川芎嗪对兔肺缺血/再灌注损伤时血红素氧合酶-1表达与活性的影响

目的:探讨川芎嗪注射液对兔肺缺血/再灌注损伤时血红素氧合酶-1(HO-1)表达与活性的影响.方法:采用在体兔单肺原位缺血/再灌注损伤模型.实验兔20只,随机均分为肺缺血-再灌注损伤组(模型组)和川芎嗪注射液治疗组(川芎嗪组).用免疫组化、原位杂交方法观察HO-1在兔肺组织中的表达变化;测定肺组织湿干重比(W/D)及肺泡损伤数(IAR);电镜观察肺组织超微结构的改变.结果:HO-1在模型组、川芎嗪组肺血管内皮、部分血管平滑肌、外膜层及部分气道上皮均有阳性表达,免疫组化(原位杂交)的平均吸光度值分别为0.168±0.016(0.148±0.013)、0.186±0.014(0.158±0.012).川芎嗪组HO-1的表达水平明显高于模型组(P＜0.01),W/D、IAR值显著低于模型组(P＜0.01),肺组织形态学异常改变轻于模型组.结论:川芎嗪注射液可通过提高肺组织HO-1的表达水平,对肺缺血/再灌注损伤发挥积极的保护作用.     

缺血预处理对缺血/再灌注离体心脏的保护作用

目的：探讨连续多次短暂缺血预处理对缺血/再灌注损伤心肌的保护作用及机制。方法：采用大鼠离体心脏Lan-gendorff灌流模型,观察缺血预处理对心肌缺血/再灌注后不同时间点冠脉流出液中AST、CPK、UDH及冠脉流量,心肌组织中SOD、LPO以及再灌注性心律失常的影响。结果：缺血预处理可以减少缺血/再灌注损伤的心肌冠脉流出液中AST、CPK、LDH的含量,提高心肌SOD活性,降低LPO水平,并且抑制再灌注性心律失常的发生,提高再灌注期间的冠脉流量。结论：缺血预处理对心肌缺血/再灌注损伤具有一定保护作用。     

黑木耳多糖对抗离体心脏缺血/再灌注损伤的研究

目的:探讨黑木耳多糖(AAP)对离体大鼠心脏缺血/再灌注(I/R)损伤的防护作用及其机制。方法:健康雄性SD大鼠灌胃黑木耳多糖(50,100,200mg/(kg.d))4周后,采用离体心脏Langendorff灌流方法,全心停灌30min,复灌120min建立I/R模型。测定左心室动力学指标和再灌注各时间点冠脉流出液中乳酸脱氢酶(LDH)含量;实验结束测定心肌组织甲月赞(formazan)、丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性的变化。结果:与单纯I/R组相比,AAP预处理明显提高心肌细胞的formazan含量,降低再灌注期间冠脉流出液中LDH含量,明显增强左室发展压、左心室内压最大上升速率和心率与发展压乘积的恢复,缓解冠脉流量的减少;高剂量AAP改善I/R心肌功能的作用要好于丹参预处理(4ml/(kg.d),gastricperfusion)组。中剂量AAP(100mg/(kg.d))预处理4周后明显抑制I/R心肌MDA的增加和SOD活性的减弱(P0.01),其效果要好于丹参阳性对照组。结论:在大鼠离体心脏灌流模型上,黑木耳多糖预处理具有抗心脏I/R损伤的作用,这种保护作用可能与其增加心肌SOD活性,减少脂质过氧化损伤有关。     

mTOR and Beclin1: Two key autophagy-related molecules and their roles in myocardial ischemia/reperfusion injury

Autophagy is the general term of lysosomal degradation of substances in cells, which is considered the key to maintaining the normal structure and function of the heart. It also has a correlation with several heart diseases, in particular, myocardial ischemia/reperfusion (I/R) injury. At the stage of myocardial ischemia, autophagy degrades nonfunctional cytoplasmic proteins providing the critical nutrients for the critical life activities, thereby suppressing cell apoptosis and necrosis. However, autophagy is likely to affect the heart negatively in the reperfusion stage. Mammalian target of rapamycin (mTOR) and Beclin1 are two vital autophagy-related molecules in myocardial I/R injury playing significant roles in different stages. In the ischemia stage, mTOR plays its roles through AMPK/mTOR and phosphoinositide 3-kinase/Akt/mTOR pathway, whereas Beclin1 plays its roles through its upregulation in the reperfusion stage. A possible interaction between mTOR and Beclin1 has been reported recently, and further studies need to be done to find the underlying interaction between the two molecules in myocardial I/R injury     

Inhibition of cathepsin S attenuates myocardial ischemia/reperfusion injury by suppressing inflammation and apoptosis

Myocardial ischemia/reperfusion (I/R) injury leads to high mortality and morbidity due to the incomplete understanding of the underlying mechanism and the consequent lack of effective therapy. The present study revealed and validated key candidate genes in relation to inflammation and apoptosis pathways underlying myocardial I/R injury. Cathepsin S was identified as the top hub protein based on the protein–protein interaction analysis, and, thus, its role during myocardial I/R injury was further investigated. Myocardial I/R in mice resulted in significantly increased levels of myocardial injury biomarkers (cardiac troponin I, lactic dehydrogenase, and creatinine kinase‐MB) and inflammatory cytokines (interleukin‐1β [IL‐1β], IL‐6, and tumor necrosis factor‐α), elevated apoptosis rate, and upregulated protein expression of cleaved caspase‐8, cleaved caspase‐3, and cleaved poly ADP‐ribose polymerase. These abovementioned changes were blocked by two different selective cathepsin S inhibitors, LY3000328 or MIV‐247. Moreover, Kaplan–Meier survival plot showed that cathepsin S inhibition improved 21‐day survival rate following myocardial I/R injury. This study demonstrated that the inhibition of cathepsin S alleviated myocardial I/R‐induced injury by suppressing inflammation and apoptosis, which may be used in clinical applications of cardioprotection.     

血红素氧合酶-1在离体大鼠心肌缺血预适应中的作用

目的:分别观察给予HO-1诱导剂和抑制剂对心肌相对缺血再灌注损伤和缺血预适应的影响,探讨HO-1在缺血预适应中的作用.方法:实验动物随机分为对照组(CN)、缺血/再灌损伤组(I/R)、缺血预适应 缺血/再灌损伤组(PC)、HO-1诱导剂 缺血/再灌损伤组(HM)、HO-1抑制剂 缺血预适应组(ZP).心肌缺血/再灌损伤采用相对缺血/再灌损伤模型,缺血预适应则为相对缺血5min恢复5min,反复2次.测定心功能、MDA及HO-1活性变化.结果:HM组HO-1活性升高,心功能恢复率均显著高于IR组(P＜0.01),MDA含量显著低于IR组(P＜0.05).ZP组活性降低,心功能恢复率显著低于PC组(P＜0.05),MDA含量显著高于PC组(P＜0 05).结论:HO-1是缺血预适应释放的内源性活性物质之一.     

大鼠肢体缺血/再灌注后肝脏 HO-1表达的变化及其意义

目的:探讨肢体缺血/再灌注(I/R)致肝脏损伤时肝组织诱导型血红素氧合酶(HO-1)表达的变化及其意义.方法:夹闭大鼠双侧股动脉根部4 h、开放2～24 h,制备肢体I/R模型.RT-PCR检测肝组织HO-1 mRNA表达的变化,免疫组化染色法观察HO-1蛋白在肝内的生成与分布.对肢体I/R大鼠应用锌原卟啉抑制其体内HO-1活性后,光镜观察其肝组织的病理变化.结果:肢体I/R后肝组织HO-1 mRNA的表达水平显著高于各对照组,再灌12 h表达至峰值,至再灌24 h仍显著高于各对照组(P＜0.01).肢体I/R组肝组织内出现大量弥散分布的HO-1阳性肝细胞,抑制HO-1活性,使肢体I/R组肝组织损伤明显加重.结论:肢体I/R损伤可诱导肝细胞HO-1基因表达上调,所诱生的HO-1对肝细胞具有保护效应.     

Protection against in vivo focal myocardial ischemia/reperfusion injury-induced arrhythmias and apoptosis by Hesperidin

Among the heart diseases, ischemia and reperfusion (I/R) induced arrhythmias contribute to episodes of sudden death. Cardiac arrhythmias during ischemia reperfusion are believed to be related to oxidative stress. Therefore, the aim of this study was to examine whether treatment with Hesperidin alleviates arrhythmias and infarct size in experimentally-induced myocardial I/R injury using an in vivo rat model. In this study haemodynamics parameters, markers of inflammation, biomarkers of oxidative stress and tissue nitrite level and infarct size of the heart were estimated in various groups. I/R showed a significant decrease in tissue nitrite and antioxidant level and significant increase in arrhythmias, inflammation and myocardial cell apoptosis. Treatment with Hesperidin showed a significant increase in tissue nitrite, antioxidant level and reduction in inflammation, arrhythmias and apoptosis. In conclusion, the protecting effect of Hesperidin in I/R induced arrhythmias is due to reduction in inflammation and oxidative stress.     

雌激素对去卵巢大鼠离体心脏缺血／再灌注损伤的保护作用

目的：探讨雌激素对去卵巢大鼠离体心脏缺血／再灌注损伤的保护作用。方法：成年SD雌鼠,随机分为假手术组（Sham）,双侧卵巢切除组（Ovx）和双侧卵巢切除后补充17β-雌二醇组（Ovx＋E2）。各组离体心脏再随机分为不同时间的缺血再灌注亚组。测量的指标包括冠脉流出液中LDH及CK含量、心室肌细胞存活率及产率、基础状态和异丙肾上腺素（ISO）刺激状态下收缩幅度。结果：30min缺血及其各复灌纽均显著增加冠脉流出液中LDH、CK的释放量。Ovx组LDH、CK漏出在30min缺血及再灌注条件下,显著高于正常灌注组,而Ovx＋E2组可减轻心肌损伤,减少LDH、CK的释放。10min和20min缺血对心肌细胞存活率、产率及冠脉流出液中LDH、CK含量影响均不明显。Sham、Ovx、Ovx＋E2各组心肌细胞基础收缩幅度在正常和10minⅠ＋30minR灌注条件下无显著差异。Ovx显著增加其他各组心肌细胞基础收缩和ISO刺激收缩幅度,Ovx＋E2可使其降至Sham水平。结论：雌激素对去卵巢大鼠心肌缺血／再灌注损伤具有保护作用。     

Hydrogen-rich saline protects against intestinal ischemia/reperfusion injury in rats

Hydrogen gas was reported to reduce reactive oxygen species and alleviate cerebral, myocardial and hepatic ischemia/reperfusion (I/R) injuries. This paper studied the effect of hydrogen-rich saline, which was easier for clinical application, on the intestinal I/R injury. Model of intestinal I/R injury was induced in male Sprague-Dawley rats. Physiological saline, hydrogen-rich saline or nitrogen-rich saline (5 ml/kg) was administered via intravenous infusion at 10 min before reperfusion, respectively. The intestine damage was detected microscopically and was assessed by Chiu score system after I/R injury. In addition, serum DAO activity, TNF-α, IL-1β and IL-6 levels, tissue MDA, protein carbonyl and MPO activity were all increased significantly by I/R injury. Hydrogen-rich saline reduced these markers and relieved morphological intestinal injury, while no significant reduction was observed in the nitrogen-rich saline-treated animals. In conclusion, hydrogen-rich saline protected the small intestine against I/R injury, possibly by reduction of inflammation and oxidative stress.     

心肌缺血预适应循环血中微囊泡对大鼠心肌I/R损伤的作用

目的：研究心肌缺血预适应（IPC）大鼠循环血中微囊泡（MVs）对大鼠在体心肌缺血/再灌注（I/R）损伤的作用及相关机制。方法：反复短暂结扎/松开大鼠冠状动脉左前降支建立大鼠IPC模型,自腹主动脉取血,超速离心法分离循环血中的IPC-MVs,并对其进行流式鉴定。建立在体大鼠心肌I/R模型,股静脉注射IPC-MVs 7 mg/kg。HE染色观察心肌形态学变化,TTC染色检测心肌梗死范围,TUNEL染色检测心肌细胞凋亡率。比色法测定血清乳酸脱氢酶（LDH）活力,分光光度法测定心肌组织caspase 3活力,Western blot法检测心肌组织Bcl-2、Bax蛋白表达水平。结果：流式细胞术检测IPC-MVs浓度为4380±745个/μl。与I/R组比较,IPC-MVs能够减轻I/R大鼠心肌组织损伤,缩小心肌梗死范围（P<0.01）,减少心肌细胞凋亡数量（P<0.01）,明显降低血清LDH活力（P<0.01）,降低心肌组织caspase 3活力（P<0.01）,升高Bcl-2蛋白表达（P<0.01）,降低Bax蛋白表达（P<0.01）,升高Bcl-2/Bax比值（P<0.01）。结论：IPC-MVs显著减轻大鼠在体心肌I/R损伤,通过上调心肌组织中Bcl-2的蛋白表达,下调Bax的蛋白表达,升高Bcl-2/Bax比值,降低caspase 3活力而发挥心肌保护作用。     

Prior induction of heme oxygenase-1 with glutathione depletor ameliorates the renal ischemia and reperfusion injury in the rat

Heme oxygenase (HO)-1 catalyzes the rate-limiting step in heme degradation releasing iron, carbon monoxide, and biliverdin. Induction of HO-1 occurs as an adaptive and protective response to oxidative stress. Ischemia and reperfusion (IR) injury seems to be mainly caused by the oxidative stress. In this study, we have examined whether prior induction of HO-1 with buthionine sulfoximine (BSO), a glutathione (GSH) depletor, affects the subsequent renal IR injury. BSO (2 mmol/kg body weight) was administered intraperitoneally into rats, the levels of HO-1 protein increased within 4 h after the injection. When BSO was administered into rats at 5 h prior to the renal 45 min of ischemia, the renal IR injury was assessed by determining the levels of blood urea nitrogen and serum creatinine, markers for renal injury, after 24 h of reperfusion. The renal injury was significantly improved as compared to the rats treated with IR alone. Administration of zinc-protoporphyrin IX, an inhibitor of HO activity, reduced the efficacy of BSO pretreatment on the renal IR injury. Our findings suggest that the prior induction of HO-1 ameliorates the subsequent renal IR injury.     

蒙药绍沙-7味丸防治大鼠心肌缺血/再灌注损伤的作用

目的:探讨蒙药绍沙-7味丸对心肌缺血/再灌注损伤大鼠的防治作用及机制.方法:60只大鼠随机分成6组:假手术组、模型组、蒙药绍沙-7味丸低、中、高剂量组以及阳性药对照组,每组10只;蒙药绍沙-7味丸低、中、高剂量组分别灌胃0.4 g/kg、0.8 g/kg、1.6 g/kg蒙药绍沙-7味丸,阳性药对照组灌胃0.3 g/k...     

Free fatty acid metabolism during myocardial ischemia and reperfusion

Long chain free fatty acids (FFA) are the preferred metabolic substrates of myocardium under aerobic conditions. However, under ischemic conditions long chain FFA have been shown to be harmful both clinically and experimentally. Serum levels of free fatty acids frequently are elevated in patients with myocardial ischemia. The proposed mechanisms of the detrimental effects of free fatty acids include: (1) accumulation of toxic intermediates of fatty acid metabolism, such as long chain acyl-CoA thioesters and long chain acylcarnitines, (2) inhibition of glucose utilization, particularly glycolysis, during ischemia and/or reperfusion, and (3) uncoupling of oxidative metabolism from electron transfer. The relative importance of these mechanisms remains controversial. The primary site of FFA-induced injury appears to be the sarcolemmal and intracellular membranes and their associated enzymes. Inhibitors of free fatty acid metabolism have been shown experimentally to decrease the size of myocardial infarction and lessen postischemic cardiac dysfunction in animal models of regional and global ischemia. The mechanism by which FFA inhibitors improve cardiac function in the postischemic heart is controversial. Whether the effects are dependent on decreased levels of long chain intermediates and/or enhancement of glucose utilization is under investigation. Manipulation of myocardial fatty acid metabolism may prove beneficial in the treatment of myocardial ischemia, particularly during situations of controlled ischemia and reperfusion, such as percutaneous transluminal coronary angioplasty and coronary artery bypass grafting. (Mol Cell Biochem 166: 85-94, 1997)     

Targeting autophagy in cardiac ischemia/reperfusion injury: A novel therapeutic strategy

Acute myocardial infarction (AMI) is one of the leading causes of morbidity worldwide. Myocardial reperfusion is known as an effective therapeutic choice against AMI. However, reperfusion of blood flow induces ischemia/reperfusion (I/R) injury through different complex processes including ion accumulation, disruption of mitochondrial membrane potential, the formation of reactive oxygen species, and so forth. One of the processes that gets activated in response to I/R injury is autophagy. Indeed, autophagy acts as a “double-edged sword” in the pathology of myocardial I/R injury and there is a controversy about autophagy being beneficial or detrimental. On the basis of the autophagy effect and regulation on myocardial I/R injury, many studies targeted it as a therapeutic strategy. In this review, we discuss the role of autophagy in I/R injury and its targeting as a therapeutic strategy.     

Proteasome inhibition attenuates lung injury induced by intestinal ischemia reperfusion in rats

The aim of this study is to investigate the role of proteasome in the pathogenesis of lung injury induced by intestinal ischemia/reperfusion (I/R) by examining the effect of the proteasome inhibitor lactacystin on neutrophil infiltration, intracellular adhesion molecule-1 (ICAM-1) expression and nuclear factor kappa B (NF-κB) activation. Thirty-two Wistar rats were divided into (1) control, (2) intestinal I/R, (3) 0.2 mg/kg lactacystin pretreated, and (4) 0.6 mg/kg lactacystin pretreated groups (n = 8). Injuries in lung and intestine were induced by intestinal I/R, and were characterized by histological edema, hemorrhage and infiltration of inflammatory cells. The results showed a significant increase in serum creatine kinase B (CK-B) and lung water content in intestine and lung injuries. As compared with the control group, the myeloperoxidase (MPO) activity in intestine and lung as well as the serum TNF-α level increased significantly in intestinal I/R group. Simultaneously, expression of ICAM-1 and NF-κB p65 was also observed in the I/R group. Pre-treatment with lactacystin markedly reduced 20S proteasome activity in circulating white blood cells and ameliorated intestine and lung injuries. These results demonstrated that the proteasome participates in the pathogenesis of lung injury induced by intestinal I/R. Lactacystin as a proteasome inhibitor can prevent this kind of injury by decreasing ICAM-1 and TNF-α production via the inhibition of NF-κB activation.     

Resveratrol,novel application by preconditioning to attenuate myocardial ischemia/reperfusion injury in mice through regulate AMPK pathway and autophagy level

Myocardial ischemia/reperfusion injury (MI/RI) is the main cause of deaths in the worldwide, leading to severe cardiac dysfunction. Resveratrol (RSV) is a polyphenol plant‐derived compound. Our study aimed to elucidate the underlying molecular mechanism of preconditioning RSV in protecting against MI/RI. Mice were ligated and re‐perfused by the left anterior descending branch with or without RSV (30 mg/kg·ip) for 7 days. Firstly, we found that RSV pretreatment significantly alleviated myocardial infarct size, improved cardiac function and decreased oxidative stress. Furthermore, RSV activated p‐AMPK and SIRT1, ameliorated inflammation including the level of TNF‐α and IL‐1β, and promoting autophagy level. Moreover, neonatal rat ventricular myocytes (NRVMs) and H9c2 cells with knockdown the expression of AMPK, SIRT1 or FOXO1 were used to uncover the underlying molecular mechanism for the cardio‐protection of RSV. In NRVMs, RSV increased cellular viability, decreased LDH release and reduced oxidative stress. Importantly, Compound C(CpC) and EX527 reversed the effect of RSV against MI/RI in vivo and in vitro and counteracted the autophagy level induced by RSV. Together, our study indicated that RSV could alleviate oxidative stress in cardiomyocytes through activating AMPK/SIRT1‐FOXO1 signallingpathway and enhanced autophagy level, thus presenting high potential protection on MI/RI.     

肠缺血/再灌注损伤后白介素1-β水平与磷脂酶A2激活的关系

为了探讨肠缺血/再灌注损伤后IL-1β基因表达和蛋白含量变化与磷脂酶A2抑制之间的关系,采用大鼠肠缺血/再灌注损伤模型,在对照组,损伤组和磷脂酶A2抑制剂处理组动物中收集血清,肺灌洗液,腹腔灌洗液及全身重要脏器组织样品,采用放射免疫法测定IL-1β含量,并且RT-PCR法测定肺组织中IL-1β和Ⅱ型PLA2基因表达,结果表明,损伤后6h血清中IL-1β含量明显高于对照组;损伤后1和3h,腹腔注保IL-1β也明显高于对照组;损伤后肝组织中IL-1β水平有明显增加,而肺,肾、肠组织中IL-1β没有明显变化。损伤后肺灌洗液中IL-1β也明显高于对照组水平,肺组织中IL-1βmRNA表达增加,而Ⅱ型PLA2mRNA在损伤后表达反而有所下降,采用磷脂酶A2抑制剂氯喹,环氧化物酶抑制剂消炎痛,血小板活化因子受体阻断剂SR27417后,IL-1β蛋白和基因表达有不同的改变,提示肠缺血/再灌注损伤后一定时间内,肝内IL-1βmRNA表达和血中IL-1β水平明显增高,但是否与磷脂酶A2激活或其代谢产物的释放有关尚需进一步证明。     

Hydrogen-rich saline reduces lung injury induced by intestinal ischemia/reperfusion in rats

Objective. Hydrogen has been reported to selectively reduce the hydroxyl radical, the most cytotoxic of reactive oxygen species. In this study we investigated the effects of hydrogen-rich saline on the prevention of lung injury induced by intestinal ischemia/reperfusion (I/R) in rats. Methods. Male Sprague-Dawley rats (n = 30, 200-220 g) were divided randomly into three experimental groups: sham operated, intestinal I/R plus saline treatment (5 ml/kg, i.v.), and intestinal I/R plus hydrogen-rich saline treatment (5 ml/kg, i.v.) groups. Intestinal I/R was produced by 90 min of intestinal ischemia followed by a 4 h of reperfusion. Results. Hydrogen-rich saline treatment decreased the neutrophil infiltration, the lipid membrane peroxidation, NF-κB activation and the pro-inflammatory cytokine interleukin IL-1β and TNF-α in the lung tissues compared with those in saline-treated rat. Conclusion. Hydrogen-rich saline attenuates lung injury induced by intestinal I/R.