Ischemic preconditioning or postconditioning has been shown to have neuroprotective effect on cerebral ischemia, but it has not been studied in peripheral nerve injury. In this study, a rat model of sciatic nerve tran...Ischemic preconditioning or postconditioning has been shown to have neuroprotective effect on cerebral ischemia, but it has not been studied in peripheral nerve injury. In this study, a rat model of sciatic nerve transection was established, and subjected to three cycles of ischemia for 10 minutes ＋ reperfusion for 10 minutes, once a day. After ischemic postconditioning, serum insulin-like growth factor 1 expression increased; sciatic nerve Schwann cell myelination increased; sensory function and motor function were restored. These findings indicate that ischemic postconditioning can effectively protect injured sciatic nerve. The protective effect is possibly associated with upregulation of insulin-like growth factor 1.展开更多
Objective： To investigate the effect of ischemic postconditioning （1PO） on acute lung ischemia-reperfusion （I/R） injury and the protein expression of haeme oxygenase-1 （HO-1）, a cytoprotective defense against o...Objective： To investigate the effect of ischemic postconditioning （1PO） on acute lung ischemia-reperfusion （I/R） injury and the protein expression of haeme oxygenase-1 （HO-1）, a cytoprotective defense against oxidative injury. Methods： After being anesthetized with chloralhydrate, forty-eight healthy SD rats were randomly divided into 6 groups （8 in each）： sham operation group （S group）; I/R group： left lung hilum was clamped for 40 minutes followed by 105 minutes of reperfusion; IPO group： left lung hilum was clamped for40 minutes and postconditioned by 3 cycles of 30 seconds of reperfusion and 30 seconds of reocclusion; Heroin （HM）＋ I/R group： heroin, an inducer of HO-1 was injected intraperitoneally at 40 μmol·kg^-1·day^-1 for two consecutive days prior to 40 minutes clamping of left lung hilum; ZnPPIX＋IPO group： zinc protoporphyrin IX, an inhibitor of HO-1 was injected intraperitoneally at 20 mg·kg^-1 24 hours prior to 40 minutes clamping of left lung hilum; and HM＋S group： HM was administered as in the HM＋I/R group without inducing lung I/R. Arterial partial pressure of oxygen （PaO2） and malondialdehyde （MDA） content in serum were assessed. The left lung was removed for determination of wet/dry lung weight ratio and expression of HO-1 protein by immuno-histochemical technique and for light microscopic examination. Results： The PaO2 was significantly lower in all the experimental groups compared with sham group （90 roan Hg ±11 mmHg）. However, the values of PaO2in IPO （81 mm Hg±7 mm Hg） and HM＋I/R （80 mm Hg±9 mm Hg） were higher than that in I/R （63 mm Hg±9 mm Hg） and ZnPPIX＋IPO （65 mm Hg±8 mm Hg） groups （P〈0.01）. The protein expression of HO- 1 in lung tissue was significantly increased in I/R group compared with S group （P〈0.01）. While the HO-1 protein expression was higher in IPO and HM＋I/R groups as compared with I/R group （P〈0.05, P〈0.01 ）. The lung wet/ dry （W/D） weight ratio and MDA content in serum were significantly increased in I/R group as compared with S or HM＋S groups （P〈0.01）, accompanied by severe lung tissue histological damage, which was attenuated either by IPO or by HM pretreatment （P〈0.01, IPO or HM＋I/R vs. I/R）. The protective effect of IPO was abolished by ZnPPIX. Conclusion： Ischemic postconditioning can attenuate the lung ischemia-reperfusion injury through upregulating the protein expression of HO-I that leads to reduced postischemic oxidative damage.展开更多
Objective： To explore the synergistic protection of Danhong Injection （丹红注射液,DHI） and ischemic postconditioning on myocardial reperfusion injury in minipigs.Methods： Acute myocardial infarction model was made...Objective： To explore the synergistic protection of Danhong Injection （丹红注射液,DHI） and ischemic postconditioning on myocardial reperfusion injury in minipigs.Methods： Acute myocardial infarction model was made by balloon occlusion in left anterior descending coronary artery （LAD） of minipigs,and then postconditioning was simulated through inflation/deflation of the angioplasty balloon.Minipigs were divided into four groups： the sham operation group （SH group）,the ischemia/reperfusion group （I/R group）,the ischemic postconditioning group （POC group） and DHI combined with ischemic postconditioning group （PAD group,DHI 20 mL through ear vein）,six in each group.After 24-h continuous observation,myocardial infarction size was assessed by triphenyltetrazolium staining （TTC）.Morphological changes of ischemic myocardium were observed by light microscopy,and cardiomyocyte ultrastructure was studied with electron microscopy.The superoxide dismutase （SOD） and malondialdehyde （MDA） activity in heart homogenates were measured by a biochemical method.Results： The myocardial infarction size was smaller in the POC group than in the I/R group （0.26±0.02 vs.0.37±0.09,P〈0.05）,and the PAD group （0.14±0.08） displayed a significantly reduced infarction size relative to the I/R group （P〈0.01） and POC group （P〈0.05）.The damage of myocardial tissue was severe in the I/R group shown by light and electron microscopy： myocardial fibers disorder,sarcoplasmic dissolution,myofilament fracture,mitochondria swelling and even vacuolization formation and a large number of inflammatory cell infiltrations.Compared with the I/R group,reduction of reperfusion injury in the PAD group included more orderly arranged myocardial fibers,less infiltration of inflammatory cells and maintenance of mitochondrial integrity.Compared with the I/R group,the damage of myocardial tissue in the POC group was improved,but not as significant as that in the PAD group.SOD levels in the POC group and the PAD group were significantly higher than those in the I/R group （96.96±13.43,112.25±22.75 vs.76.32±10.63,P〈0.05）,and MDA was significantly lower in the POC group and the PAD group compared to the I/R group （1.27±0.19,1.09±0.21 vs.1.47±0.16,P〈0.05）.Conclusion： DHI and ischemic postconditioning show a synergistic cardioprotection on myocardial reperfusion injury in minipigs.展开更多
BACKGROUND: Ischemia-reperfusion injury occurs when ischemic tissues or organs suffer from further functional and structural damage when their blood supply recovers. This study aimed to contrast the protective effects...BACKGROUND: Ischemia-reperfusion injury occurs when ischemic tissues or organs suffer from further functional and structural damage when their blood supply recovers. This study aimed to contrast the protective effects of ischemic preconditioning and ischemic postconditioning in hepatic ischemia-reperfusion injury in rats. METHODS: Thirty-two healthy male Wistar rats were randomly divided into four groups: sham-operated (SO), ischemia-reperfusion (IR), ischemic preconditioning (I-pre), and ischemic postconditioning (I-post). Blood samples and hepatic tissue were taken from all groups after the experiments. RESULTS: There were significant differences between the IR, I-pre and I-post groups in alanine aminotransferase and aspartate aminotransferase levels, NF-kappa B p65 expression, apoptosis index and superoxide dismutase activity in hepatic tissue. There were no significant differences between the I-pre and I-post groups. CONCLUSIONS: Ischemic postconditioning and ischemic preconditioning reduce hepatic ischemia-reperfusion injury, but in clinical practice the former is a more appropriate choice.展开更多
Background When patients suffering with ST-segment elevation myocardial infarction(STEMI) undergo an percutaneous coronary intervention(PCI) and open the infarct-related coronary artery(IRCA), a myocardial ischemia re...Background When patients suffering with ST-segment elevation myocardial infarction(STEMI) undergo an percutaneous coronary intervention(PCI) and open the infarct-related coronary artery(IRCA), a myocardial ischemia reperfusion injury(MIRI) will occur. This leads to severe complications, such as an enlarged myocardial infarction area, reperfusion arrhythmia, and heart failure. Finding ways to mitigate the effects of MIRIs is therefore important. Our study aims to observe the effect and significance of the gradual ischemic postconditioning(IPOC)treatment on MIRI and autonomic nerves system(ANS) in patients with STEMI during PCIs. Methods We took the 121 patients diagnosed with STEMI that had been hospitalized in the cardiology department of our hospital from March 2019 to September 2020, and divided them into a control group(60 cases) and treatment group(61 cases). The control group received conventional PCI treatment, and the treatment group received gradual IPOC treatment. Results The gradual IPOC group was shown to achieve significantly better results than the control group(P<0.01) in the following: reduction of the incidence rate of arrhythmia cases during PCI, increase in proportion of ST-segment resolution at 24 hours after PCI, suppression of the postoperative overexcitement of the sympathetic and vagus nerve systems, recovery of the cardiac autonomic nerve function, reduction of c Tn T, NT-pro BNP and hs-CRP concentrations, and improvement of LVEF value. Conclusion During emergency PCIs for patients with STEMI, the operation of an gradual IPOC can lessen the myocardial infarction area, reduce inflammation, improve heart function, reduce reperfusion arrhythmia, and promote the recovery of cardiac autonomic nerve function, thereby reduce MIRI and benefitting patients.展开更多
Background It has found that ischemic postconditioning （IPO） might decrease pulmonary ischemia/reperfusion （I/ R） injury,which is one of the main reasons of lung injury caused by cardiopulmonary bypass （CPB）.It ...Background It has found that ischemic postconditioning （IPO） might decrease pulmonary ischemia/reperfusion （I/ R） injury,which is one of the main reasons of lung injury caused by cardiopulmonary bypass （CPB）.It was found that aquaporins （AQPs） play a role in the maintenance of fluid homeostasis.But it is still unclear whether IPO influences the expression of aquaporin-1 （AQP1）.This study was designed to investigate whether IPO can reduce CPB-related lung injury and affect the expression of AQP1 of lungs.Methods Twelve healthy dogs were divided into control group （C group） and ischemia postconditioning group （IPO group）.CPB procedures were implemented.Ten minutes later,the left pulmonary artery was separated and blocked.Postconditioning consisted of two cycles of 5-minute pulmonary artery reperfusion/5-minute reocclusion starting at the beginning of reperfusion.The 2×4 cm tissues of both sides of pulmonary apex,superior,middle and inferior lobe were taken before CPB （T1）,before occlusion and reopening of left pulmonary artery （T2,T3）,and 2 hours after CPB （T4）.Samples were used to evaluate lung injury degrees and to detect the expression of AQP1.At T1 and T4,blood was collected from femoral artery to calculate pulmonary function.Results At T4,each pulmonary function showed significant deterioration compared with T1.Lung injury could be found at the onset of CPB.However,the expression of AQP1 decreased and wet to dry weight ratio （W/D） increased after T2.In the left lung of C group,the worst pulmonary function and structures were detected.The slightest changes were discovered in the right lung of C group.A close relationship between W/D and lung injury score was found.The lung injury score was negatively related with the expression of AQP1.It was found that the expression of AQP1 was negatively connected with W/D.Conclusions In dog CPB models,lung injury induced by CPB was related with down regulated expression of AQP1.AQP1 is believed to be involved in the mechanisms of lung ischemia/reperfusion （I/R） injury caused by CPB.IPO increases the expression of AQP1,provides a protective effect on lung suffering from CPB,and alleviates CPB-related lung injury.展开更多
Objective： To study the protective effect of ischenlic preconditioning （I-pre） and ischemic postconditioning （I- post） against ischenlia/reperfusion （I/R） injury in rat＇ s liver. Methods： Using rat model of ...Objective： To study the protective effect of ischenlic preconditioning （I-pre） and ischemic postconditioning （I- post） against ischenlia/reperfusion （I/R） injury in rat＇ s liver. Methods： Using rat model of hepatic segmental I/R injury, rats were divided into 5 groups： Group A （sham group）, Group B （I/R injury）, Group C （I-pre group）, Group D （I-post group ） and Group E （combined treatment of I-pre and I-post ）. Serum alanine aminotransferase （ ALT ）, aspartate aminotransferase （ AST）, malondiaidehyde （ MDA ）, glutathione （ GSH ）, superoxide dismutase （ SOD ）, glutathione peroxidase （GSH-Px） and myeloperoxidase （MPO） in hepatic tissues were determined, respectively. In addition, 7 days＇survival of Groups B, C, D and E were evaluated. Results. Compared with Group B, Groups C, D and E exhibited significantly decreased ALT and AST release, minimized tissue injury, suppressed values of MDA and MPO, increased activities of SOD, GSH-Px and GSH （P〈0.05 ）, as well as improved animal survival. The differences among Groups C, D and E were not statistically significant. Conclusions： I-pre, I-post and combined therapy of I-pre and I-post have protective effect against hepatic I/R injury, which is correlated with its function of reducing the production of reactive oxygen species, maintaining the activities of antioxidant systems and suppressing neutrophils recruitment. No additive effect can be obtained in Group E.展开更多
基金supported by the 2016 Beijing Municipal Natural Science Foundation(CN),No.71520061Beijing Municipal Science and Technology Commission,China,No.Z161100000116080
文摘Ischemic preconditioning or postconditioning has been shown to have neuroprotective effect on cerebral ischemia, but it has not been studied in peripheral nerve injury. In this study, a rat model of sciatic nerve transection was established, and subjected to three cycles of ischemia for 10 minutes ＋ reperfusion for 10 minutes, once a day. After ischemic postconditioning, serum insulin-like growth factor 1 expression increased; sciatic nerve Schwann cell myelination increased; sensory function and motor function were restored. These findings indicate that ischemic postconditioning can effectively protect injured sciatic nerve. The protective effect is possibly associated with upregulation of insulin-like growth factor 1.
基金This project was supported by the National Natural Science Foundation of China （No.30672033）.
文摘Objective： To investigate the effect of ischemic postconditioning （1PO） on acute lung ischemia-reperfusion （I/R） injury and the protein expression of haeme oxygenase-1 （HO-1）, a cytoprotective defense against oxidative injury. Methods： After being anesthetized with chloralhydrate, forty-eight healthy SD rats were randomly divided into 6 groups （8 in each）： sham operation group （S group）; I/R group： left lung hilum was clamped for 40 minutes followed by 105 minutes of reperfusion; IPO group： left lung hilum was clamped for40 minutes and postconditioned by 3 cycles of 30 seconds of reperfusion and 30 seconds of reocclusion; Heroin （HM）＋ I/R group： heroin, an inducer of HO-1 was injected intraperitoneally at 40 μmol·kg^-1·day^-1 for two consecutive days prior to 40 minutes clamping of left lung hilum; ZnPPIX＋IPO group： zinc protoporphyrin IX, an inhibitor of HO-1 was injected intraperitoneally at 20 mg·kg^-1 24 hours prior to 40 minutes clamping of left lung hilum; and HM＋S group： HM was administered as in the HM＋I/R group without inducing lung I/R. Arterial partial pressure of oxygen （PaO2） and malondialdehyde （MDA） content in serum were assessed. The left lung was removed for determination of wet/dry lung weight ratio and expression of HO-1 protein by immuno-histochemical technique and for light microscopic examination. Results： The PaO2 was significantly lower in all the experimental groups compared with sham group （90 roan Hg ±11 mmHg）. However, the values of PaO2in IPO （81 mm Hg±7 mm Hg） and HM＋I/R （80 mm Hg±9 mm Hg） were higher than that in I/R （63 mm Hg±9 mm Hg） and ZnPPIX＋IPO （65 mm Hg±8 mm Hg） groups （P〈0.01）. The protein expression of HO- 1 in lung tissue was significantly increased in I/R group compared with S group （P〈0.01）. While the HO-1 protein expression was higher in IPO and HM＋I/R groups as compared with I/R group （P〈0.05, P〈0.01 ）. The lung wet/ dry （W/D） weight ratio and MDA content in serum were significantly increased in I/R group as compared with S or HM＋S groups （P〈0.01）, accompanied by severe lung tissue histological damage, which was attenuated either by IPO or by HM pretreatment （P〈0.01, IPO or HM＋I/R vs. I/R）. The protective effect of IPO was abolished by ZnPPIX. Conclusion： Ischemic postconditioning can attenuate the lung ischemia-reperfusion injury through upregulating the protein expression of HO-I that leads to reduced postischemic oxidative damage.
基金Supported by the National Natural Science Foundation Major Research Plan (No.30772868)
文摘Objective： To explore the synergistic protection of Danhong Injection （丹红注射液,DHI） and ischemic postconditioning on myocardial reperfusion injury in minipigs.Methods： Acute myocardial infarction model was made by balloon occlusion in left anterior descending coronary artery （LAD） of minipigs,and then postconditioning was simulated through inflation/deflation of the angioplasty balloon.Minipigs were divided into four groups： the sham operation group （SH group）,the ischemia/reperfusion group （I/R group）,the ischemic postconditioning group （POC group） and DHI combined with ischemic postconditioning group （PAD group,DHI 20 mL through ear vein）,six in each group.After 24-h continuous observation,myocardial infarction size was assessed by triphenyltetrazolium staining （TTC）.Morphological changes of ischemic myocardium were observed by light microscopy,and cardiomyocyte ultrastructure was studied with electron microscopy.The superoxide dismutase （SOD） and malondialdehyde （MDA） activity in heart homogenates were measured by a biochemical method.Results： The myocardial infarction size was smaller in the POC group than in the I/R group （0.26±0.02 vs.0.37±0.09,P〈0.05）,and the PAD group （0.14±0.08） displayed a significantly reduced infarction size relative to the I/R group （P〈0.01） and POC group （P〈0.05）.The damage of myocardial tissue was severe in the I/R group shown by light and electron microscopy： myocardial fibers disorder,sarcoplasmic dissolution,myofilament fracture,mitochondria swelling and even vacuolization formation and a large number of inflammatory cell infiltrations.Compared with the I/R group,reduction of reperfusion injury in the PAD group included more orderly arranged myocardial fibers,less infiltration of inflammatory cells and maintenance of mitochondrial integrity.Compared with the I/R group,the damage of myocardial tissue in the POC group was improved,but not as significant as that in the PAD group.SOD levels in the POC group and the PAD group were significantly higher than those in the I/R group （96.96±13.43,112.25±22.75 vs.76.32±10.63,P〈0.05）,and MDA was significantly lower in the POC group and the PAD group compared to the I/R group （1.27±0.19,1.09±0.21 vs.1.47±0.16,P〈0.05）.Conclusion： DHI and ischemic postconditioning show a synergistic cardioprotection on myocardial reperfusion injury in minipigs.
文摘BACKGROUND: Ischemia-reperfusion injury occurs when ischemic tissues or organs suffer from further functional and structural damage when their blood supply recovers. This study aimed to contrast the protective effects of ischemic preconditioning and ischemic postconditioning in hepatic ischemia-reperfusion injury in rats. METHODS: Thirty-two healthy male Wistar rats were randomly divided into four groups: sham-operated (SO), ischemia-reperfusion (IR), ischemic preconditioning (I-pre), and ischemic postconditioning (I-post). Blood samples and hepatic tissue were taken from all groups after the experiments. RESULTS: There were significant differences between the IR, I-pre and I-post groups in alanine aminotransferase and aspartate aminotransferase levels, NF-kappa B p65 expression, apoptosis index and superoxide dismutase activity in hepatic tissue. There were no significant differences between the I-pre and I-post groups. CONCLUSIONS: Ischemic postconditioning and ischemic preconditioning reduce hepatic ischemia-reperfusion injury, but in clinical practice the former is a more appropriate choice.
基金supported by Foundation Project of Qingdao Medical Research Guidance Plan (No.2020-WJZD095)。
文摘Background When patients suffering with ST-segment elevation myocardial infarction(STEMI) undergo an percutaneous coronary intervention(PCI) and open the infarct-related coronary artery(IRCA), a myocardial ischemia reperfusion injury(MIRI) will occur. This leads to severe complications, such as an enlarged myocardial infarction area, reperfusion arrhythmia, and heart failure. Finding ways to mitigate the effects of MIRIs is therefore important. Our study aims to observe the effect and significance of the gradual ischemic postconditioning(IPOC)treatment on MIRI and autonomic nerves system(ANS) in patients with STEMI during PCIs. Methods We took the 121 patients diagnosed with STEMI that had been hospitalized in the cardiology department of our hospital from March 2019 to September 2020, and divided them into a control group(60 cases) and treatment group(61 cases). The control group received conventional PCI treatment, and the treatment group received gradual IPOC treatment. Results The gradual IPOC group was shown to achieve significantly better results than the control group(P<0.01) in the following: reduction of the incidence rate of arrhythmia cases during PCI, increase in proportion of ST-segment resolution at 24 hours after PCI, suppression of the postoperative overexcitement of the sympathetic and vagus nerve systems, recovery of the cardiac autonomic nerve function, reduction of c Tn T, NT-pro BNP and hs-CRP concentrations, and improvement of LVEF value. Conclusion During emergency PCIs for patients with STEMI, the operation of an gradual IPOC can lessen the myocardial infarction area, reduce inflammation, improve heart function, reduce reperfusion arrhythmia, and promote the recovery of cardiac autonomic nerve function, thereby reduce MIRI and benefitting patients.
文摘Background It has found that ischemic postconditioning （IPO） might decrease pulmonary ischemia/reperfusion （I/ R） injury,which is one of the main reasons of lung injury caused by cardiopulmonary bypass （CPB）.It was found that aquaporins （AQPs） play a role in the maintenance of fluid homeostasis.But it is still unclear whether IPO influences the expression of aquaporin-1 （AQP1）.This study was designed to investigate whether IPO can reduce CPB-related lung injury and affect the expression of AQP1 of lungs.Methods Twelve healthy dogs were divided into control group （C group） and ischemia postconditioning group （IPO group）.CPB procedures were implemented.Ten minutes later,the left pulmonary artery was separated and blocked.Postconditioning consisted of two cycles of 5-minute pulmonary artery reperfusion/5-minute reocclusion starting at the beginning of reperfusion.The 2×4 cm tissues of both sides of pulmonary apex,superior,middle and inferior lobe were taken before CPB （T1）,before occlusion and reopening of left pulmonary artery （T2,T3）,and 2 hours after CPB （T4）.Samples were used to evaluate lung injury degrees and to detect the expression of AQP1.At T1 and T4,blood was collected from femoral artery to calculate pulmonary function.Results At T4,each pulmonary function showed significant deterioration compared with T1.Lung injury could be found at the onset of CPB.However,the expression of AQP1 decreased and wet to dry weight ratio （W/D） increased after T2.In the left lung of C group,the worst pulmonary function and structures were detected.The slightest changes were discovered in the right lung of C group.A close relationship between W/D and lung injury score was found.The lung injury score was negatively related with the expression of AQP1.It was found that the expression of AQP1 was negatively connected with W/D.Conclusions In dog CPB models,lung injury induced by CPB was related with down regulated expression of AQP1.AQP1 is believed to be involved in the mechanisms of lung ischemia/reperfusion （I/R） injury caused by CPB.IPO increases the expression of AQP1,provides a protective effect on lung suffering from CPB,and alleviates CPB-related lung injury.
文摘Objective： To study the protective effect of ischenlic preconditioning （I-pre） and ischemic postconditioning （I- post） against ischenlia/reperfusion （I/R） injury in rat＇ s liver. Methods： Using rat model of hepatic segmental I/R injury, rats were divided into 5 groups： Group A （sham group）, Group B （I/R injury）, Group C （I-pre group）, Group D （I-post group ） and Group E （combined treatment of I-pre and I-post ）. Serum alanine aminotransferase （ ALT ）, aspartate aminotransferase （ AST）, malondiaidehyde （ MDA ）, glutathione （ GSH ）, superoxide dismutase （ SOD ）, glutathione peroxidase （GSH-Px） and myeloperoxidase （MPO） in hepatic tissues were determined, respectively. In addition, 7 days＇survival of Groups B, C, D and E were evaluated. Results. Compared with Group B, Groups C, D and E exhibited significantly decreased ALT and AST release, minimized tissue injury, suppressed values of MDA and MPO, increased activities of SOD, GSH-Px and GSH （P〈0.05 ）, as well as improved animal survival. The differences among Groups C, D and E were not statistically significant. Conclusions： I-pre, I-post and combined therapy of I-pre and I-post have protective effect against hepatic I/R injury, which is correlated with its function of reducing the production of reactive oxygen species, maintaining the activities of antioxidant systems and suppressing neutrophils recruitment. No additive effect can be obtained in Group E.
