茶多酚对大鼠肾缺血再灌注损伤保护作用实验研究

目的探讨茶多酚(Tea polyphenols TP)预处理对大鼠肾缺血再灌注损伤的保护作用及其机制。方法建立大鼠肾缺血再灌注损伤(renal ischemia reperfusion injury RIRI)模型。选用健康SD大鼠42只,随机分为3组:假手术组、单纯肾缺血再灌注损伤组,茶多酚预处理组。于肾缺血再灌注(renal ischemia reperfusion RIR)开始时刻、RIR后2h、RIR后24h分别检测血清肌酐(SCr),血清超氧化物岐化酶(SOD)、血清丙二醛(MDA)、肾组织SOD、肾组织MDA及观察肾组织的病理变化。结果茶多酚预处理组与假手术组相比较,RIRI组SCr水平升高(P<0.05),肾组织及血清中的SOD降低及MDA水平增加(P<0.05)。而茶多酚预处理组SCr、血清MDA和肾组织MDA均比单纯RIRI组低(P<0.05),血清SOD水平及肾组织SOD水平升高(P<0.05)。结论在肾脏缺血再灌注损伤过程中,茶多酚能起到对肾脏的保护作用。     

核转录因子NF-κB与肾脏缺血-再灌注损伤

核转录因子κB(NF-κB)普遍存在于真核生物细胞内,在免疫反应、炎症反应、细胞凋亡、缺血-再灌注损伤等病理生理改变过程中起着重要的调控作用。NF-κB在肾脏缺血-灌注损伤中的起着重要作用,本文就这方面的研究进展进行综述。     

西洋参皂苷对缺血-再灌注诱导乳鼠心肌细胞凋亡及钙浓度的影响

目的探讨西洋参皂苷(Panax quinquefolius saponin,PQS)对缺血-再灌注(ischemia/reperfusion,I/R)诱导乳鼠心肌细胞凋亡及钙浓度的影响。方法将原代培养的心肌细胞分为正常对照组(不做任何处理)、I/R组(心肌细胞经缺氧、无血清孵育2 h,再复氧、复血清培养24、48 h,以模拟心肌I/R损伤)和西洋参总皂苷干预组(PQS+I/R,细胞再灌注时分别加入5、10、20、40μg/ml PQS),采用台盼蓝染色法检测各组心肌细胞的活性;流式细胞术检测心肌细胞的凋亡率;激光扫描共聚焦显微镜检测心肌细胞内游离钙的变化。结果与I/R组比较,10、20、40μg/ml PQS+I/R组心肌细胞活性显著增加(P0.01),心肌细胞凋亡率显著降低(P0.05);20μg/ml的PQS可降低心肌细胞的钙负载。结论 PQS可显著减少I/R诱导的心肌细胞凋亡,并减轻心肌细胞钙超载的发生,这可能是PQS抑制I/R心肌细胞凋亡的机制之一。     

姜黄素对小鼠心肌缺血再灌注损伤的保护作用及其与Toll样受体4/核因子-κB信号通路的相关性

目的探讨姜黄素对小鼠心肌缺血再灌注损伤(myocardial ischemia-reperfusion injury,MIRI)的保护作用及其与Toll样受体4(Toll-like receptor 4,TLR4)/核因子-κB(nuclear factor kappa-light-chain-enhancer of activated B cells,NF-κB)信号通路的相关性。方法取健康C57BL/6小鼠,采用随机区组法分为假手术组(Sham组)、MIRI组及姜黄素预处理的MIRI组(Cur组):使用丝线暂时阻断小鼠冠状动脉前降支(left anterior descending,LAD)血流30 min,再灌注4 h,建立小鼠MIRI模型;假手术组接受相同的手术过程,但未阻断LAD;Cur组在缺血前30 min腹腔注射姜黄素(100 mg/kg)。采用伊文思蓝和氯化三苯基四氮唑(2,3,5-triphenyltetrazolium chloride,TTC)染色评估小鼠心肌梗死面积;电化学发光法检测小鼠血清肌钙蛋白(cardiac troponin T,cTnT)水平;RT-PCR法检测小鼠心肌组织TLR4及肿瘤坏死因子-α(tumor nectosis factor-alpha,TNF-α,)mRNA水平;Western blot法检测小鼠心肌组织NF-κB蛋白表达水平;ELISA法检测小鼠心肌组织TNF-α蛋白表达水平。结果 Cur组小鼠心肌梗死面积及血清cTnT均低于MIRI组(P均0.01);Cur组小鼠心肌组织TLR4、TNF-αm RNA水平及NF-κB、TNF-α蛋白表达水平均低于MIRI组(P均0.05)。结论姜黄素对小鼠MIRI的心肌具有保护作用,可能是通过TLR4/NF-κB信号通路实现的。     

肢体急性动脉缺血再通术后再灌注损伤的防治

目的探讨急性肢体动脉缺血再通术后再灌注损伤的有效治疗方法。方法回顾性分析65例急性肢体动脉缺血再通术后再灌注损伤治疗患者的临床资料,上肢8例,下肢52例。结果65例急性肢体动脉缺血再通术后出现再灌注损伤38例。肢体急性动脉栓塞再通术后再灌注损伤程度较动脉硬化闭塞症继发急性血栓形成重,再通术后再灌注损伤程度与术前缺血时间及缺血程度成正比关系。动脉再通后30min出现再灌注损伤,24h达到高峰,72h后开始缓解,时间8～15d。肌筋膜切开3例,死亡2例,药物治愈33例。结论及时实施再通术是预防再灌注损伤的关键,再通术前后的有效治疗能够有效缓解再灌注损伤的发生和减轻再灌注损伤的症状。     

大鼠脑缺血再灌注后NF-κB的表达及低分子肝素的保护作用

目的探讨低分子肝素在大鼠脑局灶性缺血再灌注损伤后核转录因子NF-κB的表达及其保护作用。方法选择健康雄性SD大鼠,随机分为假手术组、缺血再灌注组、低分子肝素组,采用改良Longa[1]法制作大鼠右侧大脑中动脉闭塞局灶性脑缺血再灌注模型,观察海马CA1区NF-κB的表达情况。结果再灌注后各时间点NF-κB的表达随再灌注时间延长逐渐增加,低分子肝素组核NF-κB的表达量低于脑缺血再灌注组。结论低分子肝素能抑制模型大鼠的核转录因子NF-κB的释放,减少梗死范围,具有脑保护作用。     

肝X受体激动剂对大鼠肝移植缺血再灌注损伤的保护作用

目的观察肝X受体(liver X receptor,LXR)激动剂GW3965预处理对大鼠肝移植缺血再灌注损伤(ischemiareperfution injury,IRI)的影响及其对肝功能的保护作用。方法将雄性SD大鼠随机分为2组,GW3965预处理组于供体大鼠尾静脉注射LXR激动剂GW3965,0.3 mg/kg;对照组于相同部位注射相同剂量的生理盐水。参照改进的Kamada两袖套法建立大鼠原位肝移植模型,分别于肝移植术后3、6、24 h,采用全自动生化分析仪检测血清谷丙转氨酶(alanine aminotransferase,ALT)含量,ELISA法检测血清中肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)含量,Western blot法测定移植肝脏组织中白细胞介素-1受体相关激酶-4(interleukin-1 receptor-associated kinase-4,IRAK-4)、干扰素调节因子3(interferon-regulator 3,IRF3)蛋白的表达,凝胶迁移试验(electrophoretic mobility shift assay,EMSA)测定核因子-kappa B(nuclear factor-κB,NF-κB)的相对活性度,并观察肝脏组织的病理学变化。结果与对照组比较,GW3965预处理组血清中ALT、TNF-α含量在各时间点均明显降低(P<0.05),肝脏组织中IRAK-4、IRF3蛋白的表达以及NF-κB相对活性度也明显降低(P<0.05);GW3965预处理组各时间点肝组织的损伤均较对照组明显减轻。结论 LXR激动剂GW3965可抑制TLR4信号通路中的IRAK-4、IRF3蛋白的表达水平和NF-κB的活化,从而减轻肝移植IRI,在肝脏移植IRI中起到保护作用。     

Sox11基因对小鼠脑缺血再灌注损伤的保护作用及其机制

目的 探讨Sox11基因对小鼠脑缺血再灌注损伤(cerebral ischemia reperfusion injury,CIRI)的保护作用及其机制,为CIRI的治疗提供新的靶点。方法 建立小鼠大脑中动脉栓塞(middle cerebral artery occlusion,MCAO)模型和Neuro2A细胞氧糖剥离再灌注(oxygen glucose deprivation reperfusion,OGDR)模型,采用实时定量PCR、Western blot、免疫组织化学染色和免疫组织荧光染色技术检测Sox11在MCAO和OGDR模型中的时间和空间分布;Western blot法检测Sox11基因表达干扰后,OGDR模型中细胞凋亡和炎症反应等通路重要基因的表达改变。结果 Sox11 mRNA和蛋白表达水平在小鼠MCAO模型和Neuro2A OGDR模型中均显著上升(P=0.000 1～0.038 8);小鼠CIRI后,Sox11表达升高集中于海马体的海马齿状回(dentate gyrus,DG)区域;在OGDR模型中干扰Sox11表达后,凋亡相关蛋白Cleaved Caspase ...     

雌激素对大鼠脑缺血再灌注后的神经保护作用

目的探讨雌激素对大鼠脑缺血再灌注的保护作用。方法建立大鼠脑缺血再灌注模型,按照Zea-longa评分法测定脑缺血再灌注后神经功能评分及观察免疫组化染色标本。结果雌激素治疗组的神经功能评分及神经元损伤明显低于缺血再灌注组。结论雌激素对大鼠脑缺血再灌注损伤有一定的神经保护作用。     

热量限制对小鼠心肌缺血/再灌注损伤的影响及其作用机制

目的 探讨热量限制(caloric restriction,CR)对小鼠心肌缺血/再灌注损伤(myocardial ischemia/reperfusion injury,MI/RI)的影响及其作用机制。方法 将C57小鼠随机分为正常饮食组(AL组,自由摄食)和CR组(饮食量每2周递减10%),持续8周,监测体质量变化。每组再分为假手术组和MI/RI组,共4组,即AL+Sham组、AL+I/R组和CR+Sham组、CR+I/R组,其中MI/RI组小鼠结扎冠状动脉左前降支30 min后,再灌注24 h;Sham组只穿线不结扎。伊文思兰/TTC染色法检测小鼠心肌缺血和梗死面积;HE染色法对心肌组织进行病理学观察;相应试剂盒检测心肌组织中乳酸脱氢酶(lactate dehydrogenase,LDH)、超氧化物歧化酶(superoxide dismutase,SOD)活性及肌酸激酶同工酶(creatine kinase-MB,CK-MB)、丙二醛(malondialdehvde,MDA)含量;ELISA法检测血清中IL-1β及IL-18含量;Western blot法检测心肌组织中细胞焦亡相...     

白藜芦醇对大鼠脑缺血再灌注氧化应激损伤的影响

目的探讨白藜芦醇(Resveratrol,Res)对大鼠脑缺血再灌注氧化应激损伤的影响。方法将SD大鼠随机分为假手术组(S组)、缺血再灌注组(I/R组,线栓法复制大鼠右侧大脑中动脉栓塞模型)、Res低剂量组(15 mg/kg,I/R+R1组)和Res高剂量组(30 mg/kg,I/R+R2组),于缺血2 h再灌注24 h进行神经功能缺损评分;化学比色法测定大鼠血清和脑组织中丙二醛(Malondialdehyde,MDA)含量及超氧化物歧化酶(Superoxide dismutase,SOD)活性;TTC法测定脑梗死体积;干湿重法测定脑含水量,HE染色观察脑组织的病理改变。结果与I/R组相比,Res能改善大鼠脑缺血再灌注损伤后的神经功能缺失(P<0.01),降低血清及脑组织中MDA的含量(P<0.01),提高SOD活性(P<0.01),缩小脑梗死体积(P<0.01),降低损伤侧脑含水量(P<0.01),改善脑组织的病理变化,且呈剂量依赖性。结论 Res对大鼠局灶性脑缺血再灌注氧化应激损伤具有良好的保护作用,其机制可能与清除自由基,减轻氧化性损伤有关。     

神经节苷脂对脑缺血/再灌注损伤的保护作用

目的探讨神经节苷脂对脑缺血再灌注损伤的保护作用。方法采用Ｐｕｌｓｉｎｅｌｌｉ的四血管闭塞法 制作大鼠急性脑缺血／再灌注模型,利用高压液相色谱法观察脑缺血／再灌注期间谷氨酸和γ－氨基丁酸含量的变化, 通过图象分析仪测定神经元的面数密度及神经节苷脂对以上指标的影响。结果缺血后谷氨酸和γ－氨基丁酸含 量明显升高,再灌注后降低,神经节苷脂可降低谷氨酸含量,与盐水对照组相比差异显著（Ｐ＜０．０１）,同时增加神经 元面数密度。结论神经节苷脂通过抑制谷氨酸释放,可减轻脑缺血再灌注期间脑组织损伤。     

Ozone Biological Response in Kidneys of Rats Submitted to Warm Ischemia

A biochemical and morphofunctional renal study, applying different sessions of rectal ozone (O₃) before a warm ischemia, was performed. Rats were divided in: 1-control, a medial abdominal incision was performed for the exposure of the kidneys; 2-ischemia, animals with a bilateral renal ischemia (30?min), with subsequent reperfusion (3?h); groups 3, 4 and 5 – (O₃+ischemia), as group 2, but with previously treatment of 5, 10 and 15 sessions of rectal ozone, respectively; groups 6, 7 and 8 – (O₂+ischemia), as groups 3, 4 and 5, respectively, but using rectal oxygen. A significant decrease of the flow and renal filtration, with high values of fructosamine and phospholipase A₂, in the ischemia and oxygen groups, with respect to control and ozone groups was obtained without any statistical difference among them. Morphological alterations were significantly less in the groups pretreated with ozone, with better results for 10 and 15 sessions.     

阿魏酸钠对大鼠纤维化心肌组织中结缔组织生长因子表达的影响

目的探讨阿魏酸钠(Sodium ferulate,SF)对大鼠纤维化心肌组织中结缔组织生长因子(Connective tissue growth factor,CTGF)表达的影响。方法一次性皮下注射盐酸异丙肾上腺素(Isoproterenol,Iso)15mg/kg体重,复制Wistar大鼠心肌缺血性坏死模型,于不同时间点脱臼处死大鼠,取心脏,采用半定量RT-PCR法检测大鼠组织中CTGF基因mRNA的转录水平,免疫组化法检测CTGF蛋白的表达水平。再次复制大鼠心肌缺血坏死模型,同时注射SF进行同步干预,3周后检测大鼠心肌组织中CTGF基因mRNA的转录水平及蛋白的表达水平。结果注射Iso后24h,CTGF基因mRNA的转录水平达高峰,较正常对照组明显增加,3周时仍高于正常对照组;CTGF蛋白的表达随纤维化病变程度的加重而增加。SF干预后,CTGF基因mRNA的转录水平及蛋白的表达水平均明显下降。结论 CTGF的表达与大鼠心肌纤维化(Myocardial fibrosis,MF)程度密切相关,提示CTGF可能在MF中起重要作用;SF对CTGF的表达具有抑制作用。     

Protective Effect of Water-Soluble C60 Fullerene Nanoparticles on the Ischemia-Reperfusion Injury of the Muscle Soleus in Rats

The biomechanical parameters of muscle soleus contraction in rats and their blood biochemical indicators after the intramuscular administration of water-soluble C₆₀ fullerene at doses of 0.5, 1, and 2 mg/kg 1 h before the onset of muscle ischemia were investigated. In particular, changes in the contraction force of the ischemic muscle soleus, the integrated power of the muscle, the time to achieve the maximum force response, the dynamics of fatigue processes, and the parameters of the transition from dentate to smooth tetanus, levels of creatinine, creatine kinase, lactate and lactate dehydrogenase, and parameters of prooxidant–antioxidant balance (thiobarbituric acid reactive substances, hydrogen peroxide, and reduced glutathione and catalase) were analyzed. The positive therapeutic changes in the studied biomechanical and biochemical markers were revealed, which indicate the possibility of using water-soluble C₆₀ fullerenes as effective prophylactic nanoagents to reduce the severity of pathological conditions of the muscular system caused by ischemic damage to skeletal muscles.     

神经生长因子对大鼠视网膜缺血-再灌注损伤的保护作用

用眼内高压法造成大鼠视网膜缺血45min,然后回复常压,造成缺血-再灌注损伤。采用符合临床给药途径的眼球分注射法,小鼠颌下腺神经生长因子（NGF）250、500、1000BU／眼,于缺血损伤前及其后球旁注射,每天1次,连续4天,第10天取材病检。观察到NGF500、1000BU／眼可减轻视网膜缺血-再灌注损伤,使神经节细胞存活率增加,视网膜全层及内核层萎缩减轻。提示NGF球旁注射可扩散到视网膜,对视网膜缺血-再灌注损伤产生保护作用。     

Dose-Dependent Protective Effect of Bisperoxovanadium against Acute Cerebral Ischemia in a Rat Model of Ischemia/Reperfusion Injury

PTEN (phosphatase and tensin homologue deleted on chromosome 10) is a dual-specificity lipid and protein phosphatase. The loss of PTEN was originally discovered in numerous human cancers. PTEN inhibition by bisperoxovanadium (bpV) reduces neurological damage after ischemic brain injury. The purpose of this study was to identify the optimal neuroprotective dose of bpV when administrated after focal ischemia/reperfusion (I/R) injury in rats. Focal I/R injury was induced using the middle cerebral artery occlusion method. bpV at doses of 0.25, 0.50 and 1.0 mg/kg were injected intraperitoneally just after reperfusion, with saline serving as a vehicle control. A maximal reduction in brain injury was observed with 1.0 mg/kg bpV. This dose of bpV also significantly blocked apoptosis in the penumbral cortex of rats. This beneficial effect was associated with the increasing levels of Akt phosphorylation in the penumbral cortex. These results demonstrate that the pharmacological inhibition of PTEN protects against I/R injury in a dose-dependent manner and the protective effect might be induced through upregulation of the phosphoinositide-3 kinase/Akt pro-survival pathway, suggesting a new therapeutic strategy to combat ischemic brain injury.     

Fatty Acid Amide Hydrolase Deficiency Is Associated with Deleterious Cardiac Effects after Myocardial Ischemia and Reperfusion in Mice

Ischemic cardiomyopathy leads to inflammation and left ventricular (LV) dysfunction. Animal studies provided evidence for cardioprotective effects of the endocannabinoid system, including cardiomyocyte adaptation, inflammation, and remodeling. Cannabinoid type-2 receptor (CB2) deficiency led to increased apoptosis and infarctions with worsened LV function in ischemic cardiomyopathy. The aim of our study was to investigate a possible cardioprotective effect of endocannabinoid anandamide (AEA) after ischemia and reperfusion (I/R). Therefore, fatty acid amide hydrolase deficient (FAAH)^−/− mice were subjected to repetitive, daily, 15 min, left anterior descending artery (LAD) occlusion over 3 and 7 consecutive days. Interestingly, FAAH^−/− mice showed stigmata such as enhanced inflammation, cardiomyocyte loss, stronger remodeling, and persistent scar with deteriorated LV function compared to wild-type (WT) littermates. As endocannabinoids also activate PPAR-α (peroxisome proliferator-activated receptor), PPAR-α mediated effects of AEA were eliminated with PPAR-α antagonist GW6471 i.v. in FAAH^−/− mice. LV function was assessed using M-mode echocardiography. Immunohistochemical analysis revealed apoptosis, macrophage accumulation, collagen deposition, and remodeling. Hypertrophy was determined by cardiomyocyte area and heart weight/tibia length. Molecular analyses involved Taqman^® RT-qPCR and immune cells were analyzed with fluorescence-activated cell sorting (FACS). Most importantly, collagen deposition was reduced to WT levels when FAAH^−/− mice were treated with GW6471. Chemokine ligand-2 (CCL2) expression was significantly higher in FAAH^−/− mice compared to WT, followed by higher macrophage infiltration in infarcted areas, both being reversed by GW6471 treatment. Besides restoring antioxidative properties and contractile elements, PPAR-α antagonism also reversed hypertrophy and remodeling in FAAH^−/− mice. Finally, FAAH^−/−-mice showed more substantial downregulation of PPAR-α compared to WT, suggesting a compensatory mechanism as endocannabinoids are also ligands for PPAR-α, and its activation causes lipotoxicity leading to cardiomyocyte apoptosis. Our study gives novel insights into the role of endocannabinoids acting via PPAR-α. We hypothesize that the increase in endocannabinoids may have partially detrimental effects on cardiomyocyte survival due to PPAR-α activation.     

Effect of Long-Term Supplementation with Acetic Acid on the Skeletal Muscle of Aging Sprague Dawley Rats

Mitochondrial function in skeletal muscle, which plays an essential role in oxidative capacity and physical activity, declines with aging. Acetic acid activates AMP-activated protein kinase (AMPK), which plays a key role in the regulation of whole-body energy by phosphorylating key metabolic enzymes in both biosynthetic and oxidative pathways and stimulates gene expression associated with slow-twitch fibers and mitochondria in skeletal muscle cells. In this study, we investigate whether long-term supplementation with acetic acid improves age-related changes in the skeletal muscle of aging rats in association with the activation of AMPK. Male Sprague Dawley (SD) rats were administered acetic acid orally from 37 to 56 weeks of age. Long-term supplementation with acetic acid decreased the expression of atrophy-related genes, such as atrogin-1, muscle RING-finger protein-1 (MuRF1), and transforming growth factor beta (TGF-β), activated AMPK, and affected the proliferation of mitochondria and type I fiber-related molecules in muscles. The findings suggest that acetic acid exhibits an anti-aging function in the skeletal muscles of aging rats.