Objective: To establish the rat model with myocardial hypoxia/reoxygenation (H/R) injury, and investigate the protective effect of EPO pretreatment on the myocardium. Methods: Sixty male adult Wistar rats were randoml...Objective: To establish the rat model with myocardial hypoxia/reoxygenation (H/R) injury, and investigate the protective effect of EPO pretreatment on the myocardium. Methods: Sixty male adult Wistar rats were randomly divided into 3 groups: control group, H/R group, and EPO group, 20 in each group. The rats in EPO group accepted injection of 5 000 U/kg recombinant human erythropoietin (RHuEPO) through vein, and the other rats accepted the injection of the same volume of saline. Twenty-four hours after the injection, rats in the EPO and H/R groups were put into the hypoxia environment for 12 h and then returned to the normoxic environment for 2 h, and then the samples of blood and myocardium were collected. Serum myocardial enzyme activity, apoptosis, ultrastructure, myocardial MDA contents, EPO receptor (EPOR) expression in cardiac myocytes and cardiac functions were tested. Results: EPOR expression was positive in cardiac myocytes of adult rat according to the result of immunonistochemitry assaying. Compared to those in H/R group, rats in EPO group presented lighter injury of myocardial ultrastructure, the reduction of serum myocardial enzyme activity, inhibition of apoptosis, the better recovery of cardiac functions, and the less production of oxygen-derived free radicals. Conclusion: Adult rat cardiac myocytes could express EPOR, and EPO pretreatment produced protective effects on myocardium with H/R injury.展开更多
Objective An efficient extraction and separation method of resveratrol from a Chinese herb giant knotweed was developed and the protective effect of resveratrol on myocardium injury was investigated.Methods An orthogo...Objective An efficient extraction and separation method of resveratrol from a Chinese herb giant knotweed was developed and the protective effect of resveratrol on myocardium injury was investigated.Methods An orthogonal experiment was utilized to optimize the extraction conditions and the pure white crystal obtained utilizing the proposed method was used for the investigation of myocardium ischemic injury.Results Resveratrol was found to have many beneficial activities including the protective effect on the heart and the scavenging of free radical.Conclusion The protective effect of resveratrol on myocardium injury is related to the quenching of lipid peroxidation.展开更多
Objective：Myocardial ischemia/reperfusion（I/R） injury is the leading cause of death in the world. However, the details of the mechanism of its pathophysiology are still unknown. The present study was designed to in...Objective：Myocardial ischemia/reperfusion（I/R） injury is the leading cause of death in the world. However, the details of the mechanism of its pathophysiology are still unknown. The present study was designed to investigate the role of connexin 43（Cx43） in acute models of myocardial I/R injury. Methods： Male C57BL/6 mice were subjected to myocardial ischemia（45 min） followed by reperfusion（4 hrs） in vivo. The whole operation was monitored using a two-lead ECG. Hearts were harvested and the level of protein was assessed by western blot analysis. Haematoxylin and Eosin（HE） staining was used to detect the extent of neutrophil infiltration. The expression level of IL-6 was detected by ELISA. Results： A murine myocardial I/R injury model was constructed successfully. Phosphorylated Cx43 decreased 83. 45% while non-phosphorylated Cx43 increased 1.62- fold in the myocardium after I/R injury. Neutrophil infiltration and the expression of the inflammatory cytokine IL-6 increased in the myocardium following I/R. Conclusion： During myocardial I/R injury, cardiomyocyte Cx43 is dephosphorylated, and this may be associated with an inflammatory response.展开更多
Advances in magnetic resonance(MR) and computed tomography(CT) imaging have improved visualization of acute and scar infarct.Over the past decade,there have been and continues to be many significant technical advancem...Advances in magnetic resonance(MR) and computed tomography(CT) imaging have improved visualization of acute and scar infarct.Over the past decade,there have been and continues to be many significant technical advancements in cardiac MR and multi-detector computed tomography(MDCT) technologies.The strength of MR imaging relies on a variety of pulse sequences and the ability to noninvasively provide information on myocardial structure,function and perfusion in a single imaging session.The recent technical developments may also allow CT technologies to rise to the forefront for evaluating clinical ischemic heart disease.Components of reperfusion injury including myocardial edema,hemorrhage,calcium deposition and microvascular obstruction(MO) have been demonstrated using MR and CT technologies.MR imaging can be used serially and noninvasively in assessing acute and chronic consequences of reperfusion injury because there is no radiation exposure or administration of radioactive materials.MDCT is better suited for assessing coronary artery stenosis and as an alternative technique for as-sessing viability in patients where MR imaging is contraindicated.Changes in left ventricular(LV) volumes and function measured on cine MR are directly related to infarct size measured on delayed contrast enhanced images.Recent MR studies found that transmural infarct,MO and peri-infarct zone are excellent predictors of poor post-infarct recovery and mortality.Recent MR studies provided ample evidence that growth factor genes and stem cells delivered locally have beneficial effects on myocardial viability,perfusion and function.The significance of deposited calcium in acute infarct detected on MDCT requires further studies.Cardiac MR and MDCT imaging have the potential for assessing reperfusion injury components and manifestations.展开更多
Nitric oxide formation and cyclic GMP level in the myocardium were studied in the early stage after radiation, bum andcombined radiation-bum injuries in rats. Nitric oxide synthase (NOS) activity was measured in the c...Nitric oxide formation and cyclic GMP level in the myocardium were studied in the early stage after radiation, bum andcombined radiation-bum injuries in rats. Nitric oxide synthase (NOS) activity was measured in the cytosol of the left ventricularwall. In the controls, the cytosol was found to contain mainly Ca2+ -dependent NOS (cNOS) and a small amount of Ca2+ -inden-pendent NOS (iNOS). After burn and combined radiation-burn injuries, a marked increase of iNOS activity with a peak in the 8thhour postinjury was found but the myocardial cNOS activity declined obviously. Parallel to iNOS activity increase, there was a significant increase of myocardial production of NO and cGMP. The combined effcts of radiation and burn injuries on the rats weremore severe than those of burn injury alone. All the changes could be prevented by the administration of dexamethasone. No obvious changes were observed in the rats after radiation injury alone. Since the increase of cGMP level in the heart is associated withreduced contractility, it is possible that the increased production of NO stimulated by iNOS accounts at least partially, for the depression of myocardial contractility after bum and combined radiation burn injury.展开更多
The mechanism of reperfusion injury of ischemic myocardium is not clear yet, and there has not been effective therapeutic methods up to now. Recently, growing evidence shows that the myocardial ischemia-reperfusion in...The mechanism of reperfusion injury of ischemic myocardium is not clear yet, and there has not been effective therapeutic methods up to now. Recently, growing evidence shows that the myocardial ischemia-reperfusion injury is similar in pathologic character and展开更多
文摘Objective: To establish the rat model with myocardial hypoxia/reoxygenation (H/R) injury, and investigate the protective effect of EPO pretreatment on the myocardium. Methods: Sixty male adult Wistar rats were randomly divided into 3 groups: control group, H/R group, and EPO group, 20 in each group. The rats in EPO group accepted injection of 5 000 U/kg recombinant human erythropoietin (RHuEPO) through vein, and the other rats accepted the injection of the same volume of saline. Twenty-four hours after the injection, rats in the EPO and H/R groups were put into the hypoxia environment for 12 h and then returned to the normoxic environment for 2 h, and then the samples of blood and myocardium were collected. Serum myocardial enzyme activity, apoptosis, ultrastructure, myocardial MDA contents, EPO receptor (EPOR) expression in cardiac myocytes and cardiac functions were tested. Results: EPOR expression was positive in cardiac myocytes of adult rat according to the result of immunonistochemitry assaying. Compared to those in H/R group, rats in EPO group presented lighter injury of myocardial ultrastructure, the reduction of serum myocardial enzyme activity, inhibition of apoptosis, the better recovery of cardiac functions, and the less production of oxygen-derived free radicals. Conclusion: Adult rat cardiac myocytes could express EPOR, and EPO pretreatment produced protective effects on myocardium with H/R injury.
文摘Objective An efficient extraction and separation method of resveratrol from a Chinese herb giant knotweed was developed and the protective effect of resveratrol on myocardium injury was investigated.Methods An orthogonal experiment was utilized to optimize the extraction conditions and the pure white crystal obtained utilizing the proposed method was used for the investigation of myocardium ischemic injury.Results Resveratrol was found to have many beneficial activities including the protective effect on the heart and the scavenging of free radical.Conclusion The protective effect of resveratrol on myocardium injury is related to the quenching of lipid peroxidation.
基金supported by Jiangsu Provincial Science Founda-tion of China (BK2006229)
文摘Objective：Myocardial ischemia/reperfusion（I/R） injury is the leading cause of death in the world. However, the details of the mechanism of its pathophysiology are still unknown. The present study was designed to investigate the role of connexin 43（Cx43） in acute models of myocardial I/R injury. Methods： Male C57BL/6 mice were subjected to myocardial ischemia（45 min） followed by reperfusion（4 hrs） in vivo. The whole operation was monitored using a two-lead ECG. Hearts were harvested and the level of protein was assessed by western blot analysis. Haematoxylin and Eosin（HE） staining was used to detect the extent of neutrophil infiltration. The expression level of IL-6 was detected by ELISA. Results： A murine myocardial I/R injury model was constructed successfully. Phosphorylated Cx43 decreased 83. 45% while non-phosphorylated Cx43 increased 1.62- fold in the myocardium after I/R injury. Neutrophil infiltration and the expression of the inflammatory cytokine IL-6 increased in the myocardium following I/R. Conclusion： During myocardial I/R injury, cardiomyocyte Cx43 is dephosphorylated, and this may be associated with an inflammatory response.
文摘Advances in magnetic resonance(MR) and computed tomography(CT) imaging have improved visualization of acute and scar infarct.Over the past decade,there have been and continues to be many significant technical advancements in cardiac MR and multi-detector computed tomography(MDCT) technologies.The strength of MR imaging relies on a variety of pulse sequences and the ability to noninvasively provide information on myocardial structure,function and perfusion in a single imaging session.The recent technical developments may also allow CT technologies to rise to the forefront for evaluating clinical ischemic heart disease.Components of reperfusion injury including myocardial edema,hemorrhage,calcium deposition and microvascular obstruction(MO) have been demonstrated using MR and CT technologies.MR imaging can be used serially and noninvasively in assessing acute and chronic consequences of reperfusion injury because there is no radiation exposure or administration of radioactive materials.MDCT is better suited for assessing coronary artery stenosis and as an alternative technique for as-sessing viability in patients where MR imaging is contraindicated.Changes in left ventricular(LV) volumes and function measured on cine MR are directly related to infarct size measured on delayed contrast enhanced images.Recent MR studies found that transmural infarct,MO and peri-infarct zone are excellent predictors of poor post-infarct recovery and mortality.Recent MR studies provided ample evidence that growth factor genes and stem cells delivered locally have beneficial effects on myocardial viability,perfusion and function.The significance of deposited calcium in acute infarct detected on MDCT requires further studies.Cardiac MR and MDCT imaging have the potential for assessing reperfusion injury components and manifestations.
文摘Nitric oxide formation and cyclic GMP level in the myocardium were studied in the early stage after radiation, bum andcombined radiation-bum injuries in rats. Nitric oxide synthase (NOS) activity was measured in the cytosol of the left ventricularwall. In the controls, the cytosol was found to contain mainly Ca2+ -dependent NOS (cNOS) and a small amount of Ca2+ -inden-pendent NOS (iNOS). After burn and combined radiation-burn injuries, a marked increase of iNOS activity with a peak in the 8thhour postinjury was found but the myocardial cNOS activity declined obviously. Parallel to iNOS activity increase, there was a significant increase of myocardial production of NO and cGMP. The combined effcts of radiation and burn injuries on the rats weremore severe than those of burn injury alone. All the changes could be prevented by the administration of dexamethasone. No obvious changes were observed in the rats after radiation injury alone. Since the increase of cGMP level in the heart is associated withreduced contractility, it is possible that the increased production of NO stimulated by iNOS accounts at least partially, for the depression of myocardial contractility after bum and combined radiation burn injury.
文摘The mechanism of reperfusion injury of ischemic myocardium is not clear yet, and there has not been effective therapeutic methods up to now. Recently, growing evidence shows that the myocardial ischemia-reperfusion injury is similar in pathologic character and
