AIM To study the protective effects of tea polyphenol (TP) on cerebral ischemia reperfusion injury in rats and its scavenging oxygen free radical(OFR) activities and antilipid peroxidation in vitro . METHODS Cer...AIM To study the protective effects of tea polyphenol (TP) on cerebral ischemia reperfusion injury in rats and its scavenging oxygen free radical(OFR) activities and antilipid peroxidation in vitro . METHODS Cerebral ischemia reperfusion injury was produced by bilateral ligation of the common carotid arteries with vagus nerves and reperfusion for 45 min. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by thiobarbituric acid spectrophotometry. Superoxide anion (O 2) from xanthine xanthine oxidase system and hydroxyl radical (·OH) from Fe 2+ -H 2O 2 system were determined with spectrophotometry. RESULTS During Cerebral ischemia reperfusion,TP improved the activities of superoxide dismutase ( P 【0 05), GSH peroxidase( P 【0 01) and catalase( P 【0 01), while decreasing the maiondialdchyde content in the brain( P 【0 05) and brain water content ( P 【0 01). Tea polyphenol possessed significantly scavenging effects on ·OH produced by Fenton reaction and O 2 produced by xanthine xanthine oxidase system (the IC 50 were 2 2 mmol·L -1 and 1 9 mmol·L -1 respectively). Tea polyphenol could significant inhibit the lipid peroxidation of cerbral mitochondrial membrane induced by ·OH in a concentration dependent manner. CONCLUSION The results indicate that tea polyphenol could protect the injury on cerebral ischemia reperfusion in rats for OFR, these effects may be related to its scavenging effects on oxygen free radicals and antilipid peroxidant.展开更多
Objective To investigate effects of electroacupuncture (EA) on expression of intercellular adhesion molecule-1 (ICAM-1) in the rat of local cerebral ischemia-reperfusion. Methods Eighty SD rats were randomly divid...Objective To investigate effects of electroacupuncture (EA) on expression of intercellular adhesion molecule-1 (ICAM-1) in the rat of local cerebral ischemia-reperfusion. Methods Eighty SD rats were randomly divided into a normal control group, a sham operation group, a model group and an EA treatment group, 20 rats in each group. The thread-obstruction method was used for preparation of ischemia-reperfusion model. Zea-Longa rating criteria were used for evaluation of nervous function disorder; Immunohistochemical SABC method was used for detection of ICAM-1 expression in the microvascular endothelial cell of the ischemic brain region, and ELISA method for the soluble ICAM-1 (slCAM-1) content in peripheral blood. Re. suits After cerebral ischemia-reperfusion, both ICAM-1 expression level in the microvascular endethelium cell of the ischemic brain region and slCAM-1 content in the peripheral blood significantly increased in the model group as compared with the normal group and the sham operation group (P〈0.01); After EA treatment, the ICAM-1 expression level in the microvascular endothelial cell of the ischemic brain region and slCAM-1 content in the peripheral blood were significantly down-regulated in the EA treatment group as com- pared with the model group (P〈 0.05). Conclusion After cerebral ischemia-reperfusion, the microvascular endothelial cell of the ischemic brain region releases ICAM-1, which induces inflammatory injury of cerebral tissues; EA treatment can decease the expression of ICAM-1, so as to prevent the brain from the injury.展开更多
This study aimed to investigate the protective effects of zin-giberis and acniti praeparatae decoction on oxidative stress injury induced by my-ocardial ischemia reperfusion in rats. [Method] Myocardial ischemia-reper...This study aimed to investigate the protective effects of zin-giberis and acniti praeparatae decoction on oxidative stress injury induced by my-ocardial ischemia reperfusion in rats. [Method] Myocardial ischemia-reperfusion was performed by ligation of the left anterior descending coronary artery for 30 min, fol-lowed by reperfusion for 60 min. The effects of zingiberis and acniti praeparatae decoction on ECG ST segment, myocardial infarction percentage, malondialdehyde (MDA) content in the serum, superoxide dismutase (SOD) activity and other indica-tors were observed. [Result] Zingiberis and acniti praeparatae decoction could effec-tively inhibit ECG ST segment elevation caused by myocardial ischemia-reperfusion injuries, reduce the percentage of myocardial infarction, decline the content of MDA in the serum, and increase the activity of SOD. [Conclusion] Zingiberis and acniti praeparatae decoction exhibits protective effects on oxidative injuries caused by my-ocardial ischemia-reperfusion injuries in rats, which may be involved in reducing the formation of myocardial free radicals and enhancing antioxidant capacity of my-ocardium.展开更多
AIM: To explore the effect of intestinal ischemia-reperfusion injury on protein levels of leptin and orexin-A in peripheral blood and their central secretory tissues and to find out the role leptin and orexin-A play i...AIM: To explore the effect of intestinal ischemia-reperfusion injury on protein levels of leptin and orexin-A in peripheral blood and their central secretory tissues and to find out the role leptin and orexin-A play in acute inflammatory responses.METHODS: An intestinal ischemia-reperfusion (I/R)injury model of rats was established and rats were divided randomly into six groups: sham-operation group, 60 min ischemia/30 min reperfusion group (I60'R30'), I60'R90',I60'R150', I60'R240' and I60'R360', 9 rats each group.Two highly-sensitive radioimmunoassays for leptin and orexin-A were established and used to check the change of their concentrations in peripheral blood and central secretory tissues before and after intestinal I/R injury.RESULTS: Compared with the serum leptin level before injury, it decreased significantly in I60'R30' group and increased significantly in I60'R360' group; compared to sham-operation group after injury, serum leptin level increased significantly in I60'R360' group; compared to sham-operation group after injury, adipose leptin levels decreased significantly in I60'R30' and I60'R90' groups,while increased significantly in I60'R360' group. There was no significant difference between the expression levels of orexin-A before and after I/R injury.CONCLUSION: Leptin has a time-dependent response and orexin-A has a delayed response to acute inflammatory stimuli such as intestinal I/R injury and they may participate in metabolic disorders in injury as inflammatory cytokines.展开更多
AIM: To investigate the hypothesis that the protective effects of curcumin in hepatic warm ischemia/reperfusion (I/R) injury are associated with increasing heat shock protein 70 (Hsp70) expression and antioxidant...AIM: To investigate the hypothesis that the protective effects of curcumin in hepatic warm ischemia/reperfusion (I/R) injury are associated with increasing heat shock protein 70 (Hsp70) expression and antioxidant enzyme activity. METHODS: Sixty Sprague-Dawley male rats were randomly divided into sham, I/R, C + I/R groups. The model of reduced-size liver warm ischemia and reperfusion was used. Curcumin (50 mg/kg) was administered by injection through a branch of superior mesenteric vein at 30 min before ischemia in C + I/R group. Five rats were used to investigate the survival during 1 wk after operation in each group. Blood samples and liver tissues were obtained in the remaining animals after 3, 12, and 24 h of reperfusion to assess serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver tissue NO2- + NO3-, malondialdehyde (MDA) content, superoxide dismutase (SOD), catalase (CAT), nitricoxide synthase (NOS) and myeloperoxidase (MPO) activity, HspT0 expression and apoptosis ratio. RESULTS: Compared with I/R group, curcumin pretreatment group showed less ischemia/reperfusioninduced injury. CAT and SOD activity and Hsp70 expression increased significantly. A higher rate of apoptosis was observed in I/R group than in C + I/R group, and a significant increase of MDA, NO2^- + NO3^- and MPO level in liver tissues and serum transaminase concentration was also observed in I/R group compared to C + I/R group. Curcumin also decreased the activity of inducible NO synthase (iNOS) in liver after reperfusion,but had no effect on the level of endothelial NO synthase (eNOS) after reperfusion in liver. The 7 d survival rate was significantly higher in C + I/R group than in I/R group. CONCLUSION: Curcumin has protective effects against hepatic I/R injury. Its mechanism might be related to the overexpression of Hsp70 and antioxidant enzymes.展开更多
AIM: To investigate the role of nuclear factor kappa B (NF-κB) in the pathogenesis of lung injury induced by intestinal ischemia/reperfusion (I/R), and its effect on intercellular adhesion molecule-1 (ICAM-1) ...AIM: To investigate the role of nuclear factor kappa B (NF-κB) in the pathogenesis of lung injury induced by intestinal ischemia/reperfusion (I/R), and its effect on intercellular adhesion molecule-1 (ICAM-1) expression and neutrophil infiltration. METHODS: Twenty-four Wistar rats were divided randomly into control, I/R and pyrrolidine dithiocarbamate (PDTC) treatment groups, n = 8 in each. I/R group and PDTC treatment group received superior mysenteric artery (SMA) occluding for 1 h and reperfusion for 2 h. PDTC group was administrated with intraperitoneal injection of 2% 100 mg/kg PDTC 1 h before surgery. Lung histology and bronchia alveolus lung fluid (BALF) protein were assayed. Serum IL-6, lung malondialdehyde (MDA) and myeloperoxidase (MPO) as well as the expression level of NF-κB and ICAM-1 were measured.RESULTS: Lung injury induced by intestinal I/R, was characterized by edema, hemorrhage and neutrophil infiltration as well as by the significant rising of BALF protein. Compared to control group, the levels of serum IL-6 and lung MDA and MPO increased significantly in I/R group (P=0.001). Strong positive expression of NF-κB p65 and ICAM-1 was observed. After the administration of PDTC, the level of serum IL-6, lung MDA and MPO as well as NF-κB and ICAM-1 decreased significantly (P〈 0.05) when compared to I/R group.CONCLUSION: The activation of NF-κB plays an important role in the pathogenesis of lung injury induced by intestinal I/R through upregulating the neutrophil infiltration and lung ICAM-1 expression. PDTC as an inhibitor of NF-κB can prevent lung injury induced by intestinal I/R through inhibiting the activity of NF-κB.展开更多
A physiological sequence called autophagy qualitatively determines cellular viability by removing protein aggregates and damaged cyto-plasmic constituents, and contributes significantly to the degree of myocardial isc...A physiological sequence called autophagy qualitatively determines cellular viability by removing protein aggregates and damaged cyto-plasmic constituents, and contributes significantly to the degree of myocardial ischemia-reperfusion (I/R) injury. This tightly orchestrated cata-bolic cellular‘housekeeping’ process provides cells with a new source of energy to adapt to stressful conditions. This process was first described as a pro-survival mechanism, but increasing evidence suggests that it can also lead to the demise of the cell. Autophagy has been implicated in the pathogenesis of multiple cardiac conditions including myocardial I/R injury. However, a debate persists as to whether autophagy acts as a protec-tive mechanism or contributes to the injurious effects of I/R injury in the heart. This controversy may stem from several factors including the va-riability in the experimental models and species, and the methodology used to assess autophagy. This review provides updated knowledge on the modulation and role of autophagy in isolated cardiac cells subjected to I/R, and the growing interest towards manipulating autophagy to increase the survival of cardiac myocytes under conditions of stress-most notably being I/R injury. Perturbation of this evolutionarily conserved intracellular cleansing autophagy mechanism, by targeted modulation through, among others, mammalian target of rapamycin (mTOR) inhibitors, adenosine monophosphate-activated protein kinase (AMPK) modulators, calcium lowering agents, resveratrol, longevinex, sirtuin activators, the proapoptotic gene Bnip3, IP3 and lysosome inhibitors, may confer resistance to heart cells against I/R induced cell death. Thus, therapeutic ma-nipulation of autophagy in the challenged myocardium may benefit post-infarction cardiac healing and remodeling.展开更多
AIM: To investigate the effects of polo-like kinase-1 (PLK1) antisense phosphorothioate oligodeoxynucleotide (ASODN) on apoptosis and cell cycle of human colon cancer cell line SW480. METHODS: After SW480 colon ...AIM: To investigate the effects of polo-like kinase-1 (PLK1) antisense phosphorothioate oligodeoxynucleotide (ASODN) on apoptosis and cell cycle of human colon cancer cell line SW480. METHODS: After SW480 colon cancer cells were transfected with PLK1 ASODN, Northern and Western blot analyses were used to examine PLK1 gene expression in cancer cells. We studied apoptosis using terminal uridine deoxynucleotidyl nick end labeling. Apoptosis and cell cycle of SW480 cells were examined by fluorescence-activated cell sorter scan. RESULTS: The levels of PLK1 mRNA and protein were greatly inhibited by PLK1 ASODN in SW480 cancer cells transfected with PLK1 ASODN. Apoptosis index (AI) induced PLK1 ASODN in a time- and dose-dependent manner. Results from FLM showed that sub-2N DNA content of transfected cancer cells was significantly increased and arrested at G2/M compared with control groups. CONCLUSION: PLK1 ASODN can induce apoptosis of human colon cancer cell line SW480.展开更多
AIM: To study the effects of hepatic ischemia/ reperfusion (I/R) injury on store-operated calcium channel (SOC) currents (Isoc) in freshly isolated rat Kupffer cells, and the effects of Ca^2+ channel blockers,...AIM: To study the effects of hepatic ischemia/ reperfusion (I/R) injury on store-operated calcium channel (SOC) currents (Isoc) in freshly isolated rat Kupffer cells, and the effects of Ca^2+ channel blockers, 2-aminoethoxydiphenyl borate (2-APB), SK&F96365, econazole and miconazole, on Isoc in isolated rat Kupffer cells after hepatic I/R injury.METHODS: The model of rat hepatic I/R injury was established. Whole-cell patch-clamp techniques were performed to investigate the effects of 2-APB, SK&F96365, econazole and miconazole on Isoc in isolated rat Kupffer cells after hepatic I/R injury.RESULTS: I/R injury significantly increased Isoc from -80.4±25.2pA to -159.5±34.5pA (^bp 〈 0.01, n = 30). 2-APB (20, 40, 60, 80, 100 pmol/L), SK&F96365 (5, 10, 20, 40, 50 pmol/L), econazole (0.1, 0.3, 1, 3, 10 μmol/L) and miconazole (0.1, 0.3, 1, 3, 10 μmol/L) inhibited Isoc in a concentration-dependent manner with IC50 of 37.41 μmol/L (n = 8), 5.89 μmol/L (n = 11), 0.21 μmol/L (n = 13), and 0.28 μmol/L (n = 10). The peak value of Isoc in the I-V relationship was decreased by the blockers in different concentrations, but the reverse potential of Isoc was not transformed. CONCLUSION: SOC is the main channel for the influx of Ca^2+ during hepatic I/R injuries. Calcium channel blockers, 2-APB, SK&F96365, econazole and miconazole,have obviously protective effects on I/R injury, probably by inhibiting Isoc in Kupffer cells and preventing the activation of Kupffer cells.展开更多
Objective To clarify the effects of repetitive transcranial magnetic stimulation (rTMS) on rat motor cortical excitabi- lity and neurofunction after cerebral ischemia-reperfusion injury. Methods After determined awake...Objective To clarify the effects of repetitive transcranial magnetic stimulation (rTMS) on rat motor cortical excitabi- lity and neurofunction after cerebral ischemia-reperfusion injury. Methods After determined awake resting motor threshold (MT) and motor evoked potentials (MEPs) of right hindlimbs, 20 Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) reperfusion injury, then rTMS were applied to rTMS group (n = 10) at different time, while control group (n = 10) received no stimulation. A week later, MT and MEPs were evaluated again, as well as neurological deficits and infarct volume. The effects of rTMS and MCAO reperfusion injury on these parameters were analyzed. Results After MCAO reperfusion, both MT level and neurological deficit scores increased, distinct focal infarction formed, and latency of MEP elongated. Compared with the control group, the increased extent of MT and neurological scores of rats receiving rTMS were significantly lower (P < 0.05), as well as the infarct volumes reduced significantly(P < 0.05). But MEP was not affected by rTMS obviously. There was a positive linear correlation between postinjury MT and infarct volume (r = 0.64, P < 0.05). Conclusion rTMS may facilitate neurofunction recovery after cerebral ischemia-reperfusion. Postinjury MT could provide prognostic information after MCAO reperfusion injury.展开更多
AIM: To investigate the effect of shenfu injection on gastrointestinal microcirculation after myocardial ischemic-reperfusion (IR) injury in rabbits and probe into the mechanism. METHODS: Forty healthy flap-eared ...AIM: To investigate the effect of shenfu injection on gastrointestinal microcirculation after myocardial ischemic-reperfusion (IR) injury in rabbits and probe into the mechanism. METHODS: Forty healthy flap-eared white rabbits were randomly divided into 4 groups: IR injury control group (group Ⅰ ), shenfu injection 5 mL/kg per h group (group Ⅱ), shenfu injection 10 mL/kg per h group (group Ⅲ) and shenfu injection 20 mL/kg per h group (group Ⅳ). The four groups were treated with Lactated Ringer's solution, shenfu injection 5, 10, and 20 mL/ kg per h were infused intravenously 30 min before experiment respectively. The values of hemodynamics [mean arterial pressure (MAP), heart rate (HR), gastric intramucosal partial pressure of carbon dioxide (PCO2), blood gas analysis and pH] were measured and compared with those before myocardial ischemia, 60 min after myocardial ischemia and 60, 90, and 180 rain after reperfusion. RESULTS: The MAP, HR and gastric intramucosal pH were (70.50 ± 4.50) kPa, (165 ± 14) beats per rain, 7.032 ± 0.024 in group Ⅰ 60 min after myocardial ischemia, which were significantly decreased compared with those before myocardial ischemia (88.50 ± 9.75 kPa, 217 ± 18 beats per rain, 7.112 ± 0.035, P 〈 0.05). The MAP, HR and gastric intramucosal pH were significantly decreased in group Ⅰ 60, 90, and 180 min after reperfusion (61.50 ± 5.25 kPa, 133 ± 31 beats per rain, 6.997 ± 0.025) compared with those before reperfusion respectively (P 〈 0.05), whereas the values were insignificantly different in groups Ⅱ, Ⅲ or Ⅳ after reperfusion, compared with those before reperfusion, and there were no significant differences between groups Ⅱ, Ⅲ, and Ⅳ after reperfusion. CONCLUSION: Pre-infusion of shenfu injection has a protective effect on gastrointestinal microcirculation after myocardial IR injury in rabbits, in a dose independent manner.展开更多
Background Electroacupuncture pretreatment plays a protective role in myocardial ischemia/reperfusion (I/R) injury and microRNAs (miRNAs) could act on various facets of cardiac function. However, the role of miRNA...Background Electroacupuncture pretreatment plays a protective role in myocardial ischemia/reperfusion (I/R) injury and microRNAs (miRNAs) could act on various facets of cardiac function. However, the role of miRNAs in the cardioprotection by electroacupuncture pre-treatment on myocardial I/R injury remains unknown. The purpose of the study was to examine whether miR-214 was involved in cardio-protection by electroacupuncture. Methods Using rat myocardial I/R model, we examined the role of electroacupuncture pretreatment in myocardial I/R injury and analyzed the changes in the expression of miR-214. In addition, I/R was simulated in vitro by performing oxy-gen-glucose deprivation (OGD) on H9c2 cell cultures, and the effect of electroacupuncture pretreatment on I/R injury as well as expressional level of miR-214 were examined in vitro. Furthermore, the miR-214 mimic was transfected into OGD-treated H9c2 cells, we analyzed the cell apoptosis, lactate dehydrogenase (LDH) and creatine kinase (CK) activities, intracellular free Ca2+concentration ([Ca2+]i) as well as the relative protein levels of sodium/calcium exchanger 1(NCX1), BCL2-like 11 (BIM), calmodulin-dependent protein kinase IIδ(CaMKIIδ) and Cyclophilin D (CypD). Results The in vivo results revealed that compared with the I/R group, the electroacupuncture pretreatment group showed significant decreased myocardial infarct size, as well as the increased indices of the cardiac function, including heart rate, mean arterial pressure, left ventricular systolic pressure and maximal rate for left ventricular pressure rising and declining (±dp/dt max). In addition, electroacupuncture pretreatment could inhibit the elevation of LDH and CK activities induced by I/R injury. The quantitative PCR (qPCR) results demonstrated electroacupuncture pretreatment could provide cardioprotection against myocardial I/R injury in rats with miR-214 up-regulation. In the meanwhile, in vitro, electroacupuncture pretreatment protected H9c2 cells from OGD-induced injury. Trans-fection of miR-214 mimic showed protective effects on OGD-induced injury to H9c2 cells by reducing apoptosis, decreasing LDH and CK activities, rescuing the OGD-induced Ca2+and down-regulating elevated protein levels of NCX1, BIM, CaMKIIδand CypD. Conclusions Our findings firstly demonstrated that electroacupuncture pretreatment promotes the expression of miR-214 in myocardial I/R injury and miR-214 contributes to the protective effect of electroacupuncture on myocardial I/R injury.展开更多
文摘AIM To study the protective effects of tea polyphenol (TP) on cerebral ischemia reperfusion injury in rats and its scavenging oxygen free radical(OFR) activities and antilipid peroxidation in vitro . METHODS Cerebral ischemia reperfusion injury was produced by bilateral ligation of the common carotid arteries with vagus nerves and reperfusion for 45 min. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by thiobarbituric acid spectrophotometry. Superoxide anion (O 2) from xanthine xanthine oxidase system and hydroxyl radical (·OH) from Fe 2+ -H 2O 2 system were determined with spectrophotometry. RESULTS During Cerebral ischemia reperfusion,TP improved the activities of superoxide dismutase ( P 【0 05), GSH peroxidase( P 【0 01) and catalase( P 【0 01), while decreasing the maiondialdchyde content in the brain( P 【0 05) and brain water content ( P 【0 01). Tea polyphenol possessed significantly scavenging effects on ·OH produced by Fenton reaction and O 2 produced by xanthine xanthine oxidase system (the IC 50 were 2 2 mmol·L -1 and 1 9 mmol·L -1 respectively). Tea polyphenol could significant inhibit the lipid peroxidation of cerbral mitochondrial membrane induced by ·OH in a concentration dependent manner. CONCLUSION The results indicate that tea polyphenol could protect the injury on cerebral ischemia reperfusion in rats for OFR, these effects may be related to its scavenging effects on oxygen free radicals and antilipid peroxidant.
文摘Objective To investigate effects of electroacupuncture (EA) on expression of intercellular adhesion molecule-1 (ICAM-1) in the rat of local cerebral ischemia-reperfusion. Methods Eighty SD rats were randomly divided into a normal control group, a sham operation group, a model group and an EA treatment group, 20 rats in each group. The thread-obstruction method was used for preparation of ischemia-reperfusion model. Zea-Longa rating criteria were used for evaluation of nervous function disorder; Immunohistochemical SABC method was used for detection of ICAM-1 expression in the microvascular endothelial cell of the ischemic brain region, and ELISA method for the soluble ICAM-1 (slCAM-1) content in peripheral blood. Re. suits After cerebral ischemia-reperfusion, both ICAM-1 expression level in the microvascular endethelium cell of the ischemic brain region and slCAM-1 content in the peripheral blood significantly increased in the model group as compared with the normal group and the sham operation group (P〈0.01); After EA treatment, the ICAM-1 expression level in the microvascular endothelial cell of the ischemic brain region and slCAM-1 content in the peripheral blood were significantly down-regulated in the EA treatment group as com- pared with the model group (P〈 0.05). Conclusion After cerebral ischemia-reperfusion, the microvascular endothelial cell of the ischemic brain region releases ICAM-1, which induces inflammatory injury of cerebral tissues; EA treatment can decease the expression of ICAM-1, so as to prevent the brain from the injury.
基金Supported by Scientific Research Project of Guiyang College of Traditional Chinese Medicine[(2010)02]~~
文摘This study aimed to investigate the protective effects of zin-giberis and acniti praeparatae decoction on oxidative stress injury induced by my-ocardial ischemia reperfusion in rats. [Method] Myocardial ischemia-reperfusion was performed by ligation of the left anterior descending coronary artery for 30 min, fol-lowed by reperfusion for 60 min. The effects of zingiberis and acniti praeparatae decoction on ECG ST segment, myocardial infarction percentage, malondialdehyde (MDA) content in the serum, superoxide dismutase (SOD) activity and other indica-tors were observed. [Result] Zingiberis and acniti praeparatae decoction could effec-tively inhibit ECG ST segment elevation caused by myocardial ischemia-reperfusion injuries, reduce the percentage of myocardial infarction, decline the content of MDA in the serum, and increase the activity of SOD. [Conclusion] Zingiberis and acniti praeparatae decoction exhibits protective effects on oxidative injuries caused by my-ocardial ischemia-reperfusion injuries in rats, which may be involved in reducing the formation of myocardial free radicals and enhancing antioxidant capacity of my-ocardium.
基金Supported by the National Natural Science Foundation of China,No.39970717
文摘AIM: To explore the effect of intestinal ischemia-reperfusion injury on protein levels of leptin and orexin-A in peripheral blood and their central secretory tissues and to find out the role leptin and orexin-A play in acute inflammatory responses.METHODS: An intestinal ischemia-reperfusion (I/R)injury model of rats was established and rats were divided randomly into six groups: sham-operation group, 60 min ischemia/30 min reperfusion group (I60'R30'), I60'R90',I60'R150', I60'R240' and I60'R360', 9 rats each group.Two highly-sensitive radioimmunoassays for leptin and orexin-A were established and used to check the change of their concentrations in peripheral blood and central secretory tissues before and after intestinal I/R injury.RESULTS: Compared with the serum leptin level before injury, it decreased significantly in I60'R30' group and increased significantly in I60'R360' group; compared to sham-operation group after injury, serum leptin level increased significantly in I60'R360' group; compared to sham-operation group after injury, adipose leptin levels decreased significantly in I60'R30' and I60'R90' groups,while increased significantly in I60'R360' group. There was no significant difference between the expression levels of orexin-A before and after I/R injury.CONCLUSION: Leptin has a time-dependent response and orexin-A has a delayed response to acute inflammatory stimuli such as intestinal I/R injury and they may participate in metabolic disorders in injury as inflammatory cytokines.
文摘AIM: To investigate the hypothesis that the protective effects of curcumin in hepatic warm ischemia/reperfusion (I/R) injury are associated with increasing heat shock protein 70 (Hsp70) expression and antioxidant enzyme activity. METHODS: Sixty Sprague-Dawley male rats were randomly divided into sham, I/R, C + I/R groups. The model of reduced-size liver warm ischemia and reperfusion was used. Curcumin (50 mg/kg) was administered by injection through a branch of superior mesenteric vein at 30 min before ischemia in C + I/R group. Five rats were used to investigate the survival during 1 wk after operation in each group. Blood samples and liver tissues were obtained in the remaining animals after 3, 12, and 24 h of reperfusion to assess serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver tissue NO2- + NO3-, malondialdehyde (MDA) content, superoxide dismutase (SOD), catalase (CAT), nitricoxide synthase (NOS) and myeloperoxidase (MPO) activity, HspT0 expression and apoptosis ratio. RESULTS: Compared with I/R group, curcumin pretreatment group showed less ischemia/reperfusioninduced injury. CAT and SOD activity and Hsp70 expression increased significantly. A higher rate of apoptosis was observed in I/R group than in C + I/R group, and a significant increase of MDA, NO2^- + NO3^- and MPO level in liver tissues and serum transaminase concentration was also observed in I/R group compared to C + I/R group. Curcumin also decreased the activity of inducible NO synthase (iNOS) in liver after reperfusion,but had no effect on the level of endothelial NO synthase (eNOS) after reperfusion in liver. The 7 d survival rate was significantly higher in C + I/R group than in I/R group. CONCLUSION: Curcumin has protective effects against hepatic I/R injury. Its mechanism might be related to the overexpression of Hsp70 and antioxidant enzymes.
基金Supported by The Natural Science Foundation of Liaoning Province,No.20042135
文摘AIM: To investigate the role of nuclear factor kappa B (NF-κB) in the pathogenesis of lung injury induced by intestinal ischemia/reperfusion (I/R), and its effect on intercellular adhesion molecule-1 (ICAM-1) expression and neutrophil infiltration. METHODS: Twenty-four Wistar rats were divided randomly into control, I/R and pyrrolidine dithiocarbamate (PDTC) treatment groups, n = 8 in each. I/R group and PDTC treatment group received superior mysenteric artery (SMA) occluding for 1 h and reperfusion for 2 h. PDTC group was administrated with intraperitoneal injection of 2% 100 mg/kg PDTC 1 h before surgery. Lung histology and bronchia alveolus lung fluid (BALF) protein were assayed. Serum IL-6, lung malondialdehyde (MDA) and myeloperoxidase (MPO) as well as the expression level of NF-κB and ICAM-1 were measured.RESULTS: Lung injury induced by intestinal I/R, was characterized by edema, hemorrhage and neutrophil infiltration as well as by the significant rising of BALF protein. Compared to control group, the levels of serum IL-6 and lung MDA and MPO increased significantly in I/R group (P=0.001). Strong positive expression of NF-κB p65 and ICAM-1 was observed. After the administration of PDTC, the level of serum IL-6, lung MDA and MPO as well as NF-κB and ICAM-1 decreased significantly (P〈 0.05) when compared to I/R group.CONCLUSION: The activation of NF-κB plays an important role in the pathogenesis of lung injury induced by intestinal I/R through upregulating the neutrophil infiltration and lung ICAM-1 expression. PDTC as an inhibitor of NF-κB can prevent lung injury induced by intestinal I/R through inhibiting the activity of NF-κB.
文摘A physiological sequence called autophagy qualitatively determines cellular viability by removing protein aggregates and damaged cyto-plasmic constituents, and contributes significantly to the degree of myocardial ischemia-reperfusion (I/R) injury. This tightly orchestrated cata-bolic cellular‘housekeeping’ process provides cells with a new source of energy to adapt to stressful conditions. This process was first described as a pro-survival mechanism, but increasing evidence suggests that it can also lead to the demise of the cell. Autophagy has been implicated in the pathogenesis of multiple cardiac conditions including myocardial I/R injury. However, a debate persists as to whether autophagy acts as a protec-tive mechanism or contributes to the injurious effects of I/R injury in the heart. This controversy may stem from several factors including the va-riability in the experimental models and species, and the methodology used to assess autophagy. This review provides updated knowledge on the modulation and role of autophagy in isolated cardiac cells subjected to I/R, and the growing interest towards manipulating autophagy to increase the survival of cardiac myocytes under conditions of stress-most notably being I/R injury. Perturbation of this evolutionarily conserved intracellular cleansing autophagy mechanism, by targeted modulation through, among others, mammalian target of rapamycin (mTOR) inhibitors, adenosine monophosphate-activated protein kinase (AMPK) modulators, calcium lowering agents, resveratrol, longevinex, sirtuin activators, the proapoptotic gene Bnip3, IP3 and lysosome inhibitors, may confer resistance to heart cells against I/R induced cell death. Thus, therapeutic ma-nipulation of autophagy in the challenged myocardium may benefit post-infarction cardiac healing and remodeling.
文摘AIM: To investigate the effects of polo-like kinase-1 (PLK1) antisense phosphorothioate oligodeoxynucleotide (ASODN) on apoptosis and cell cycle of human colon cancer cell line SW480. METHODS: After SW480 colon cancer cells were transfected with PLK1 ASODN, Northern and Western blot analyses were used to examine PLK1 gene expression in cancer cells. We studied apoptosis using terminal uridine deoxynucleotidyl nick end labeling. Apoptosis and cell cycle of SW480 cells were examined by fluorescence-activated cell sorter scan. RESULTS: The levels of PLK1 mRNA and protein were greatly inhibited by PLK1 ASODN in SW480 cancer cells transfected with PLK1 ASODN. Apoptosis index (AI) induced PLK1 ASODN in a time- and dose-dependent manner. Results from FLM showed that sub-2N DNA content of transfected cancer cells was significantly increased and arrested at G2/M compared with control groups. CONCLUSION: PLK1 ASODN can induce apoptosis of human colon cancer cell line SW480.
基金the National Natural Science Foundation of China,No.30270532 Trans-Century Training Programme Foundation for the Talents by the Ministry of Education of China, No. 2002-48Shuguang Program Project of Shanghai Educational Committee,No.02SG20
文摘AIM: To study the effects of hepatic ischemia/ reperfusion (I/R) injury on store-operated calcium channel (SOC) currents (Isoc) in freshly isolated rat Kupffer cells, and the effects of Ca^2+ channel blockers, 2-aminoethoxydiphenyl borate (2-APB), SK&F96365, econazole and miconazole, on Isoc in isolated rat Kupffer cells after hepatic I/R injury.METHODS: The model of rat hepatic I/R injury was established. Whole-cell patch-clamp techniques were performed to investigate the effects of 2-APB, SK&F96365, econazole and miconazole on Isoc in isolated rat Kupffer cells after hepatic I/R injury.RESULTS: I/R injury significantly increased Isoc from -80.4±25.2pA to -159.5±34.5pA (^bp 〈 0.01, n = 30). 2-APB (20, 40, 60, 80, 100 pmol/L), SK&F96365 (5, 10, 20, 40, 50 pmol/L), econazole (0.1, 0.3, 1, 3, 10 μmol/L) and miconazole (0.1, 0.3, 1, 3, 10 μmol/L) inhibited Isoc in a concentration-dependent manner with IC50 of 37.41 μmol/L (n = 8), 5.89 μmol/L (n = 11), 0.21 μmol/L (n = 13), and 0.28 μmol/L (n = 10). The peak value of Isoc in the I-V relationship was decreased by the blockers in different concentrations, but the reverse potential of Isoc was not transformed. CONCLUSION: SOC is the main channel for the influx of Ca^2+ during hepatic I/R injuries. Calcium channel blockers, 2-APB, SK&F96365, econazole and miconazole,have obviously protective effects on I/R injury, probably by inhibiting Isoc in Kupffer cells and preventing the activation of Kupffer cells.
文摘Objective To clarify the effects of repetitive transcranial magnetic stimulation (rTMS) on rat motor cortical excitabi- lity and neurofunction after cerebral ischemia-reperfusion injury. Methods After determined awake resting motor threshold (MT) and motor evoked potentials (MEPs) of right hindlimbs, 20 Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) reperfusion injury, then rTMS were applied to rTMS group (n = 10) at different time, while control group (n = 10) received no stimulation. A week later, MT and MEPs were evaluated again, as well as neurological deficits and infarct volume. The effects of rTMS and MCAO reperfusion injury on these parameters were analyzed. Results After MCAO reperfusion, both MT level and neurological deficit scores increased, distinct focal infarction formed, and latency of MEP elongated. Compared with the control group, the increased extent of MT and neurological scores of rats receiving rTMS were significantly lower (P < 0.05), as well as the infarct volumes reduced significantly(P < 0.05). But MEP was not affected by rTMS obviously. There was a positive linear correlation between postinjury MT and infarct volume (r = 0.64, P < 0.05). Conclusion rTMS may facilitate neurofunction recovery after cerebral ischemia-reperfusion. Postinjury MT could provide prognostic information after MCAO reperfusion injury.
文摘AIM: To investigate the effect of shenfu injection on gastrointestinal microcirculation after myocardial ischemic-reperfusion (IR) injury in rabbits and probe into the mechanism. METHODS: Forty healthy flap-eared white rabbits were randomly divided into 4 groups: IR injury control group (group Ⅰ ), shenfu injection 5 mL/kg per h group (group Ⅱ), shenfu injection 10 mL/kg per h group (group Ⅲ) and shenfu injection 20 mL/kg per h group (group Ⅳ). The four groups were treated with Lactated Ringer's solution, shenfu injection 5, 10, and 20 mL/ kg per h were infused intravenously 30 min before experiment respectively. The values of hemodynamics [mean arterial pressure (MAP), heart rate (HR), gastric intramucosal partial pressure of carbon dioxide (PCO2), blood gas analysis and pH] were measured and compared with those before myocardial ischemia, 60 min after myocardial ischemia and 60, 90, and 180 rain after reperfusion. RESULTS: The MAP, HR and gastric intramucosal pH were (70.50 ± 4.50) kPa, (165 ± 14) beats per rain, 7.032 ± 0.024 in group Ⅰ 60 min after myocardial ischemia, which were significantly decreased compared with those before myocardial ischemia (88.50 ± 9.75 kPa, 217 ± 18 beats per rain, 7.112 ± 0.035, P 〈 0.05). The MAP, HR and gastric intramucosal pH were significantly decreased in group Ⅰ 60, 90, and 180 min after reperfusion (61.50 ± 5.25 kPa, 133 ± 31 beats per rain, 6.997 ± 0.025) compared with those before reperfusion respectively (P 〈 0.05), whereas the values were insignificantly different in groups Ⅱ, Ⅲ or Ⅳ after reperfusion, compared with those before reperfusion, and there were no significant differences between groups Ⅱ, Ⅲ, and Ⅳ after reperfusion. CONCLUSION: Pre-infusion of shenfu injection has a protective effect on gastrointestinal microcirculation after myocardial IR injury in rabbits, in a dose independent manner.
基金This study was supported by a grant from the Hainan Provincial Nature Science Foundation
文摘Background Electroacupuncture pretreatment plays a protective role in myocardial ischemia/reperfusion (I/R) injury and microRNAs (miRNAs) could act on various facets of cardiac function. However, the role of miRNAs in the cardioprotection by electroacupuncture pre-treatment on myocardial I/R injury remains unknown. The purpose of the study was to examine whether miR-214 was involved in cardio-protection by electroacupuncture. Methods Using rat myocardial I/R model, we examined the role of electroacupuncture pretreatment in myocardial I/R injury and analyzed the changes in the expression of miR-214. In addition, I/R was simulated in vitro by performing oxy-gen-glucose deprivation (OGD) on H9c2 cell cultures, and the effect of electroacupuncture pretreatment on I/R injury as well as expressional level of miR-214 were examined in vitro. Furthermore, the miR-214 mimic was transfected into OGD-treated H9c2 cells, we analyzed the cell apoptosis, lactate dehydrogenase (LDH) and creatine kinase (CK) activities, intracellular free Ca2+concentration ([Ca2+]i) as well as the relative protein levels of sodium/calcium exchanger 1(NCX1), BCL2-like 11 (BIM), calmodulin-dependent protein kinase IIδ(CaMKIIδ) and Cyclophilin D (CypD). Results The in vivo results revealed that compared with the I/R group, the electroacupuncture pretreatment group showed significant decreased myocardial infarct size, as well as the increased indices of the cardiac function, including heart rate, mean arterial pressure, left ventricular systolic pressure and maximal rate for left ventricular pressure rising and declining (±dp/dt max). In addition, electroacupuncture pretreatment could inhibit the elevation of LDH and CK activities induced by I/R injury. The quantitative PCR (qPCR) results demonstrated electroacupuncture pretreatment could provide cardioprotection against myocardial I/R injury in rats with miR-214 up-regulation. In the meanwhile, in vitro, electroacupuncture pretreatment protected H9c2 cells from OGD-induced injury. Trans-fection of miR-214 mimic showed protective effects on OGD-induced injury to H9c2 cells by reducing apoptosis, decreasing LDH and CK activities, rescuing the OGD-induced Ca2+and down-regulating elevated protein levels of NCX1, BIM, CaMKIIδand CypD. Conclusions Our findings firstly demonstrated that electroacupuncture pretreatment promotes the expression of miR-214 in myocardial I/R injury and miR-214 contributes to the protective effect of electroacupuncture on myocardial I/R injury.