.The myocardial IS,the plasma levels of MDA,sICAM,MPO and cTnT,and the enzymatic activity of MPO were significantly decreased,and the plasma SOD activity was significantly increased in IPoC group and MT group as compared with I/R group(P<0.05 for all).The myocardial AI and the caspase-3 mRNA expression were lower and the bcl-2 mRNA expression was higher in IPoC and MT groups than those in I/R group(all P<0.05).It is concluded that the IPoC and MT can effectively reduce the I/R injury in the AS rabbits,and the mechanisms involved anti-oxidation,anti-inflammation,up-regulation of bcl-2 expression and down-regulation of caspase-3 expression.Minocycline can be used as an effective pharmacologic postconditioning drug to protect myocardia from I/R injury.展开更多
Objective The purpose of this study is to investgate changes of cTnI in myocardial ischemic and reperfusion injury during correction of cardiac defects in children. Methods From June, 1999 to May,2000,45 children (30 ...Objective The purpose of this study is to investgate changes of cTnI in myocardial ischemic and reperfusion injury during correction of cardiac defects in children. Methods From June, 1999 to May,2000,45 children (30 male, 15 female) undergoing correction of cardiac defects were divided into three groups randomly: group Ⅰ no myocardial ischemia,group Ⅱ myocardial ischemia less than 60 minutes, group Ⅲmyocardial ischemia 】 60 minutes. There were no significant differences in the three groups in age, sex ratio, C/T ratio, or left ventricular function. Blood samples for analysis were collected before skin incision and at time intervals up to 6 days postoperatively. Analysis of creatine kinase MB.LDH and cardiac-specific troponin I was used for the detection of myocardial damage. Meantime, the ECG was checked for myocardial infarction. After the reperfusion, myocardial tissue was obtained from the free wall of right ventricle myocardial structure studies. Results The level of cTnI was increased展开更多
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 o...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.展开更多
Emerging evidence indicates that ischemic preconditioning （IPC） induces autophagy which attenuates myocardial ischemia/reperfusion （I/R） injury. However, the precise mechanisms remain com- plex and unclear. The pr...Emerging evidence indicates that ischemic preconditioning （IPC） induces autophagy which attenuates myocardial ischemia/reperfusion （I/R） injury. However, the precise mechanisms remain com- plex and unclear. The present study was to investigate which autophagy pathway was involved in the cardioprotection induced by IPC, so that we can acquire an attractive treatment way for iscbemic heart disease. Adult male Sprague-Dawley （SD） rats were randomly divided into sham group, I/R group and IPC group. IPC was induced with three cycles of 5 min regional ischemia alternating with 5 m^n reper- fusion in a heart I/R model. Samples were taken from the center of the infracted heart and examined by using the electron microscopy, the terminal deoxynucleotidyl transferase-mediated nick end-labeling （TUNEL） method, Western blotting and co-immunoprecipitation （Co-IP）. A large number of autophagic vacuoles were observed in the cardiomyocytes oflPC group as compared with I/R group. LC3-II forma- tion, an autophagy marker, was up-regulated in IPC group as compared with FR group （P〈0.05）. Moreover, the interaction between Beclin 1 and Bcl-2 was significantly increased in IPC group as com- pared with I/R group （P〈0.01）. It was also found that IPC decreased I/R-induced apoptosis （P〈0.01）. These results suggest that IPC inhibits Beclin 1-dependent excessive autophagy in reperfusion phase and cooperates with anti-apoptosis pathway to diminish the cell death induced by the myocardial I/R injury.展开更多
Background Whether plasma can transfer the protective effect（s） of remote ischemic preconditioning （RIPC） between animals remains unresolved. We therefore investigated the effects of plasma collected 48 hours afte...Background Whether plasma can transfer the protective effect（s） of remote ischemic preconditioning （RIPC） between animals remains unresolved. We therefore investigated the effects of plasma collected 48 hours after transient limb ischemia on blood pressure recovery during myocardial ischemia reperfusion （IR） in homogenic rats. Methods Plasma was collected from Lewis rats, and the donor rats were randomly assigned to 2 groups： transient limb ischemia and control （n = 8 each）. Transient limb ischemia was achieved by four cycles of 5-minute ischemia and 5-minute reperfusion by noninvasive ligation and deligation of the both legs using elastic rubber bands after anesthesia. In the control group, no ligation was performed. Forty-eight hours later, whole blood was collected, and the plasma spun off. Study Lewis rats underwent 30-minute left anterior descending coronary artery occlusion followed by 180-minute reperfusion, and were randomly assigned to 2 groups （group A and group B, n = 24 each）, each further subdivided into 3 subgroups （n = 8 each）. The subgroups of group A received normal saline （group A1）, plasma of control rats （group A2）, plasma of transient limb ischemia rats （group A3） respectively at 1 hour before IR; the subgroups of group B received normal saline （group B1）, plasma of control rats （group B2）, plasma of transient limb ischemia rats （group B3） respectively at 24 hours before IR. BIOPAC systems were used to measure hemodynamics of rats during myocardial ischemia- reperfusion. Results Systolic blood pressure （SBP） after IR in group B3 was different from that in groups B1 and B2 （B3 vs. B1, ,~=-0.007; B3 vs. B2, P =0.039） at the beginning of reperfusion and 30 minutes after reperfusion. SBP was higher in group B3 than in groups B1 and B2 at the beginning of perfusion （B3 vs. B1, P=-0.010; B3 vs. B2, P=-0.002） and 30 minutes after reperfusion （B3 vs. B1, P=-0.001; B3 vs. B2, P=0.001）. SBP did not differ among subgroups A1, A2 and A3. Diastolic blood pressure and heart rate did not change in group A or group B. Conclusions The transfusion of plasma collected 48 hours after transient limb ischemia into homogenic rats 24 hours before IR can improve the SBP recovery during reperfusion. This may suggest that cardioprotective effect of late phase of RIPC is transferable via plasma.展开更多
Background： Plasma transfusion is a common clinical practice. Remote ischemic preconditioning （RIPC） protects organs against ischemia-reperfusion （IR） injury. Whether preconditioned plasma （PP）, collected at la...Background： Plasma transfusion is a common clinical practice. Remote ischemic preconditioning （RIPC） protects organs against ischemia-reperfusion （IR） injury. Whether preconditioned plasma （PP）, collected at late phase after RIPC, could protect organs against IR injury in vivo is unknown. This study explored whether transfusion of PP could reduce myocardial inihrct size （IS） after I R in rat in vivo. Methods： Eighty Lewis rats were randomized to eight groups （n= 10 for each group）. Two groups of plasma donor rats donated plasma at 48 h after transient limb ischemia （PP） or control protocol （nonpreconditioned plasma [NPP]）. Six groups of recipient rats received normal saline （NS; NS-IR 1, and NS-1R 24 groups）, NPP （NPP-IR I and NPP-1R 24 groups）, or PP （PP-IR 1 and PP-IR 24 groups） at one or 24 h before myocardial IR. Myocardial IR consisted of 30-min left anterior descending （LAD） coronary artery occlusion and 180-rain reperIhsion. The area at risk （AAR） and infarct area were determined by double-staining with Evans blue and triphenyltetrazolium chloride. IS was calculated by inihrct area divided by AAR. This was a 3 × 2 factorial design study, and factorial analysis was used to evaluate the data. If an interaction between the fluid and transfusion time existed, one-way analysis of variance with Bonferroni correction lbr multiple comparisons was used to analyze the single effects of fluid type when the transfusion time was fixed. Results： IS in the NPP-IR I and PP-IR1 groups was smaller than in the NS-IR I group （F - 6.838, P = 0.005; NPP-IR I： 57 ± 8% vs. NS-IRI： 68± 6%, t = 2.843, P - 0.020; PP-IR I： 56 ~ 8% vs. NS-IR 1：68 ~ 6%, t - 3.102, P - 0.009）, but no significant difference was detected between the NPP-IR 1 and PP-IR 1 groups （57 ± 8% vs. 56 ± 8%, t 0.069, P = 1.000）. IS in the N PP-IR 24 and PP-IR 24 groups was smaller than in the NS-IR 24 group （F - 24.796, P 〈 0.001： NPP-IR 24： 56% ± 7% vs. NS-IR 24：68 ± 7%, t = 3.102, P =0.026; PP-IR 24：40±9% vs. NS-IR 24：68±7%, t = 7.237, P 〈 0.001 ）; IS in the PP-IR 24 group was smaller than in the NPP-IR 24 group （40 ＋ 9% vs. 56±7%, t = 4.135, P = 0.002）. Conclusion： Transfusion of PP collected at late phase after remote ischemic preconditioning could reduce IS, suggesting that late-phase cardioprotection was transferable in vivo.展开更多
目的探讨长链非编码RNA(long non-coding RNA,lncRNA)肺腺癌转录子1(MALAT1)以及下游调控蛋白高迁移率族蛋白B1(High-mobility group protein box-1,HMGB1)在缺血后处理降低大鼠心肌缺血-再灌注损伤(ischemia/reperfusion injury,IRI)...目的探讨长链非编码RNA(long non-coding RNA,lncRNA)肺腺癌转录子1(MALAT1)以及下游调控蛋白高迁移率族蛋白B1(High-mobility group protein box-1,HMGB1)在缺血后处理降低大鼠心肌缺血-再灌注损伤(ischemia/reperfusion injury,IRI)中的作用。方法将24只大鼠饲养7天后,随机分成3组:假手术(Sham)组、缺血再灌注(ischemia/reperfusion,IR)组、缺血后处理(ischemic post-conditioning,IPO)组。模型构建完毕24 h进行检测大鼠血清中心肌肌钙蛋白I(cTnI)和白介素6(IL-6)表达水平,取材检测大鼠心肌梗死面积,检测大鼠心肌组织中MALAT1转录表达水平的差异,HMGB1、Toll样受体4(Toll-like receptor4,TLR4)蛋白含量差异。结果与Sham组比较,IR、IPO组血清中cTnI、IL-6水平明显升高,心肌梗死面积明显增加,心肌组织中MALAT1表达水平显著上调,HMGB1、TLR4水平明显升高(P<0.05)。与IR组比较,IPO组cTnI浓度显著降低,心肌梗死面积显著减小,心肌组织中lncRNA-MALAT1相对表达量降低,HMGB1、TLR4蛋白含量降低(P<0.05)。结论及时的缺血后处理可有效减缓大鼠心肌缺血-再灌注的损伤程度,其相关机制可能与抑制MALAT1调节控制HMGB1、TLR4表达水平之间有一定的关联。展开更多
Objective: To observe the myocardial protecting effects of Ginaton (Ginkgo biloba extract) on ischemic-reperfusion injured myocardium during cardiopulmonary bypass (CPB). Methods: Twenty patients selected undergoing m...Objective: To observe the myocardial protecting effects of Ginaton (Ginkgo biloba extract) on ischemic-reperfusion injured myocardium during cardiopulmonary bypass (CPB). Methods: Twenty patients selected undergoing mitral valvular replacement were randomly divided into two groups. Control group: 10 patients, intermittent intra-aortic infusion with cold St.Thomas solution during hypothermic CPB. Ginaton group: 10 patients, intermittent intra-aortic infusion with cold St. Thomas solution containing Ginaton (0.5 mg·kg -1). Changes of ultrastructure levels of adenosine triphosphate (ATP), malondialdehyde (MDA) and hemodynamic data were measured. Results: Hemodynamic parameters in the Ginaton group were maintained better than those in the control group. MDA in the control group was significantly elevated during ischemic-reperfusion (P<0.05), while in the Ginaton group, there were no obvious change. The levels of ATP and energy change in the Ginaton group were obviously higher than those in the control group at declamping aorta (P<0.05). The percentage of normal mitochondria and glycogen content were significantly higher in the Ginaton group than that in the control group at declamping aorta (P<0.05). Conclusion: Ginkgo biloba extract may provide a beneficial effect on myocardial protection in ultrastructural preservation, prevention of high energy phosphate depletion, reduction in free radicals production and improvement of myocardial function.展开更多
Objective: To identify the protective effects of hypovolemic hypotension preconditioning on cardiopulmonary function after myocardial ischemia/reperfusion injury and to explore the possible mechanism.Methods: Twenty-f...Objective: To identify the protective effects of hypovolemic hypotension preconditioning on cardiopulmonary function after myocardial ischemia/reperfusion injury and to explore the possible mechanism.Methods: Twenty-four male white rabbits were randomly assigned to two groups. In the control group, ischemia/reperfusion animals(Group I/R, n=10) were subjected to thirty-minute occlusion of left anterior descending coronary artery and two-hour reperfusion. Animals in hypovolemic hypotension preconditioning group (Group HHP, n=14) experienced brief systemic ischemia preconditioning through blood withdrawl to lower blood pressure to 40%-50% of the baseline before myocardial ischemia/reperfusion. Hemodynamic parameters were recorded. Blood sample was taken to measure superoxide dismutase (SOD), malondialdehyde (MDA) and nitrogen monoxide (NO) changes with blood gas analysis. Myocardium specimens were sampled to examine apoptosis-related gene interleukin-1 beta converting enzyme (ICE) mRNA. Results: Cardiac mechanical function and lung gas exchange remained stable in Group HHP with a significant increase in NO level; while in Group I/R without preconditioning, cardiopulmonary dysfunction was present after 2 h reperfusion associated with a significant reduction in NO formation and an increase in MDA (P<(0.001)). There was negative expression of ICE mRNA in the two groups.Conclusions: Hypovolemic hypotension preconditioning significantly improves cardiopulmonary function and increases NO formation and the protective benefit associated with hypovolemic hypotension preconditioning of the heart may be regulated through NO mediated mechanism.展开更多
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(20101202110005)the Natural Science Foundation of Tianjin(11JCZDJC18300)the Research Foundation of Tianjin Municipal Education Commission(20110106)
文摘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.
文摘This study examined the protective effect of ischemic postconditioning(IPoC) and minocycline postconditioning(MT) on myocardial ischemia-reperfusion(I/R) injury in atherosclerosis(AS) animals and the possible mechanism.Forty male healthy rabbits were injected with bovine serum albumin following feeding on a high fat diet for 6 weeks to establish AS model.AS rabbits were randomly divided into 3 groups:(1) I/R group,the rabbits were subjected to myocardial ischemia for 35 min and then reperfusion for 12 h;(2) IPoC group,the myocardial ischemia lasted for 35 min,and then reperfusion for 20 s and ischemia for 20 s [a total of 3 cycles(R20s/I20s×3)],and then reperfusion was sustained for 12 h;(3) MT group,minocycline was intravenously injected 10 min before reperfusion.The blood lipids,malondialdehyde(MDA),superoxide dismutase(SOD),soluble cell adhesion molecule(sICAM),myeloperoxidase(MPO),and cardiac troponin T(cTnT) were biochemically determined.The myocardial infarction size(IS) and apoptosis index(AI) were measured by pathological examination.The expression of bcl-2 and caspase-3 was detected in the myocardial tissue by using reverse transcription-polymerase chain reaction(RT-PCR).The results showed that the AS models were successfully established.The myocardial IS,the plasma levels of MDA,sICAM,MPO and cTnT,and the enzymatic activity of MPO were significantly decreased,and the plasma SOD activity was significantly increased in IPoC group and MT group as compared with I/R group(P<0.05 for all).The myocardial AI and the caspase-3 mRNA expression were lower and the bcl-2 mRNA expression was higher in IPoC and MT groups than those in I/R group(all P<0.05).It is concluded that the IPoC and MT can effectively reduce the I/R injury in the AS rabbits,and the mechanisms involved anti-oxidation,anti-inflammation,up-regulation of bcl-2 expression and down-regulation of caspase-3 expression.Minocycline can be used as an effective pharmacologic postconditioning drug to protect myocardia from I/R injury.
文摘Objective The purpose of this study is to investgate changes of cTnI in myocardial ischemic and reperfusion injury during correction of cardiac defects in children. Methods From June, 1999 to May,2000,45 children (30 male, 15 female) undergoing correction of cardiac defects were divided into three groups randomly: group Ⅰ no myocardial ischemia,group Ⅱ myocardial ischemia less than 60 minutes, group Ⅲmyocardial ischemia 】 60 minutes. There were no significant differences in the three groups in age, sex ratio, C/T ratio, or left ventricular function. Blood samples for analysis were collected before skin incision and at time intervals up to 6 days postoperatively. Analysis of creatine kinase MB.LDH and cardiac-specific troponin I was used for the detection of myocardial damage. Meantime, the ECG was checked for myocardial infarction. After the reperfusion, myocardial tissue was obtained from the free wall of right ventricle myocardial structure studies. Results The level of cTnI was increased
基金supported by the National Natural Science Foundation of China,No.81471844the Natural Science Foundation of Hubei Province of China,No.2016CFB167the Basic Scientific Research Foundation of Central Universities,No.2042017kf0147
文摘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.
基金supported by the Pathology Laboratory, Immunology Laboratory, General Surgery Laboratory and Animal Laboratory of Tongji Medical College,Huazhong University of Science and Technology
文摘Emerging evidence indicates that ischemic preconditioning （IPC） induces autophagy which attenuates myocardial ischemia/reperfusion （I/R） injury. However, the precise mechanisms remain com- plex and unclear. The present study was to investigate which autophagy pathway was involved in the cardioprotection induced by IPC, so that we can acquire an attractive treatment way for iscbemic heart disease. Adult male Sprague-Dawley （SD） rats were randomly divided into sham group, I/R group and IPC group. IPC was induced with three cycles of 5 min regional ischemia alternating with 5 m^n reper- fusion in a heart I/R model. Samples were taken from the center of the infracted heart and examined by using the electron microscopy, the terminal deoxynucleotidyl transferase-mediated nick end-labeling （TUNEL） method, Western blotting and co-immunoprecipitation （Co-IP）. A large number of autophagic vacuoles were observed in the cardiomyocytes oflPC group as compared with I/R group. LC3-II forma- tion, an autophagy marker, was up-regulated in IPC group as compared with FR group （P〈0.05）. Moreover, the interaction between Beclin 1 and Bcl-2 was significantly increased in IPC group as com- pared with I/R group （P〈0.01）. It was also found that IPC decreased I/R-induced apoptosis （P〈0.01）. These results suggest that IPC inhibits Beclin 1-dependent excessive autophagy in reperfusion phase and cooperates with anti-apoptosis pathway to diminish the cell death induced by the myocardial I/R injury.
文摘Background Whether plasma can transfer the protective effect（s） of remote ischemic preconditioning （RIPC） between animals remains unresolved. We therefore investigated the effects of plasma collected 48 hours after transient limb ischemia on blood pressure recovery during myocardial ischemia reperfusion （IR） in homogenic rats. Methods Plasma was collected from Lewis rats, and the donor rats were randomly assigned to 2 groups： transient limb ischemia and control （n = 8 each）. Transient limb ischemia was achieved by four cycles of 5-minute ischemia and 5-minute reperfusion by noninvasive ligation and deligation of the both legs using elastic rubber bands after anesthesia. In the control group, no ligation was performed. Forty-eight hours later, whole blood was collected, and the plasma spun off. Study Lewis rats underwent 30-minute left anterior descending coronary artery occlusion followed by 180-minute reperfusion, and were randomly assigned to 2 groups （group A and group B, n = 24 each）, each further subdivided into 3 subgroups （n = 8 each）. The subgroups of group A received normal saline （group A1）, plasma of control rats （group A2）, plasma of transient limb ischemia rats （group A3） respectively at 1 hour before IR; the subgroups of group B received normal saline （group B1）, plasma of control rats （group B2）, plasma of transient limb ischemia rats （group B3） respectively at 24 hours before IR. BIOPAC systems were used to measure hemodynamics of rats during myocardial ischemia- reperfusion. Results Systolic blood pressure （SBP） after IR in group B3 was different from that in groups B1 and B2 （B3 vs. B1, ,~=-0.007; B3 vs. B2, P =0.039） at the beginning of reperfusion and 30 minutes after reperfusion. SBP was higher in group B3 than in groups B1 and B2 at the beginning of perfusion （B3 vs. B1, P=-0.010; B3 vs. B2, P=-0.002） and 30 minutes after reperfusion （B3 vs. B1, P=-0.001; B3 vs. B2, P=0.001）. SBP did not differ among subgroups A1, A2 and A3. Diastolic blood pressure and heart rate did not change in group A or group B. Conclusions The transfusion of plasma collected 48 hours after transient limb ischemia into homogenic rats 24 hours before IR can improve the SBP recovery during reperfusion. This may suggest that cardioprotective effect of late phase of RIPC is transferable via plasma.
文摘Background： Plasma transfusion is a common clinical practice. Remote ischemic preconditioning （RIPC） protects organs against ischemia-reperfusion （IR） injury. Whether preconditioned plasma （PP）, collected at late phase after RIPC, could protect organs against IR injury in vivo is unknown. This study explored whether transfusion of PP could reduce myocardial inihrct size （IS） after I R in rat in vivo. Methods： Eighty Lewis rats were randomized to eight groups （n= 10 for each group）. Two groups of plasma donor rats donated plasma at 48 h after transient limb ischemia （PP） or control protocol （nonpreconditioned plasma [NPP]）. Six groups of recipient rats received normal saline （NS; NS-IR 1, and NS-1R 24 groups）, NPP （NPP-IR I and NPP-1R 24 groups）, or PP （PP-IR 1 and PP-IR 24 groups） at one or 24 h before myocardial IR. Myocardial IR consisted of 30-min left anterior descending （LAD） coronary artery occlusion and 180-rain reperIhsion. The area at risk （AAR） and infarct area were determined by double-staining with Evans blue and triphenyltetrazolium chloride. IS was calculated by inihrct area divided by AAR. This was a 3 × 2 factorial design study, and factorial analysis was used to evaluate the data. If an interaction between the fluid and transfusion time existed, one-way analysis of variance with Bonferroni correction lbr multiple comparisons was used to analyze the single effects of fluid type when the transfusion time was fixed. Results： IS in the NPP-IR I and PP-IR1 groups was smaller than in the NS-IR I group （F - 6.838, P = 0.005; NPP-IR I： 57 ± 8% vs. NS-IRI： 68± 6%, t = 2.843, P - 0.020; PP-IR I： 56 ~ 8% vs. NS-IR 1：68 ~ 6%, t - 3.102, P - 0.009）, but no significant difference was detected between the NPP-IR 1 and PP-IR 1 groups （57 ± 8% vs. 56 ± 8%, t 0.069, P = 1.000）. IS in the N PP-IR 24 and PP-IR 24 groups was smaller than in the NS-IR 24 group （F - 24.796, P 〈 0.001： NPP-IR 24： 56% ± 7% vs. NS-IR 24：68 ± 7%, t = 3.102, P =0.026; PP-IR 24：40±9% vs. NS-IR 24：68±7%, t = 7.237, P 〈 0.001 ）; IS in the PP-IR 24 group was smaller than in the NPP-IR 24 group （40 ＋ 9% vs. 56±7%, t = 4.135, P = 0.002）. Conclusion： Transfusion of PP collected at late phase after remote ischemic preconditioning could reduce IS, suggesting that late-phase cardioprotection was transferable in vivo.
文摘目的探讨长链非编码RNA(long non-coding RNA,lncRNA)肺腺癌转录子1(MALAT1)以及下游调控蛋白高迁移率族蛋白B1(High-mobility group protein box-1,HMGB1)在缺血后处理降低大鼠心肌缺血-再灌注损伤(ischemia/reperfusion injury,IRI)中的作用。方法将24只大鼠饲养7天后,随机分成3组:假手术(Sham)组、缺血再灌注(ischemia/reperfusion,IR)组、缺血后处理(ischemic post-conditioning,IPO)组。模型构建完毕24 h进行检测大鼠血清中心肌肌钙蛋白I(cTnI)和白介素6(IL-6)表达水平,取材检测大鼠心肌梗死面积,检测大鼠心肌组织中MALAT1转录表达水平的差异,HMGB1、Toll样受体4(Toll-like receptor4,TLR4)蛋白含量差异。结果与Sham组比较,IR、IPO组血清中cTnI、IL-6水平明显升高,心肌梗死面积明显增加,心肌组织中MALAT1表达水平显著上调,HMGB1、TLR4水平明显升高(P<0.05)。与IR组比较,IPO组cTnI浓度显著降低,心肌梗死面积显著减小,心肌组织中lncRNA-MALAT1相对表达量降低,HMGB1、TLR4蛋白含量降低(P<0.05)。结论及时的缺血后处理可有效减缓大鼠心肌缺血-再灌注的损伤程度,其相关机制可能与抑制MALAT1调节控制HMGB1、TLR4表达水平之间有一定的关联。
文摘Objective: To observe the myocardial protecting effects of Ginaton (Ginkgo biloba extract) on ischemic-reperfusion injured myocardium during cardiopulmonary bypass (CPB). Methods: Twenty patients selected undergoing mitral valvular replacement were randomly divided into two groups. Control group: 10 patients, intermittent intra-aortic infusion with cold St.Thomas solution during hypothermic CPB. Ginaton group: 10 patients, intermittent intra-aortic infusion with cold St. Thomas solution containing Ginaton (0.5 mg·kg -1). Changes of ultrastructure levels of adenosine triphosphate (ATP), malondialdehyde (MDA) and hemodynamic data were measured. Results: Hemodynamic parameters in the Ginaton group were maintained better than those in the control group. MDA in the control group was significantly elevated during ischemic-reperfusion (P<0.05), while in the Ginaton group, there were no obvious change. The levels of ATP and energy change in the Ginaton group were obviously higher than those in the control group at declamping aorta (P<0.05). The percentage of normal mitochondria and glycogen content were significantly higher in the Ginaton group than that in the control group at declamping aorta (P<0.05). Conclusion: Ginkgo biloba extract may provide a beneficial effect on myocardial protection in ultrastructural preservation, prevention of high energy phosphate depletion, reduction in free radicals production and improvement of myocardial function.
文摘Objective: To identify the protective effects of hypovolemic hypotension preconditioning on cardiopulmonary function after myocardial ischemia/reperfusion injury and to explore the possible mechanism.Methods: Twenty-four male white rabbits were randomly assigned to two groups. In the control group, ischemia/reperfusion animals(Group I/R, n=10) were subjected to thirty-minute occlusion of left anterior descending coronary artery and two-hour reperfusion. Animals in hypovolemic hypotension preconditioning group (Group HHP, n=14) experienced brief systemic ischemia preconditioning through blood withdrawl to lower blood pressure to 40%-50% of the baseline before myocardial ischemia/reperfusion. Hemodynamic parameters were recorded. Blood sample was taken to measure superoxide dismutase (SOD), malondialdehyde (MDA) and nitrogen monoxide (NO) changes with blood gas analysis. Myocardium specimens were sampled to examine apoptosis-related gene interleukin-1 beta converting enzyme (ICE) mRNA. Results: Cardiac mechanical function and lung gas exchange remained stable in Group HHP with a significant increase in NO level; while in Group I/R without preconditioning, cardiopulmonary dysfunction was present after 2 h reperfusion associated with a significant reduction in NO formation and an increase in MDA (P<(0.001)). There was negative expression of ICE mRNA in the two groups.Conclusions: Hypovolemic hypotension preconditioning significantly improves cardiopulmonary function and increases NO formation and the protective benefit associated with hypovolemic hypotension preconditioning of the heart may be regulated through NO mediated mechanism.
