油茶皂苷抗心肌缺血大鼠氧自由基和脂质过氧化作用

目的　以皮下注射异丙肾上腺素 (ISO)诱发大鼠心肌损伤为模型 ,观察油茶皂苷 (SQS)对心肌线粒体MDA含量、SOD、GSH Px活性的影响。方法　实验分生理盐水组 (NS组 )、ISO诱发损伤组 (I/R组 )、SQSⅠ组 (I/R +SQS 0 1mg·kg-1)和SQSⅡ组 (I/R +SQS 0 2mg·kg-1)。从阴茎静脉注射各被试药物或NS ,每天 1次 ,连续 3d。末次给药后取心肌组织行上述指标的测定。结果　I/R组MDA含量明显升高、SOD及GSH Px活性显著降低 ;SQS能对抗ISO所致上述指标的改变 ,且呈剂量依赖关系。结论　SQS具有抗ISO所致大鼠心肌缺血时氧自由基和脂质过氧化作用     

Hydrogen sulfide alleviates uranium‐induced acute hepatotoxicity in rats: Role of antioxidant and antiapoptotic signaling

As an endogenous gaseous mediator, H₂S exerts antioxidative, antiapoptotic, and cytoprotective effects in livers. This study was designed to investigate the protective role of H₂S against uranium‐induced hepatotoxicity in adult SD male rats after in vivo effect of uranium on endogenous H₂S production was determined in livers. The levels of endogenous H₂S and H₂S‐producing enzymes (CBS and CSE) were measured in liver homogenates from uranium ‐intoxicated rats. In rats injected intraperitoneally (i.p.) with uranyl acetate or NaHS (an H₂S donor) alone or in combination, we examined biochemical parameters to assess liver function, revealed hepatic histopathological alteration, investigated oxidative stress markers, and explored apoptotic signaling in liver homogenates. The results suggest that uranium‐intoxication in rats decreased CBS and CSE protein expression, H₂S synthesis capacity, and endogenous H₂S generation. NaHS administration in uranium‐intoxicated rats produced amelioration in liver biochemical indices and histopathological effects, decreased MDA content, and increased GSH level and antioxidative enzymes activities like SOD, CAT, GPx, and GST. NaHS administration in uranium‐intoxicated rats attenuated uranium‐activated phosphorylation state of JNK. NaHS treatment in uranium‐intoxicated rats increased antiapoptotic Bcl‐2 but decreased pro‐apoptotic Bax, resulting in the rise of Bcl‐2/Bax ratio. NaHS treatment in uranium‐intoxicated rats reduced the apoptosis mediator caspase‐3 and cytochrome c release and elevated ATP contents. Taken together, these data implicate that H₂S can afford protection to rat livers against uranium‐induced adverse effects mediated by up‐regulation of antioxidant and antiapoptotic signaling. The anti‐apoptotic property of H₂S may be involved, at least in part, in inhibiting JNK signaling. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 581–593, 2017.     

前列腺素E_1对脑缺血再灌注损伤的保护作用

目的　探讨前列腺素E1 (PGE1 )在脑缺血再灌注损伤中对脑组织过氧化的影响、对脑细胞膜ATP酶的保护、对血浆炎性细胞因子及内皮素的干预作用。方法　采用线栓法阻断大鼠左侧大脑中动脉 ,造成局灶性脑缺血再灌注模型 ,用药组于缺血前 5minivgttPGE1 (1 2 ,2 4 ,48μg·kg- 1 ) ,模型组及假手术组给予等容积NS。各组在大脑中动脉阻塞(MCAO) 60min ,再灌注 60min后 ,断头、取脑匀浆 ,测定其丙二醛 (MDA)含量 ,总超氧化物歧化酶 (SOD)活性 ,谷胱甘肽过氧化物酶 (GSH Px)活性及Na+ ,K+ ATP酶 ,Ca2 + ATP酶 ,Mg2 + ATP酶活性。心脏取血分离血浆测定其肿瘤坏死因子 (TNFα)的浓度及白介素 (IL 1 β、IL 6)和血浆内皮素 (ET 1 )的含量。结果　缺血再灌注模型组与假手术组相比 ,MDA含量升高 (P <0 0 5)、SOD及GSH Px活力降低 (P<0 0 5) ,Na+ ,K+ ATP酶、Ca2 + ATP酶、Mg2 + ATP酶活性降低 (P <0 0 5) ,TNFα、IL 1 β、ET 1含量升高 (P <0 0 5)。PGE1 3剂量组与模型组相比 ,MDA含量降低 (P <0 0 5) ,SOD及GSH Px活力升高 (P <0 0 5) ,Na+ ,K+ ATP酶、Ca2 + ATP酶、Mg2 + ATP酶活性升高 (P <0 0 5 ) ,Mg2 + ATP酶活性亦升高 ,TNFα、IL 1 β、ET 1含量降低 (P<0 0 5)。结论　PGE1 对缺血再灌注?     

Molecular Mechanisms of Hydrogen Sulfide Toxicity

Rationale. The toxicity of H2S has been attributed to its ability to inhibit cytochrome c oxidase in a similar manner to HCN. However, the successful use of methemoglobin for the treatment of HCN poisoning was not successful for H2S poisonings even though the ferric heme group of methemoglobin scavenges H2S. Thus, we speculated that other mechanisms contribute to H2S induced cytotoxicity. Experimental procedure. Hepatocyte isolation and viability and enzyme activities were measured as described by , and . Results. Incubation of isolated hepatocytes with NaHS solutions (a H₂S source) resulted in glutathione (GSH) depletion. Moreover, GSH depletion was also observed in TRIS-HCl buffer (pH 6.0) treated with NaHS. Several ferric chelators (desferoxamime and DETAPAC) and antioxidant enzymes (superoxide dismutase [SOD] and catalase) prevented cell-free and hepatocyte GSH depletion. GSH-depleted hepatocytes were very susceptible to NaHS cytotoxicity, indicating that GSH detoxified NaHS or H₂S in cells. Cytotoxicity was also partly prevented by desferoxamine and DETAPC, but it was increased by ferric EDTA or EDTA. Cell-free oxygen consumption experiments in TRIS-HCl buffer showed that NaHS autoxidation formed hydrogen peroxide and was prevented by DETAPC but increased by EDTA. We hypothesize that H₂S can reduce intracellular bound ferric iron to form unbound ferrous iron, which activates iron. Additionally, H₂S can increase the hepatocyte formation of reactive oxygen species (ROS) (known to occur with electron transport chain). H₂S cytotoxicity therefore also involves a reactive sulfur species, which depletes GSH and activates oxygen to form ROS.     

Dual effects of hydrogen sulphide on focal cerebral ischaemic injury via modulation of oxidative stress-induced apoptosis

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Galanin receptors activation modulates myocardial metabolic and antioxidant responses to ischaemia/reperfusion stress

The mechanisms of protective action of the neuropeptide galanin and its N‐terminal fragments against myocardial ischaemia/reperfusion (I/R) injury remain obscure. The aim of this work was to study effects of a novel peptide agonist of galanin receptors [βAla14, His15]‐galanin (2‐15) (G1) and the full‐length galanin (G2) on energy and antioxidant status of the heart with acute infarction. The peptides were synthesized by the automatic solid phase method using Fmoc technology. Their structure was identified by ¹H‐NMR spectroscopy and MALDI‐TOF mass spectrometry. Experiments were performed on anaesthetized open‐chest rats subjected to myocardial regional ischaemia and reperfusion. Intravenous (iv) administration of optimal doses of peptides G1 and G2 (1.0 and 0.5 mg/kg, respectively, at the onset of reperfusion significantly reduced infarct size (on average by 40% compared with control) and the plasma activity of creatine kinase‐MB (CK‐MB) and lactate dehydrogenase (LDH). These effects were associated with augmented preservation of aerobic energy metabolism, increased activity of Cu,Zn superoxide dismutase (Cu,Zn‐SOD), catalase (CAT) and glutathione peroxidase (GSH‐Px) and decreased lipid peroxidation in the area at risk (AAR) at the end of reperfusion. Peptide G1 showed more efficient recovery of the majority of metabolic and antioxidant parameters. The results provide evidence that the galaninergic system can be considered a promising target to reduce energy dysregulation and oxidative damage in myocardial I/R injury.     

人参皂苷Rg1对大鼠肠缺血/再灌注损伤的影响

目的观察人参皂苷Rg1(ginsenoside Rg1)对大鼠肠缺血/再灌注后肠组织损伤的影响,并探讨其机制。方法制备SD大鼠肠缺血/再灌注损伤模型。实验分为3组(n=10):假手术组、缺血/再灌注组(对照组)、人参皂苷Rg1干预组(治疗组)。比较各组大鼠肠黏膜肿瘤坏死因子α(TNF-α)水平、白细胞介素6(IL-6)水平、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性的变化;用Chiu氏评分法观察肠黏膜的损伤情况。结果与假手术组相比,对照组TNF-α、IL-6水平明显升高,MDA含量明显增高,SOD活性明显降低,小肠损伤评分明显升高;与对照组相比,治疗组TNF-α、IL-6水平明显降低,MDA含量明显降低,SOD活性明显升高,小肠损伤评分明显降低。结论人参皂苷Rg1对大鼠肠缺血/再灌注后的肠道有保护作用,该保护作用可能与减少TNF-α、IL-6、MDA含量,提高SOD活性有关。     

Effect of thymoquinone on hepatorenal dysfunction and alteration of CYP3A1 and spermidine/spermine N-1-acetyl-transferase gene expression induced by renal ischaemia-reperfusion in rats

Objectives Renal ischaemia–reperfusion (I/R) is a well‐characterised model of acute renal failure that causes both local and remote organ injury. The aim of this work was to investigate the effect of thymoquinone, the main constituent of the volatile oil extracted from Nigella sativa seeds, on renal and hepatic changes after renal ischaemia–reperfusion. Methods Male Sprague‐Dawley rats were divided into sham I/R vehicle‐treated groups, and I/R thymoquinone‐treated groups. Thymoquinone (10 mg/kg, p.o.) was administered for ten consecutive days to the I/R thymoquinone group before injury. I/R and I/R thymoquinone groups were subjected to 30‐min ischaemia followed by 4‐h reperfusion. Key findings I/R resulted in a significant increase in malondialdehyde (MDA) level and decreases in glutathione‐S‐transferase (GST) and superoxide dismutase (SOD) activity in liver and kidney tissues. Thymoquinone treatment caused the reversal of I/R‐induced changes in MDA as well as GST and SOD activity. Moreover, I/R caused a significant rise in creatinine and alanine aminotransferase serum levels. CYP3A1 mRNA expression was induced significantly by I/R in both liver and kidney tissues compared with sham group. Thymoquinone reduced significantly this increase. I/R caused induction of mRNA expression of spermidine/spermine N‐1‐acetyl‐transferase (SSAT), a catabolic enzyme that participates in polyamine metabolism, in liver and kidney tissues. Thymoquinone reduced SSAT mRNA expression significantly in liver and markedly in kidney. Conclusions These findings suggested that thymoquinone protected against renal I/R‐induced damage through an antioxidant mechanism as well as the decrease of CYP3A1 and SSAT gene expression.     

前列地尔对大鼠肾缺血再灌注损伤的保护作用

目的观察前列地尔对大鼠肾缺血再灌注损伤的保护作用。方法首先建立大鼠肾缺血再灌注损伤动物模型,并将实验大鼠随机分为3组,即正常对照组(Control)、肾缺血再灌注损伤组(I/R)和前列地尔治疗组(前列地尔+I/R)。实验结束后检测大鼠血浆及肾组织中脂质过氧化代谢产物丙二醛(MDA)和超氧化物歧化酶(SOD)的活性,并观察大鼠肾脏组织结构的变化。结果大鼠发生肾脏缺血再灌注损伤时,血浆和肾组织中脂质过氧化代谢产物MDA的含量明显升高(P<0.05),而SOD的活性则明显降低(P<0.05)。在大鼠肾脏缺血再灌注损伤前预先给予前列地尔,能够明显抑制上述指标的变化,同时可以减轻大鼠肾脏组织超微结构的损伤。结论前列地尔可以降低大鼠血浆和肾组织中MDA的含量,升高SOD的水平,对大鼠肾缺血再灌注损伤具有明显的保护作用。     

Hydrogen sulphide protects H9c2 cells against chemical hypoxia‐induced injury

1. The aim of the present study was to investigate the effect of hydrogen sulphide (H₂S) on cobalt chloride (CoCl₂)‐induced injury in H9c2 embryonic rat cardiac cells. 2. After 36 h incubation in the presence of 600 μmol/L CoCl₂, reduced cell viability of H9c2 cells was observed, as well as the induction of apoptosis. In addition, CoCl₂ (600 μmol/L) enhanced the production of reactive oxygen species (ROS) and the expression of cleaved caspase 3, induced a loss of mitochondrial membrane potential (MMP) and decreased reduced glutathione (GSH) production. These results suggest that CoCl₂ induces similar responses to hypoxia/ischaemia. 3. Pretreatment of cells with 400 μmol/L NaHS (a H₂S donor) for 30 min prior to exposure to CoCl₂ (600 μmol/L) significantly protected H9c2 cells against CoCl₂‐induced injury. Specifically, increased cell viability and decreased apoptosis were observed. In addition, NaHS pretreatment blocked the CoCl₂‐induced increases in ROS production and cleaved caspase 3 expression, as well as the decreases in GSH production and loss of MMP. 4. Pretreatment of cells with 2000 μmol/L N‐acetylcysteine (NAC), a ROS scavenger, for 1 h prior to CoCl₂ exposure significantly protected H9c2 cells against CoCl₂‐induced injury, specifically enhancing cell viability, decreasing ROS production and preventing loss of MMP. 5. The findings of the present study suggest that H₂S protects H9c2 cells against CoCl₂‐induced injury by suppressing oxidative stress and caspase 3 activation.     

前列腺素E_1、川芎嗪合用对大鼠心肌缺血再灌注损伤的保护作用

目的观察前列腺素Ｅ１（３１２５μｇ·ｋｇ－１）与川芎嗪（２５ｍｇ·ｋｇ－１）合用对大鼠心肌缺血再灌注损伤的影响。方法麻醉大鼠冠脉结扎３０ｍｉｎ后，再灌６０ｍｉｎ诱发心律失常，硫代巴比妥酸法和分光光度法分别测定ＭＤＡ、ＳＯＤ及ＧＳＨ Ｐｘ，原子吸收光度法测定心肌细胞内Ｃａ２＋含量。结果两药小剂量合用的效果优于各药较大剂量单用。联合用药不仅更显著提高缺血再灌心肌ＳＯＤ、ＧＳＨ Ｐｘ活力（Ｐ＜００１），尚可显著降低ＭＤＡ、Ｃａ２＋及血清ＣＫ ＭＢ含量（Ｐ＜００１），防止缺血再灌室性心律失常的发生（Ｐ＜００１）。结论前列腺素Ｅ１与川芎嗪合用对心肌缺血再灌注损伤的保护作用有显著的协同作用。其作用与提高自由基清除酶活性、抑制脂质过氧化反应和防止心肌细胞内“钙超负荷”有关     

Hydrogen sulfide ameliorates disorders in the parafacial respiratory group region of neonatal rats caused by prenatal cigarette smoke exposure via an antioxidative effect

We previously found that hydrogen sulfide (H₂S) ameliorated the dysfunction of central chemoreception caused by prenatal cigarette smoke exposure (CSE). In the present study, we further explored whether the parafacial respiratory group (pFRG) is involved in the protection of central chemoreception by H₂S against prenatal CSE-induced injury. We found that NaHS, a donor of H₂S, restored the expression of Phox2b, which was downregulated by prenatal CSE, in the pFRG region of neonatal rats. NaHS also relieved the prenatal CSE-induced excitatory synapse disturbance in the pFRG region of neonatal rats. Additionally, NaHS prevented the increase in the malondialdehyde level and suppression of antioxidase activity in the pFRG region of neonatal rats induced by prenatal CSE. Furthermore, NaHS prevented the downregulation of the expression of antioxidases and Nrf2 in the pFRG region of neonatal rats with prenatal CSE. These results suggest that H₂S can protect the pFRG of neonatal rats against prenatal CSE-induced injury via an antioxidative effect.     

Heat shock protein 90 mediates cytoprotection by H₂S against chemical hypoxia-induced injury in PC12 cells

1. Increasing evidence indicates that hydrogen sulphide (H₂S) may serve as an important biological cytoprotective agent. Heat shock protein (Hsp) 90 can attenuate stress‐induced injury. However, whether Hsp90 mediates the cytoprotective effect of H₂S against chemical hypoxia‐induced injury in PC12 cells is not known. 2. In the present study, CoCl₂ (a chemical hypoxia mimetic) was used to treat PC12 cells to create a model of chemical hypoxia. To explore the role of Hsp90 in the cytoprotection afforded by H₂S against chemical hypoxia‐induced injury, 2 μmol/L 17‐allylaminogeldanamycin (17‐AAG), a selective inhibitor of Hsp90, was administered for 30 min prior to preconditioning with 400 μmol/L NaHS, followed by chemical hypoxia. 3. Cobalt chloride reduced cell viability (by 52.7 ± 1.5%), increased PC12 cell apoptosis (by 42.1 ± 1.5%), induced reactive oxygen species (ROS) by 3.79% compared with control and induced the dissipation of mitochondrial membrane potential (MMP) by 2.56% compared with control. 4. Pretreatment of PC12 cells with 100–400 μmol/L sodium hydrosulphide (NaHS), an H₂S donor, for 3 h prior to exposure to 600 μmol/L CoCl₂ provided significant, concentration‐dependant protection to PC12 cells against CoCl₂‐induced cytotoxicity. Specifically, pretreatment of PC12 cells with 400 μmol/L NaHS decreased apoptosis to 16.77 ± 1.77% and blocked the CoCl₂‐induced increase in ROS production and loss of MMP. 5. At 400 μmol/L, NaHS upregulated Hsp90 in a time‐dependant manner (over the period 0–180 min). In addition to its effects on Hsp90 expression, NaHS pretreatment of PC12 cells augmented the overexpression of Hsp90 induced by 600 μmol/L CoCl₂ by 1.38‐fold (P < 0.01). 6. Treatment of PC12 cells with 2 μmol/L 17‐AAG for 30 min prior to NaHS pretreatment blocked the overexpression of Hsp90 induced by NaHS preconditioning, as evidenced by decreased cell viability (by 54.2 + 1.2%; P < 0.01), increased PC12 cell apoptosis (by 36.6 ± 1.2%; P < 0.01) and increasing ROS production. 7. The findings of the present study provide novel evidence that Hsp90 mediates H₂S‐induced neuroprotection against chemical hypoxia‐induced injury via anti‐oxidant and anti‐apoptotic effects.     

凉膈散对肠缺血再灌注损伤大鼠肠道的保护作用

目的:观察凉膈散对大鼠缺血再灌注(I/R)损伤肠黏膜的保护作用.方法:健康Wistar大鼠168只,随机分为正常组、假手术组、模型组、凉膈散治疗组和凉隔散防治组,其中正常组8只,其他4组各40只.正常组不予任何处理,假手术组只分离不夹闭肠系膜上动脉,其余3组通过夹闭肠系膜上动脉建立大鼠小肠I/R模型,根据缺血45min后再灌注3、12、24、48和72h5个时相点义分为5组,每组8只大鼠.测定各组5个时点动物小肠黏膜病理损伤Chiu氏评分、门静脉血浆D-乳酸值、小肠组织匀浆丙二醛(MDA)含量和超氧化物歧化酶(SOD)活力、肠黏膜细胞凋亡指数及Bax表达水平.结果:模型组动物肠黏膜结构破坏明显,Chiu氏评分、血浆D-乳酸值明显升高.小肠匀浆MDA含量升高、SOD活力降低,肠黏膜细胞凋亡指数及Bax表达水平升高.凉膈散干预后,可减轻小肠黏膜病理损伤程度、与模型组比较,除3h外,门静脉血浆D-乳酸值下降,小肠组织匀浆MDA含量降低和SOD活力升高、肠黏膜细胞凋亡指数及Bax表达水平均下降.结论:I/R损伤可破坏肠黏膜屏障功能,凉膈散可通过减少机体氧自由基的生成而保护肠黏膜.     

Palmatine from Coptidis rhizoma reduces ischemia–reperfusion-mediated acute myocardial injury in the rat

The aim of the present study was to evaluate the protective effect of palmatine, one of active ingredients of Coptidis rhizoma, against myocardial ischemia–reperfusion (I/R) injury is due to its antioxidant and anti-inflammatory action. Adult male rats were subjected to 30 min of ischemia and 6 or 24 h of reperfusion. Rats were randomized to receive vehicle or palmatine 1 h before reperfusion. Infarct size, myocardial function, and the antioxidant enzyme activity, such as malonaldehyde (MDA), lactate dehydrogenase (LDH), creatine phosphokinase (CK), superoxide dismutase (SOD) and catalase (CAT) were measured. Palmatine significantly improved I/R-induced myocardial dysfunction by increasing the values of the first derivative (±dp/dt) of left ventricular pressure and decreased infarct size by 50% (P < 0.01 versus vehicle). As expected, palmatine markedly inhibited the increase of LDH, CK, and MDA contents in I/R rat serum, and it also significantly inhibited the decline of the activity of SOD and CAT in I/R cardiac tissues. In addition, COX-2 and iNOS expression in I/R myocardium was significantly reduced. Interestingly, plamatine increased heme oxygenase (HO)-1 induction in human aortic endothelial cells. We concluded that palmatine protects hearts from I/R injury in rats possibly by reducing oxidative stress and modulating inflammatory mediators.     

右美托咪定对心肌缺血大鼠超氧化物歧化酶、丙二醛及髓过氧化物酶的影响

目的 观察右美托咪定对心肌缺血再灌注大鼠超氧化物歧化酶(SOD)、丙二醛(MDA)及髓过氧化物酶(MPO)水平的影响.方法 健康成年雄性SD大鼠50只,体质量250～300 g,随机均分成5组:假手术组(S组),心肌缺血再灌注组(I/R组),右美托咪定组(Dex组),线粒体ATP敏感性钾离子通道(mitoKATP)阻断剂5-羟葵酸组(5-HD组),5-羟葵酸+右美托咪定组(5-HD+Dex组).建立大鼠心肌缺血再灌注损伤模型,S组仅仅穿线不结扎;Dex组于结扎前经尾静脉输注负荷剂量1μg·kg-1的右美托咪定,注入时间10 min,然后以0.5μg·kg-1·h-1的速率维持15 min;5-HD组于结扎前经尾静脉输注5 mg·kg-1的5-HD,注入时间5 min;5-HD+Dex组于结扎前先输注5-HD(同5-HD组),再输注右美托咪定(同Dex组).于再灌注结束后,取大鼠心脏,测定心肌组织SOD、MDA和MPO的水平,并检测心肌梗死体积.结果 与S组比较,其余各组SOD水平降低,MDA及MPO水平升高,心肌梗死体积增大(P<0.05);与I/R组比较,Dex组SOD水平升高,MDA及MPO水平降低,心肌梗死体积减小(P<0.05);与Dex组比较,5-HD+Dex组SOD水平降低,MDA及MPO水平升高,心肌梗死体积增大(P<0.05).结论 右美托咪定可减轻大鼠心肌缺血再灌注损伤,其机制可能与mitoKATP的开放有关.     

红景天苷对大鼠局灶性脑缺血/再灌注损伤的保护作用

目的研究红景天苷对大鼠局灶性脑缺血/再灌注损伤的保护作用。方法制作大鼠大脑中动脉闭塞(middlecerebral artery occlusion,MCAO)模型,观察大鼠行为学改变;取大脑并用红四氮唑(tetrazolium chloride,TTC)染色后测定梗死百分比和含水量;进行大脑组织学的检查以及制作脑匀浆测定SOD、MDA、GSH、Na+,K+-ATP酶、Ca2+-ATP酶、LD和NO的含量。结果红景天苷高、中、低剂量组(24、12、6mg.kg-1)均能使动物的行为学评分、脑梗死百分比、脑含水量明显降低;改善脑组织学损伤;并能够明显增加SOD、GSH的含量并降低MDA、NO、LD的含量,其中24、12mg.kg-1组还能明显提高缺血/再灌注后脑匀浆内Na+,K+-ATP酶、Ca2+-ATP酶的活力。结论红景天苷对脑缺血/再灌注有一定的保护作用。     

褪黑素对大鼠全脑缺血-再灌注损伤及P53蛋白表达的影响

探讨了褪黑素 (MT)神经保护作用的机理 .采用大鼠“四动脉结扎法”制成全脑缺血 (2 0min) 再灌注模型 .①于再灌注开始时ipMT 2 .5或 10mg·kg- 1,于再灌注 1h断头取脑 ,检测谷胱甘肽过氧化物酶 (GSH Px) ,超氧化物歧化酶 (SOD)的活性以及丙二醛 (MDA)的含量 ;②于再灌注后 0 ,1,2 ,6h重复ipMT 2 .5或 10mg·kg- 1共 4次 ,再灌后 2 4h取脑组织 ,应用免疫组化方法检测海马CA1区神经细胞内P5 3蛋白的表达 .结果可见 ,MT两个剂量均可提高大鼠全脑缺血 再灌注后脑组织中GSH Px及SOD的活性 ,降低MDA含量 ,均可抑制海马CA1区损伤蛋白P5 3的表达 .结果表明 ,MT对缺血 再灌注后脑损伤的保护作用至少与以下两方面有关 :①增强抗氧化酶GSH Px ,SOD的活性 ,减少脂质过氧化损伤 ;②抑制缺血 再灌后P5 3蛋白的表达     

Aliskiren protects against myocardial ischaemia‐reperfusion injury via an endothelial nitric oxide synthase dependent manner

Aliskiren, a direct renin inhibitor, has shown potent ability to attenuate hypertension. Our previous research has found that aliskiren protected against myocardial ischaemia‐reperfusion (I/R) injury and enhanced phosphorylation of endothelial nitric oxide synthase (eNOS) in spontaneously hypertensive rats. However, whether the cardioprotective effect of aliskiren against myocardial I/R injury was eNOS‐dependent is unknown. In the present study, 12‐week‐old male eNOS knockout (eNOS^?/?) and wild‐type C57BL/6J mice (WT) were orally administrated with the dose of 50 mg/kg per day of aliskiren. After a 4‐week treatment, aliskiren decreased blood pressure in eNOS^?/? mice, and reduced renin‐angiotension II levels in both eNOS^?/? and WT mice. Aliskiren also improved left ventricular ejection fraction (EF) and fractional shortening (FS), decreased myocardial infarct size, reduced creatine kinase (CK) and lactate dehydrogenase (LDH) activity in plasma, attenuated dihydroethidium (DHE) fluorescence and levels of malondialdehyde (MDA), enhanced superoxide dismutase (SOD) activity and total antioxidant capacity (T‐AOC) in myocardium, increased SOD and thioredoxin (Trx) proteins expression in WT mice subjected to 30 minutes of ischaemia followed by reperfusion for 24 hours. However, aliskiren failed to restore all of the above indices in eNOS^?/? mice subjected to the same I/R injury. Our study indicated that aliskiren protected against myocardial I/R injury via an eNOS dependent manner.     

Caffeic acid phenethyl ester (CAPE) protects rat skeletal muscle against ischemia-reperfusion-induced oxidative stress

Oxygen-derived free radicals have been implicated in the pathogenesis of skeletal muscle injury after ischemia-reperfusion. Caffeic acid phenethyl ester, an active component of propolis extract, exhibits antioxidant properties. The aim of this study was to assess the effects of caffeic acid phenethyl ester (CAPE) and alpha-tocopherol (vit E) on ischemia/reperfusion (I/R) injury in a rat hind limb ischemia/reperfusion model. For this purpose, ischemia was induced in anesthetized rats by unilateral (right) femoral artery clipping for 2 h followed by 2 h of reperfusion. Four groups were studied: sham, I/R, I/R+CAPE and I/R+vit E. Drugs were administered intraperitoneally after 1 h of ischemia and I/R rats received saline vehicle. After 2 h of reperfusion, venous blood was sampled and the right gastrocnemius muscle was harvested. Plasma and tissue were assayed for malondialdehyde (MDA), superoxide dismutase (SOD) and nitric oxide (NO) metabolites. Tissue was also assayed for catalase (CAT) activity. Both tissue and plasma NO levels, MDA levels, SOD activities was significantly increased in I/R groups compared to control groups. The two treated groups showed decreased MDA and NO in both muscle and plasma compared to the I/R group. No differences were noted in muscle tissue SOD in three I/R groups, but SOD activity were increased in the plasma of I/R+CAPE and I/R+vit E groups compared with I/R group. Whereas tissue CAT activity was not changed among groups. Our results indicate that CAPE has antioxidant properties similar to those of vit E in this model and may attenuate the harmful effects of hind limb I/R in skeletal muscle.