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Resumen Antecedentes: En los pacientes con infarto agudo de miocardio con elevación del segmento ST (IAMCEST), el acondicionamiento isquémico puede ayudar a limitar la remodelación ventricular. Objetivos: Investigar el efecto del posacondicionamiento isquémico remoto (PAIR) en la función del ventrículo izquierdo durante la intervención coronaria percutánea primaria (ICPP) en pacientes con IAMCEST. Material y métodos: Estudio de intervención pre y posprueba con un total de 60 pacientes con IAMCEST. Los pacientes fueron divididos en dos grupos: con y sin PAIR. Resultados: En el seguimiento de seis meses se observó una diferencia significativa en la fracción de eyección del ventrículo izquierdo en pacientes con ICPP, la cual fue mayor en el grupo con PAIR en comparación con el grupo sin PAIR: 1.0 (−1.0 a 4.3) versus −1.0 (−4.0 a 1.3), p = 0.033. En la medición de seis meses, el volumen sistólico final del ventrículo izquierdo en los pacientes sin PAIR fue mayor en comparación con el grupo homólogo: 79.3 ± 30.5 mL versus 64.4 ± 21.4 mL, p = 0.032. Conclusiones: PAIR muestra efectos favorables en la función ventricular izquierda y, por lo tanto, en el futuro podría ser una estrategia cardioprotectora potencial contra la lesión por isquemia-reperfusión en pacientes con IAMCEST.
Abstract Background: Ischemic conditioning may help patients with ST-segment elevation myocardial infarction (STEMI) to limit ventricular remodeling. Objectives: To investigate the effect of remote ischemic postconditioning (RIPC) on left ventricular function during primary percutaneous coronary intervention (PPCI) in patients with STEMI. Material and methods: Pre- and post-test intervention study with a total of 60 STEMI patients. Patients were divided in two groups: with and without RIPC. Results: At 6-month follow-up evaluation, a significant difference in left ventricular ejection fraction was observed in patients who underwent PPCI, which was higher in the group with RIPC in comparison with the group without RIPC: 1.0 (−1.0 to 4.3) vs. −1.0 (−4.0 to 1.3), p = 0.033. In addition, at 6-month measurement, left ventricular end-systolic volume in patients without RIPC: was higher in comparison with their counterparts: 79.3 ± 30.5 mL versus 64.4 ± 21.4 mL, p = 0.032. Conclusions: RIPC shows favorable effects on left ventricular function and, therefore, in the future, it could be a potential cardioprotective strategy against ischemia-reperfusion injury in STEMI patients.
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ABSTRACT Objective: To explore the effect of ischemic postconditioning on myocardial ischemia-reperfusion-induced acute lung injury (ALI). Methods: Forty adult male C57BL/6 mice were randomly divided into sham operation group (SO group), myocardial ischemia-reperfusion group (IR group), ischemic preconditioning group (IPRE group) and ischemic postconditioning group (IPOST group) (10 mice in each group). Anterior descending coronary artery was blocked for 60 min and then reperfused for 15 min to induce myocardial IR. For the IPRE group, 3 consecutive cycles of 5 min of occlusion and 5 minutes of reperfusion of the coronary arteries were performed before ischemia. For the IPOST group, 3 consecutive cycles of 5 min reperfusion and 5 minutes of occlusion of the coronary arteries were performed before reperfusion. Pathological changes of lung tissue, lung wet-to-dry (W/D) weight ratio, inflammatory factors, oxidative stress indicators, apoptosis of lung cells and endoplasmic reticulum stress (ERS) protein were used to evaluate lung injury. Results: After myocardial IR, lung injury worsened significantly, manifested by alveolar congestion, hemorrhage, structural destruction of alveolar septal thickening, and interstitial neutrophil infiltration. In addition, lung W/D ratio was increased, plasma inflammatory factors, including interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-17A, were increased, malondialdehyde (MDA) activity of lung tissue was increased, and superoxide dismutase (SOD) activity was decreased after myocardial IR. It was accompanied by the increased protein expression levels of ERS-related protein glucose regulatory protein 78 (GRP78), CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP), and caspase-12, and the increased apoptotic indices of lung tissues. Conclusion: IPOST can effectively improve myocardial IR-induced ALI by inhibiting ERS-induced apoptosis of alveolar epithelial cells.
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Purpose: Acute mesenteric ischemia (AMI) is a condition in pediatric surgery that ranges from intestine necrosis to death. Ischemic postconditioning (IPoC) methods were developed to reduce the damage caused by revascularization. This study aimed to evaluate the efficacy of these methods in an experimental weaning rat model. Methods: Thirty-two 21-day-old Wistar rats were allocated into four groups according to the surgical procedure performed: control, ischemia-reperfusion injury (IRI), local (LIPoC) and remote IPoC (RIPoC). At euthanasia, fragments of the intestine, liver, lungs, and kidneys were submitted to histological, histomorphometric, and molecular analyses. Results: In the duodenum, intestines, and kidneys histological alterations promoted by IRI were reversed by remote postconditioning method. In the distal ileum, the histomorphometric alterations could be reversed by the postconditioning methods with more evident effects promoted by the remote method. The molecular analysis found that the levels of expression of Bax (proapoptotic) and Bcl-XL (antiapoptotic) genes in the intestine were increased by IRI. These alterations were equally reversed by the postconditioning methods, with more evident effects of the remote method. Conclusions: IPoC methods positively reduced the damage caused by IRI in weaning rats.
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Animals , Rats , Reperfusion Injury , Rats, Wistar , Ischemic Postconditioning/veterinary , Mesenteric Ischemia/veterinary , AntioxidantsABSTRACT
Objective:To evaluate the role of silent information regulator-1 (SIRT1)/nucleotide-binding domain (NOD)-like receptor protein-3 (NLRP3) signaling pathway in sevoflurane postconditioning-induced attenuation of oxygen-glucose deprivation and restoration (OGD/R) injury in mouse hippocampal neuronal cell line (HT22) cells.Methods:The HT22 cells were seeded in a culture plate (96-well plate, 100 μl/well; 6-well plate, 2 ml/well) at the density of 5×10 4 cells/ml or in a culture dish (6 cm in diameter) and then divided into 4 groups ( n=24 each) using a random number table method: control group (Control group), OGD/R group, sevoflurane postconditioning group (SPC group), and SIRT1 small interfering RNA group (si-SIRT 1 group). In Control group, cells were cultured at 37 ℃ in normal culture atmosphere. In OGD/R group, the culture medium was replaced with glucose-free serum-free culture medium, and cells were exposed to 95% N 2+ 5% CO 2 for 4 h in an incubator at 37 ℃, and then the glucose-free serum-free culture medium was replaced with the primary culture medium, and cells were cultured for 24 h at 37 ℃ in normal culture atmosphere. In SPC group, the glucose-free serum-free culture medium was replaced with the primary cell culture medium after 4-h oxygen and glucose deprivation, the cells were put into the hypoxia incubator chamber which was filled with 2% sevoflurane immediately after start of reoxygenation, then the chamber was placed in an incubator and the cells were cultured for 1 h at 37 ℃ in normal culture atmosphere, and finally the cells were removed from the chamber and cultured for 23 h at 37 ℃ in normal culture atmosphere. In si-SIRT1 group, SIRT1 small interfering RNA 150 pmol was added at 24 h before surgery, cells were then incubated, and the other procedures were the same as those previously described in group SPC. The cell survival rate was determined using MTT assay. TUNEL assay was used to detect cell apoptosis, and the apoptosis rate was calculated. The expression of SIRT1, NLRP3, IL-1β and IL-18 mRNA was determined using polymerase chain reaction. The expression of SIRT1, NLRP3, interleukin-1beta (IL-1β) and IL-18 was detected using Western blot. Results:Compared with Control group, the cell survival rate was significantly decreased, the apoptosis rate was increased, the expression of SIRT1 protein and mRNA was down-regulated, and the expression of NLRP3, IL-1β and IL-18 protein and mRNA was up-regulated in OGD/R group ( P<0.05). Compared with OGD/R group, the cell survival rate was significantly increased, the apoptosis rate was decreased, the expression of SIRT1 protein and mRNA was up-regulated, and the expression of NLRP3, IL-1β and IL-18 protein and mRNA was down-regulated in SPC group ( P<0.05). Compared with SPC group, the cell survival rate was significantly decreased, the apoptosis rate was increased, the expression of SIRT1 protein and mRNA was down-regulated, and the expression of NLRP3, IL-1β and IL-18 protein and mRNA was up-regulated in si-SIRT1 group ( P<0.05). Conclusions:Activation of SIRT1-NLRP3 signaling pathway is involved in sevoflurane postconditioning-induced attenuation of OGD/R injury in HT22 cells.
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Objective:To evaluate the role of succinate dehydrogenase (SDH) in hypoxic postconditioning (HPC)-induced reduction of hypoxia-reoxygenation (H/R) injury in myocardial cells of rats and the relationship with mitochondrial ATP-sensitive potassium channels (mito-K ATP). Methods:Myocardial cells isolated from adult male Sprague-Dawley rats were cultured for 48 h and then divided into 7 groups ( n=24 each) using a random number table method: blank control group (Nor group), H/R group, SDHA-siRNA adenovirus+ H/R group (siRNA+ H/R group), HPC group, SDHA-siRNA adenovirus+ HPC group (siRNA+ HPC group), 5-HD+ HPC group, and SDHA-siRNA adenovirus+ 5-HD+ HPC group (siRNA+ 5-HD+ HPC group). Nor group was continuously cultured for 195 min under normoxic conditions. The H/R injury model was prepared by exposing the cells to hypoxia for 45 min in 5% CO 2 + 1% O 2 + 94% N 2, followed by reoxygenation for 150 min. The HPC method involved three cycles of 5 min reoxygenation/5 min hypoxia at the end of 45 min ischemia before 120 min reoxygenation. The mito-K ATP blocker 5-HD administration method involved adding 5-HD at a final concentration of 100 μmol/L at 30 min of hypoxia. The myocardial cells in each siRNA group were successfully transfected with SDHA-siRNA adenovirus to silence SDHA expression. The cell viability, calcium ion level, SDH activity, ATP content, degree of mitochondrial permeability transition pore (mPTP) opening, and mitochondrial membrane potential (MMP) were measured at the end of reoxygenation. Results:Compared with Nor group, the cell viability, ATP content and MMP were significantly decreased, and the degree of mPTP opening, level of calcium ion and activity of SDH were increased in H/R group ( P<0.05). Compared with H/R group, the cell viability, ATP content and MMP were significantly increased, and the degree of mPTP opening, calcium ion level and SDH activity were decreased in siRNA+ H/R group and HPC group ( P<0.05). Compared with HPC group, the cell viability, ATP content and MMP were significantly decreased, and the degree of mPTP opening, calcium ion level and SDH activity were increased in 5-HD+ HPC group ( P<0.05), and the cell viability, ATP content and MMP were significantly increased, and the degree of mPTP opening, calcium ion level and SDH activity were decreased in siRNA+ HPC group ( P<0.05). Compared with siRNA+ HPC group, the cell viability, ATP content and MMP were significantly decreased, the opening degree of mPTP and calcium ion level were increased ( P<0.05), and no significant change was found in the SDH activity in siRNA+ 5-HD+ HPC group ( P>0.05). Compared with 5-HD+ HPC group, the SDH activity was significantly decreased, and no significant change was found in the other parameters in siRNA+ 5-HD+ HPC group ( P>0.05). Conclusions:HPC alleviates H/R injury probably by reducing SDH activity and opening mito-K ATP in myocardial cells of rats.
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Abstract Ischemic postconditioning (IPTC) brings cardioprotection endogenously, Atrial natriuretic peptide (ANP) produces the same effect. It happens due to down expression of endothelial nitric oxide synthase (eNOS). Thus, experimental protocol associating IPTC has been formulated to find the role of ANP in the cardioprotection of heart in OVX rats. For this experiment, heart was isolated from OVX rat and held tightly on Langendorff's apparatus in a manner that ischemia of 30 min and reperfusion of 120 min were also given. Simultaneously, IPTC with four cycles of 5 min ischemia and 5 min reperfusion of each was applied. Parameters like size of myocardial infarct, levels of lactate dehydrogenase (LDH) and release of creatine kinase- MB (CK-MB) in coronary effluent were noted after each stage of experiment for ensuring the extent of myocardial injury. Some significant changes were also seen in the histopathology of cardiovascular tissues. The cardio-protection has been made by four cycles of IPTC. It was confirmed by decline in the size of myocardial infarct. It diminishes the release of LDH and CK-MB in heart of OVX rat. Thus, IPTC induces cardio-protection in the isolated heart from OVX rat. Perfusion of ANP associating with IPTC favors the cardioprotection which is further confirmed by rise in the NO release and heart rate. The level of myocardial damage changes using IPTC, IPTC+OVX, IPTC+OVX+ANP, IPTC+ OVX+ANP+L-NAME and other groups were observed significantly and were found to be less than those in I/R control group. Thus, it is recommended that ANP involving IPTC restores attenuated cardio-protection in OVX rat heart. Therefore, Post-conditioning is useful in various clinical aspects.
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Objective:To evaluate the role of glucagon-like peptide-1 receptor (GLP-1R) signaling pathway in sevoflurane postconditioning-induced attenuation of myocardial ischemia-reperfusion (I/R) injury in rats.Methods:Eighty SPF healthy adult male Sprague-Dawley rats, aged 8-10 weeks, weighing 300-340 g, were divided into 4 groups ( n=20 each) by a random number table method: sham operation group (group S), myocardial I/R group (group I/R), myocardial I/R plus sevoflurane postconditioning group (group ISP), and myocardial I/R plus sevoflurane postconditioning plus GLP-1R antagonist group (group ISPE). The myocardial I/R injury model was developed by ligating the left anterior descending branch of the coronary artery for 40 min followed by 2-h reperfusion in anesthetized rats.In group ISP, the rats inhaled 2.4% sevoflurane for 15 min starting from the beginning of reperfusion.In group ISPE, GLP-1R antagonist Exendin9-39 50 μg/kg (in 1 ml 0.9% normal saline) was intraperitoneally injected once a day from 28 days before development of the model, the last intraperitoneal injection was completed at 40 min before inhalation of sevoflurane, and the other treatments were the same as those previously described in group ISP.Blood samples from the abdominal aorta were collected immediately after reperfusion to determine the serum levels of creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH). Then the rats were sacrificed, and the hearts were obtained for microscopic examination of the histopathological changes of myocardial tissues (by HE staining) and the ultrastructure of cardiomyocytes (with a transmission electron microscope) for determination of the myocardial infarct size (TTC staining), expression of GLP-1R in myocardium (by immunohistochemical staining), expression of GLP-1R, cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), cAMP response element-binding protein (CREB), phospho-CREB (p-CREB), B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated x protein (Bax) in myocardium (by Western blot). The ratios of p-CREB/CREB and Bcl-2/Bax were calculated. Results:Compared with group S, the serum levels of CK-MB and LDH and percentage of myocardial infarct size were significantly increased, the expression of GLP-1R was up-regulated, the expression of cAMP and PKA was down-regulated, and the p-CREB/CREB ratio and Bcl-2/Bax ratio were decreased in group I/R ( P<0.05). Compared with group I/R, the serum levels of CK-MB and LDH and percentage of myocardial infarct size were significantly decreased, the expression of GLP-1R, cAMP and PKA was up-regulated, and p-CREB/CREB ratio and Bcl-2/Bax ratio were increased in group ISP ( P<0.05). Compared with group ISP, the serum levels of CK-MB and LDH and percentage of myocardial infarct size were significantly increased, the expression of GLP-1R, cAMP and PKA was down-regulated, and the p-CREB/CREB ratio and Bcl-2/Bax ratio were decreased in group ISPE ( P<0.05). Conclusions:Sevoflurane postconditioning can attenuate myocardial I/R injury by activation of GLP-1R signal pathway and inhibition of cardiomyocyte apoptosis in rats.
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ABSTRACT Purpose To investigate the effect of ischemic postconditioning (IPostC) on skeletal muscle and its optimal protocol. Methods This article is about an animal study of rat model of crush syndrome. Sixty rats were randomized into nine different IPostC intervention groups and a control group. The anesthetized rats were subjected to unilateral hindlimb 3-kg compression with a compression device for 6 h, followed by nine different IPostC intervention protocols. Results Serum levels of creatine kinase (CK) at 3 h post-crush became 2.3-3.9 times among all 10 groups after crush. At 72 h post-crush, serum CK level was reduced to 0.28-0.53 time in all intervention groups. The creatinine (CREA) level in the control group was elevated to 3.11 times at 3 h post-crush and reduced to1.77 time at 72 h post-crush. The potassium (K+) level in the control group was elevated to 1.65 and 1.41 time at 3 and 72 h post-crush, respectively. Conclusions Our IPostC intervention protocols can effectively protect rats from crush-induced elevation of serum CK, CREA, and K+ levels. The timing of IPostC intervention should be as early as possible, to ensure the protective effect.
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Animals , Rats , Crush Syndrome/therapy , Ischemic Postconditioning , Rats, Sprague-Dawley , Muscle, Skeletal , Creatine KinaseABSTRACT
ABSTRACT Purpose To clarify the best protocol for performing remote ischemic conditioning and to minimize the consequences of ischemia and reperfusion syndrome in brain, the present study aimed to evaluate different time protocols and the relation of the organs and the antioxidant effects of this technique. Methods The rat's left femoral artery was clamped with a microvascular clamp in times that ranged from 1 to 5 minutes, according to the corresponding group. After the cycles of remote ischemic conditioning and a reperfusion of 20 minutes, the brain and the left gastrocnemius were collected. The samples were used to measure glutathione peroxidase, glutathione reductase and catalase levels. Results In the gastrocnemius, the 4-minute protocol increased the catalase concentration compared to the 1-minute protocol, but the latter increased both glutathione peroxidase and glutathione reductase compared to the former. On the other hand, the brain demonstrated higher catalase and glutathione peroxidase in 5-minute group, and the 3-minute group reached higher values of glutathione reductase. Conclusions Remote ischemic conditioning increases brain antioxidant capacity in a time-dependent way, while muscle presents higher protection on 1-minute cycles and tends to decrease its defence with longer cycles of intermittent occlusions of the femoral artery.
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Animals , Rats , Reperfusion Injury/prevention & control , Antioxidants , Brain , Glutathione Peroxidase , IschemiaABSTRACT
ABSTRACT Purpose: The aim of this study is to compare the hepatic protective effect of both remote and local postconditioning (POS). Methods: Twenty-eight Wistar rats were assigned into four groups: sham group(SHAM), ischemia-reperfusion group (IR), local ischemic POS group (lPOS) and remote ischemic POS group (rPOS). Animals were subjected to liver ischemia for 30 min. Local ischemic POS group consisted of four cycles of 5 min liver ischemia, followed by 5 min reperfusion (40 min). Remote ischemic POS group consisted of four cycles of 5 min hind limb ischemia, followed by 5 min hind limb perfusion after the main liver ischemia period. After 190 minutes median and left liver lobes were harvested for biochemical and histopathology analysis. Results: All the conditioning techniques were able to increase the level of bothglutathione reductase and peroxidase, showing higher values in the rPOS group when compared to the lPOS. Also, thiobarbituric acid reactive substances were higher in all intervention groups when compared to SHAM, but rPOS had the lower rates of increase, showing the best result. The histopathology analysis showed that all groups had worst injury levels than SHAM, but rPOS had lower degrees of damage when compared to the lPOS, although it was not statistically significant. Conclusion: Remote postconditioning is a promising technique to reduce liver ischemia-reperfusion injury, once it increased antioxidants substances and reduced the damage.
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Animals , Rats , Reperfusion Injury/prevention & control , Ischemic Preconditioning , Ischemic Postconditioning , Rats, WistarABSTRACT
Objective:To evaluate the relationship between phosphorylation of glycogen synthase kinase-3β (GSK-3β) and high glucose-caused abolition of cardioprotection induced by sevoflurane postconditioning.Methods:H9c2 cells were incubated in normal glucose (5.56 mmol/L) DMEM culture medium or high glucose (33 mmol/L) DMEM culture medium.The cells were divided into 8 groups ( n=24 each) using a random number table method: normal control group (group NC), normal glucose-cultured hypoxia/reoxygenation (H/R) group (group NH/R), normal glucose-cultured sevoflurane postconditioning group (group NS), normal glucose-cultured GSK-3β inhibitor SB216763 group (group NSB), high glucose-cultured group (group HC), high glucose-cultured H/R group (group HH/R), high glucose-cultured sevoflurane postconditioning group (group HS) and high glucose-cultured GSK-3β inhibitor SB216763 group (group HSB). The model of cardiomyocyte H/R was established by subjecting cardiomyocytes to 3 h of hypoxia followed by reoxygenation.Immediately after onset of reoxygenation, cardiomyocytes were exposed to 2.4% sevoflurane for 30 min in Ns and HS groups.Before the beginning of reoxygenation, GSK-3β inhibitor SB216763 was added to the culture medium with the final concentration of 10 μmol/L in NSB and HSB groups.At 3 h of reoxygenation, the apoptosis rate was determined by Anexin V-PI flow cytometry, the expression of GSK-3β and phosphorylated GSK-3β (p-GSK-3β) was detected by Western blot, superoxide dismutase (SOD) activity was measured using xanthineoxidase method, and lactic dehydrogenase (LDH) activity and malondialdehyde (MDA) content were determined by colorimetric assay. Results:Compared with group NC, apoptosis rate, LDH activity and MDA content were significantly increased, and SOD activity was decreased in group NH/R and group HC, expression of GSK-3β was up-regulated, and expression of p-GSK-3β was down-regulated in group NH/R, expression of p-GSK-3β was up-regulated in group NS, and expression of p-GSK-3β was down-regulated in group HC ( P<0.05). Compared with group NH/R, apoptosis rate, LDH activity and MDA content were significantly decreased, and SOD activity was increased in group NS and NSB groups, and expression of GSK-3β was down-regulated, and expression of p-GSK-3β was up-regulated in group NS ( P<0.05). Compared with group HC, apoptosis rate, LDH activity and MDA content were significantly increased, SOD activity was decreased, expression of GSK-3β was up-regulated, and expression of p-GSK-3β was down-regulated in group HH/R ( P<0.05). Compared with group HH/R, apoptosis rate, LDH activity and MDA content were significantly decreased, and SOD activity was increased in group HSB ( P<0.05). Conclusion:The mechanism by which high glucose abolishes cardioprotection induced by sevoflurane postconditioning is related to inhibiting phosphorylation of GSK-3β.
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Objective:To evaluate the relationship between the mitochondrial mechanism of diabetic mellitus-caused abolition of cardioprotection induced by ischemia postconditioning (IPO) and succinate dehydrogenase (SDH) in rats.Methods:Thirty-six SPF male non-diabetic Sprague-Dawley rats, aged 16-20 weeks, weighing about 300 g, were divided into 3 groups ( n=12 each) using a random number table method: sham operation group (ND+ Sham group), ischemia-reperfusion (I/R) group (ND+ I/R group) and IPO group (ND+ IPO group). Seventy-two rats with diabetes mellitus were divided into 6 groups ( n=12 each) using a random number table method: sham operation group (DM+ Sham group), I/R group (DM+ I/R group), DM+ IPO group, sham operation+ dimethyl malonate group (group DM+ Sham+ Dme), I/R+ dimethyl malonate group (group DM+ I/R + Dme) and IPO+ dimethyl malonate group (group DM+ IPO+ Dme). The model of cardiopulmonary bypass (CPB) was established, and the model of total I/R injury was induced by ligating the ascending aorta for 30 min followed by 60 min of reperfusion.The animals underwent 3 cycles of 30-s reperfusion followed by 30-s ischemia starting from the onset of reperfusion in each IPO group.In each Dme group, dimethyl malonate was infused through the tail vein at a rate of 4 mg· kg -1·min -1 for 40 min starting from the beginning of CPB.At the end of reperfusion, the myocardial tissues were taken for measurement of mitochondrial respiratory control ratio (RCR) (by the Lufthansa electrode method), mitochondrial membrane potential (MMP) (by the JC-1 method) and the opening of mitochondrial permeability transition pore (mPTP) (by absorptiometry) and for determination of the activity of reactive oxygen species (ROS) (with the fluorescent probe), succinate dehydrogenase (SDH) (using spectrophotometric method) and the contents of succinic acid and fumarate. Results:Compared with ND+ Sham group, the activities of SDH and ROS, opening of mPTP and content of fumarate were significantly increased, and MMP, RCR and succinic acid content were decreased in ND+ I/R ( P<0.05). Compared with group ND+ I/R, the activities of SDH and ROS, opening of mPTP and content of fumarate were significantly decreased, and MMP, RCR and succinic acid content were increased in ND+ IPO ( P<0.05). Compared with group DM+ Sham, the activities of SDH and ROS, opening of mPTP and content of fumarate were significantly increased, and MMP, RCR and succinic acid content were decreased in group DM+ I/R ( P<0.05). Compared with group DM+ I/R, no significant change was found in the parameters mentioned above in group DM+ IPO ( P>0.05). Compared with group DM+ IPO, the activities of SDH and ROS, opening of mPTP and content of fumarate were significantly decreased, and MMP, RCR and succinic acid content were increased in group DM+ IPO+ Dme ( P<0.05). Compared with group DM+ I/R+ Dme, the activities of SDH and ROS, opening of mPTP and content of fumarate were significantly decreased, and MMP, RCR and succinic acid content were increased in group DM+ IPO+ Dme ( P<0.05). Conclusion:The mitochondrial mechanism of diabetic mellitus-caused abolition of cardioprotection induced by IPO may be related to the enhancement of SDH activity in rats.
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Objective:To evaluate the effect of propofol postconditoning on retinoblastoma protein (Rb)-E2F1 signaling pathway in hippocampal neurons in a rat model of oxygen-glucose deprivation and restoration (OGD/R).Methods:Pregnant Wistar rats at 16-18 days of gestation were sacrificed, and the hippocampal neurons of fetal rats were obtained and primarily cultured for 7 days.The neurons were divided into 3 groups ( n=42 each) using a random number table method: control group (group C), OGD/R group (group O) and propofol postconditoning group (group P). In group O, the neurons were subjected to oxygen-glucose deprivation for 1 h, followed by restoration of oxygen-glucose.In group P, propofol (final concentration 1.2 μg/ml) was added immediately after restoration of oxygen and glucose, and the cells were cultured for 2 h and then the culture medium was replaced with plain culture medium.At 24 h of culture, the expression of p-Rb and E2F1 was determined by Western blot, and the cell cycle and apoposis rate were assessed by flow cytometry. Results:Compared with group C, the apoptosis rate was significantly increased, expression of p-Rb and E2F1 was up-regulated, the ratio of p-Rb nuclear/plasmosin protein and the proportion of neurons in G 0/G 1 phase were decreased, and the proportion of neurons in S and G 2/M phases was increased in O and P groups ( P<0.05). Compared with group O, the apoptosis rate was significantly decreased, expression of p-Rb and E2F1 was down-regulated, the ratio of p-Rb nuclear/plasmosin protein and the proportion of neurons in G 0/G 1 phase were increased, and the proportion of neurons in S and G 2/M phases was decreased in group P ( P<0.05). Conclusion:The mechanism by which propofol postconditioning decreases the apoptosis in hippocampal neurons is related to inhibiting Rb-E2F1 signaling pathway in a rat model of OGD/R.
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Recanalization therapy is the standard treatment for acute ischemic stroke. However, sometimes blood flow reperfusion not only fails to restore brain function, but also leads to further necrosis and apoptosis of neurons, thereby aggravating brain tissue damage and brain dysfunction of the patients, that is, reperfusion injury. Remote ischemic conditioning (RIC) is a simple, safe, convenient and easy method to protect brain tissue, improve cerebral blood flow and alleviate ischemia-reperfusion injury by giving multiple transient ischemic treatments to remote organs (usually limbs). This article reviews the application of RIC in the field of acute ischemic stroke in recent years.
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Abstract Purpose To investigate whether heat shock protein 90 (HSP90) is involved in complement regulation in ischemic postconditioning (IPC). Methods The left coronary artery of rats underwent 30 min of occlusion, followed by 120 min of reperfusion and treatment with IPC via 3 cycles of 30s reperfusion and 30s occlusion. The rats were injected intraperitoneally with 1 mg/kg HSP90 inhibitor geldanamycin (GA) after anesthesia. Eighty rats were randomly divided into four groups: sham, ischemia-reperfusion (I/R), IPC and IPC + GA. Myocardial infarct size, apoptosis index and the expression of HSP90, C3, C5a, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1β and c-Jun N-terminal kinase (JNK) were assessed. Results Compared with the I/R injury, the IPC treatment significantly reduced infarct size, release of troponin T, creatine kinase-MB, and lactate dehydrogenase, and cardiomyocyte apoptosis. These beneficial effects were accompanied by a decrease in TNF-α, IL-1β, C3, C5a and JNK expression levels. However, all these effects were abrogated by administration of the HSP90 inhibitor GA. Conclusion HSP90 exerts a profound effect on IPC cardioprotection, and may be linked to the inhibition of the complement system and JNK, ultimately attenuating I/R-induced myocardial injury and apoptosis.
Subject(s)
Animals , Rats , Complement System Proteins/metabolism , Myocardial Reperfusion Injury/metabolism , Benzoquinones/pharmacology , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Lactams, Macrocyclic/pharmacology , JNK Mitogen-Activated Protein Kinases/metabolism , Myocardial Infarction/metabolism , RNA, Messenger/metabolism , Random Allocation , Tumor Necrosis Factor-alpha/metabolism , Rats, Sprague-Dawley , Inflammation Mediators , Creatine Kinase, MB Form/metabolism , Ischemic Postconditioning/methodsABSTRACT
Abstract Purpose Patients with diabetes are vulnerable to myocardial I/R (ischaemia/reperfusion) injury, but are not responsive to IPO (ischaemic post-conditioning). We hypothesized that decreased cardiac Adiponectin (APN) is responsible for the loss of diabetic heart sensitivity to IPO cardioprotecton. Methods Diabetic rats were subjected to I/R injury (30 min of LAD occlusion followed by 120 min of reperfusion). Myocardial infarct area was determined by TTC staining. Cardiac function was monitored by a microcatheter. ANP, 15-F2t-isoprostane, nitrotyrosine and MDA were measured by assay kits. Levels of p-Akt, total-Akt and GAPDH were determined by Western Blot. Results Diabetic rats subjected to myocardial IR exhibited severe myocardial infarction and oxidative stress injury, lower APN in the plasma and cardiac p-Akt expression ( P <0.05). IPO significantly attenuated myocardial injury and up-regulated plasma APN content and cardiac p-Akt expression in non-diabetic rats but not in diabetic rats. Linear correlation analysis showed that the expression of adiponectin was positively correlated with p-Akt and negatively correlated with myocardial infarction area ( P <0.01). Conclusion Protective effect of IPO was tightly correlated with the expression of adiponectin, exacerbation of I/R injury and ineffectiveness of IPO was partially due to the decline of adiponectin and inactivation of Akt in diabetes mellitus.
Subject(s)
Animals , Male , Rats , Myocardial Reperfusion Injury/prevention & control , Diabetes Mellitus, Experimental/metabolism , Adiponectin/therapeutic use , Ischemic Postconditioning/methods , Blood Glucose/analysis , Myocardial Reperfusion Injury/metabolism , Rats, Sprague-Dawley , Disease Models, AnimalABSTRACT
Mitochondria, as the key passway of neuronal apoptosis after ischemia, is closely related to cerebral ischemia-reperfusion injury. Remote ischemic post-conditioning can alleviate cerebral ischemia-reperfusion injury, and its mechanism is related to alleviating mitochondrial injury and improving its dysfunction. In this paper, cytochrome C/caspase, mitophagy, mitochondrial ATP-sensitive K+ channel and mitochondrial permeability transitionpore were reviewed.
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Background and Objective: Reperfusion therapy for acute myocardial infarction has been shown to reduce mortality, yet it may also have deleterious effects, including myocardial necrosis and no-reflow. Postconditioning is known measure for cardioprotection from reperfusion injury in animal model. Postconditioning is known measure for cardioprotection from reperfusion injury in animal model and human studies have shown inconsistent results. Materials and Methods: From February 2013 through October 2014, at Institute of Postgraduate Medical Education and Research, Kolkata Cardiology department, we randomized 43 patients with acute ST-segment elevation myocardial infarction (STEMI) who were undergoing conventional primary percutaneous coronary intervention (PCI) (22 patients) and PCI with postconditioning by repeated transient balloon occlusion after establishment of flow (21 patients). Total creatine kinase-muscle/brain (CPK-MB) released within 72 h was compared as a surrogate marker of infarct size. Myocardial blush grade between two groups was also compared. Results: The area under curve of serum creatine kinase (CK) release during the 1st 72 h of reperfusion was significantly reduced (P = 0.0347) in the postconditioned group compared with the control group, averaging 9632 IU in postconditioned compared with 13493 IU in control group which represented 29% of reduction of infarct size. The peak of CPK-MB release was markedly lower in the postconditioned (290 ± 16.24 IU/L) than in the control (414.2 ± 51.34 IU/L) group (P ≤ 0.0001). Blush grading was also significantly improved in postconditioned group (P = 0.005). Mean ST-segment deviation at 48 h between cases and control groups was 0.87 ± 0.68 and 1.4 ± 0.94, respectively (P = 0.08). Conclusion: In patients with STEMI, postconditioning significantly improves blush grading and enzymatic infarct size reduction with a trend toward significant reduction of mean ST-segment deviation.
ABSTRACT
Although myocardial ischemic condition can be improved by reperfusion therapy, the sequent myocardial ischemiareperfusion injury may associate with the adverse outcomes in patients with ST-segment elevation myocardial infarction. In the recent years, several therapies, such as ischemia preconditioning and ischemia postconditioning, have been proven effective in animal experiments and have been widely incorporated into clinical trials for the reduction of ischemia/reperfusion injury. Based on the previous clinical evidences, we review the study progress of ischemia conditioning in patients with ST-segment elevation myocardial infarction for optimizing the management of acute myocardial infarction.
ABSTRACT
Objective To establish tree shrew model of type 2 diabetes mellitus (T2DM) combined with cerebral ischemia (IS),and to explore the regulatory mechanism of ischemic postconditioning (PC) on gene differential expression in cerebral cortex under metabolic abnormalities and cerebral ischemia condition.Methods Seventy tree shrews were divided into control,T2DM,IS,T2DM+IS and T2DM +IS +PC groups (n =14 each group).The experimental diabetes model was established by the combined use of high fat diet breeding with streptozocin injection in tree shrew.The local cerebral thrombosis was induced by photochemical reaction in tree shrews,and ischemic PC was established at 4h after cerebral ischemia followed by clipped ipsilateral common carotid artery three times (5 min/time).The metabolic status of tree shrews was measured by serum biochemical markers.TTC staining,HE staining,and electron microscopy were used to observe the changes of the body's metabolic status at 24h after IS.RNA-seq was used to analyze differentially expressed genes.Results The ultrastructure of brain cells was abnormal and the cerebral infarction area was the largest in T2DM+IS tree shrews (P＜0.01).Compared with control group,body weight of tree shrews in T2DM + IS group was significantly reduced (P＜ 0.01) while blood glucose,total cholesterol,low density lipoprotein-cholesterol,triglyceride,and C-reactive protein (CRP) levels were markedly increased(all P＜0.01).The RNA-seq analysis showed that there were 1 629 differentially expressed genes (1 109 up-regulated genes and 520 down-regulated genes) in T2DM + IS group vs control group.However,ischemic PC deceased the cortical infarction area (P＜0.01)and reduced blood glucose,lipid and CRP levels (P＜0.05),with 520 differential expression genes (203 up-regulated genes and 317 down-regulated genes).Conclusion Ischemic PC improves the metabolic disturbance-aggravated ischemic brain injury in T2DM tree shrews,which may be related to its regulation on gene expression in cerebral cortex.