地奥司明对肾缺血/再灌注大鼠氧化应激及肾功能的影响

目的观察地奥司明(diosmin,DOSM)对大鼠肾缺血/再灌注(ischemia/resperfusion,I/R)肾组织中氧化应激水平及肾功能的影响。方法 180只SD大鼠随机分为3组:假手术组(sham operation,SO)、I/R模型组和DOSM+I/R组。采用ELISA方法测定肾组织中丙二醛(malondialdehyde,MDA)和超氧化物歧化酶(superoxide dismutase,SOD)含量的变化,同时检测血肌酐(creatinine,Cr)和尿素氮(blood urea nitrogen,BUN)水平。结果在缺血再灌注后1h、3h、6h和12h肾组织中MDA含量逐渐升高,12h达到高峰,I/R组和DOSM组均显著高于SO组(P<0.01);此后MDA逐渐下降,DOSM组血清MDA水平显著低于I/R组(P<0.01)。随再灌注时间的延长,肾组织匀浆中SOD活性显著降低,并于24h达最低水平,此后开始回升。DOSM组在6h、12h、24h和48h与I/R组相比不同程度地提高SOD的活力(P<0.01或P<0.05),与SO组相比无统计学差异。血Cr和BUN水平在DOSM+I/R组显著低于I/R组(P<0.05或P<0.01)。结论大鼠肾I/R可以引起肾组织的脂质过氧化反应增强,DOSM可通过抗氧自由基损伤及减轻脂质过氧化反应而保护肾功能。     

Calcineurin is involved in cardioprotection induced by ischemic postconditioning through attenuating endoplasmic reticulum stress

Background  Ischemic postconditioning (I-postC) is a newly discovered and more amenable cardioprotective strategy capable of protecting the myocardium from ischemia/reperfusion (I/R) injury. Endoplasmic reticulum (ER) is a principal site for secretary protein synthesis and calcium storage. Myocardial I/R causes ER stress and emerging studies suggest that the cardioprotection has been linked to the modulation of ER stress. The aim of the present study was to determine whether cardioprotection of I-postC involves reduction in ER stress through calcineurin pathway.

Methods  In the in vivo model of rat myocardial I/R, myocardial infarct size was measured by triphenyltetrazolium chloride (TTC) staining and apoptosis was detected using terminal eoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. Expression of calreticulin, C/EBP homologous protein (CHOP), caspase-12, and activation of caspase-12 in myocardium were detected by Western blotting. The activity and expression of calcineurin in myocardium were also detected.

Results  I-postC protected the I/R heart against apoptosis, myocardial infarction, and leakage of lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB). I-postC suppressed I/R-induced ER stress, as shown by a decrease in the expression of calreticulin and CHOP, and caspase-12 activation. I-postC downregulated calcineurin activation in myocardium subjected to I/R.

Conclusion  I-postC protects myocardium from I/R injury by suppressing ER stress and calcineurin pathways are not associated with the I-postC-induced suppression of ER stress-related apoptosis.

     

G蛋白偶联受体激酶4调控小鼠肾脏急性缺血再灌注损伤的机制探讨

目的 探讨G蛋白偶联受体激酶4(G protein-coupled receptor kinase 4,GRK4)对小鼠肾脏急性缺血再灌注损伤的影响及其作用机制.方法 取SPF级健康野生型[8周龄、体质量(21.34±0.42)g]和GRK4转基因型[8周龄、体质量(21.87 ±0.68)g] C57BL/6小鼠,各12只.各型分别按随机数字表法分为4组(n=6):野生型假手术对照组、野生型肾脏缺血再灌注损伤组、GRK4转基因型假手术对照组、GRK4转基因型肾脏缺血再灌注损伤组.假手术对照组均采用开腹后不阻断肾动脉血流;缺血再灌注损伤组均采用夹闭肾动脉缺血45 min再灌注24 h,建立小鼠肾脏I/R模型.各组处死小鼠后,取血标本进行肾功能检测(血肌酐、血尿素氮);HE染色观察肾脏病理形态改变,并行肾小管损伤半定量评分;测定肾脏组织中过氧化物歧化酶(superoxide dismutase,SOD)、丙二醛(malondialdehyde,MDA)等氧化应激水平改变;TUNEL染色检测肾脏组织中细胞凋亡情况;蛋白质免疫印记方法检测各组小鼠肾脏组织中GRK4和AT1受体的蛋白表达变化.结果 野生型小鼠肾脏I/R模型后肾功能受损,血肌酐、血尿素氮升高,肾脏小管上皮细胞脱落、死亡(P＜0.05);肾脏组织中GRK4蛋白表达含量增加,差异有统计学意义(P＜0.05).在GRK4过表达小鼠上研究结果发现,过表达GRK4的肾脏在缺血再灌注损伤后,肾功能损害进一步加重;肾脏病理损伤评分明显增加(P＜0.05).肾脏氧化应激水平明显上升,总SOD下降和MDA升高(P＜0.05);肾脏凋亡细胞数目显著增多(P＜0.05).肾脏组织中AT1受体表达量增加(P＜0.05),AT1受体含量的升高可以加重小管细胞氧化应激和凋亡的发生.结论 GRK4可以通过上调肾脏AT1受体表达,增加肾脏氧化应激水平和肾小管细胞凋亡,加重肾脏缺血再灌注损伤.     

白藜芦醇对大鼠肾脏缺血-再灌注损伤保护作用研究

目的：观察白藜芦醇(RES)对大鼠肾脏缺血-再灌注(I/ R)保护作用并初步探讨其相关机制。方法 SD 大鼠随机分为4组：空白对照组、I/ R 模型组、白藜芦醇(RES)处理组、RES + IR 模型组;检测各组大鼠血清肌酐(Cr)、尿素氮(BUN)及肾脏病理学改变,使用超氧化物歧化酶(SOD)活力、丙二醛(MDA)和谷胱甘肽过氧化物酶(GSH-PX)试剂盒检测肾脏组织 SOD、MDA、GSH-PX 产生;Western blot 法检测肾脏组织 p-AKT 蛋白水平。结果与空白对照组相比,I/ R模型组 Cr、BUN 含量均有升高,与 I/ R 模型组相比,RES + I/R 模型组 Cr、BUN 含量均有明显下降;病理学检测显示 RES+ I/ R 模型组肾脏损伤较 I/ R 模型组明显减轻,肾小球结构基本正常,细胞间质有少量炎性细胞浸润,基底膜稍有增厚;与空白对照组相比,I/ R 模型组 SOD、MDA、GSH-PX 含量均有升高,与 I/ R 模型组相比,RES + I/ R 模型组 SOD、GSH-PX含量均有明显下降; Western blot 检测显示,与空白对照组相比,I/ R 模型组 p-AKT 表达水平有所降低,但 RES 可提高 p-AKT 表达水平,差异有统计学意义。结论 RES 通过氧化应激保护 I/ R 肾脏损伤,其作用机制可能与 PI3K/ AKT 信号通路活化有关。     

PKC激活对离体心肌缺血再灌注自由基损伤和钙超载的影响

目的：探讨缺血预处理（IPC）保护机制中蛋白激酶C（PKC）的激活对心有缺血再灌注后的自由基损伤和钙离子（Ca^2 ）代谢的影响。方法：采用大鼠离体心脏Langendorff灌流模型，以心肌组织丙二醛（MDA）含量，线粒体中谷胱甘肽过氧化物酶（GSH－PX）活性以及线粒体Ca^2 含量，细胞肌浆网钙泵（Ca^2 －ATPase）活性作为反映心肌自由基代谢及Ca^2 代谢指标，观察IPC对上述指标的影响及PKC的可能作用。结果：与对照组比较，心肌单纯的缺血再灌注（I／R）可造成心肌明显的自由基及Ca^2 代谢的异常，经过IPC可使再灌注心肌这种代谢异常明显减轻，表现为IPC组心肌组织MDA含量、线粒体Ca^2 含量显著低于单纯I／R组（P均＜0．01），线粒体中GSH－PX活性，肌浆网Ca^2 －ATPase活性明显高于I／R组（P＜0．05），而在预处理过程中应用多粘菌素B抑制PKC的激活，则预处理的上述有益作用可被阻断。结论：PKC活化通过减轻心肌缺血再灌注后自由基损伤及Ca^2 超载而参与心肌缺血预处理保护。     

线粒体细胞色素c释放抑制剂对大鼠全脑缺血再灌注损伤炎症反应的作用

目的探讨线粒体细胞色素c抑制剂对大鼠全脑缺血再灌注后脑损伤的作用,分析线粒体乙醛脱氢酶2（ALDH2）和炎症反应在其中的机制。方法通过四血管阻断法模拟大鼠全脑缺血再灌注损伤（I/R）模型,雄性SD大鼠随机分为假手术组（Sham组）、I/R组、ALDH2激动剂Alda-1+I/R组、Bax介导的线粒体细胞色素c释放抑制剂（Bcb）+I/R组。HE染色观察海马CA1区细胞形态学的变化;免疫组织化学观察海马CA1区ALDH2及炎症小体关键蛋白NLRP3表达水平,Western blotting检测海马CA1区4-HNE、NLRP3、IL-1β、IL-18及ALDH2的蛋白水平变化。结果与Sham组比较,I/R组再灌注7 d后,I/R组海马CA1区细胞存活率明显下降;与I/R组比较,Alda-1+I/R组、Bcb+I/R组的海马CA1区神经元存活率增高（P < 0.01）。与I/R组相比,Bcb+I/R组、Alda-1+I/R组海马CA1区ALDH2蛋白表达增加,海马CA1区NLRP3、IL-1β、IL-18、4-HNE蛋白表达下降（P < 0.01）。结论大鼠全脑缺血再灌注损伤模型中,海马CA1区NLRP3表达增高;Bcb可以通过促进线粒体ALDH2的表达、降低炎症反应发挥保护作用。     

P选择素和ICAM—1在肾缺血再灌注损伤中的作用

目的 探讨Ｐ选择素和细胞间粘附分子－１（ＩＣＡＭ－１）在肾缺血再灌注损伤中的作用。方法 建立缺血再灌注损伤大鼠模型,观察缺血再灌注后肾组织Ｐ选择素和ＩＣＡＭ－１的表达,并用Ｐ选择单克隆抗体进行了治疗。结果 发现缺血再灌注后肾小管人泡变性玫片状坏死,血尿素氮（ＢＵＮ）和肌酐（ＳＣｒ）水平升高;但再灌注前５ｍｉｎ经Ｐ选择互单抗处理的动物肾组织与正常相近,肾小管上皮细胞未见变性及坏死,血ＢＵＮ和ＳＣｒ水     

家兔肠缺血—再灌注损伤时脂质过氧化的变化及其意义

目的：探讨肠缺血－再灌注（Ｉ／Ｒ）损伤时血浆及组织脂质过氧化的变化及其意义。方法：复制家兔肠Ｉ／Ｒ损伤模型，检测超氧化物歧化酶（ＳＯＤ）和黄嘌呤氧化酶（ＸＯ）活性及丙二醛（ＭＤＡ）含量。实验分为Ｉ／Ｒ损伤组及假手术（Ｓｈａｍ）对照组，并进行比较。结果：缺血前两组动物ＳＯＤ、ＸＯ及ＭＤＡ值均无统计学差异，Ｉ／Ｒ组再灌注后２ｈ与缺血前及Ｓｈａｍ组相比，ＳＯＤ活性显著下降，ＸＯ活性及ＭＤＡ含量明显增加（Ｐ〈０．０１）；此外，肺、肝等组织ＭＤＡ含量亦明显高于Ｓｈａｍ组（Ｐ〈０．０１）。结论：家兔肠Ｉ／Ｒ损伤时体内脂质过氧化过程加强，且在Ｉ／Ｒ损伤过程中起重要作用。     

Changes of sphingolipids profiles after ischemia-reperfusion injury in the rat liver

Background Hepatic ischemia-reperfusion （I/R） injury occurs in many clinical procedures. The molecular mechanisms responsible for hepatic I/R injury however remain unknown. Sphingolipids, in particular ceramide, play a role in stress and death receptor-induced hepatocellular death, contributing to the progression of several liver diseases including liver I/R injury. In order to further define the role of sphingolipids in hepatic I/R, systemic analysis of sphingolipids after reperfusion is necessary. Methods We investigated the lipidomic changes of sphingolipids in a rat model of warm hepatic I/R injury, by delayed extraction matrix-assisted laser desorption ionization time-of-flight mass spectrometry （DE MALDI-TOF-MS）. Results The total amounts of ceramide and sphingomyelin and the intensity of most kinds of sphingolipids, mainly sphingomyelin, significantly increased at 1 hour after reperfusion （P 〈0.05） and reached peaks at 6 hours after reperfusion （P 〈0.01） compared to controls. Six new forms of ceramide and sphingomyelins appeared 6 hours after reperfusion, they were （m/z） 537.8, 555.7, 567.7, 583.8, 683.5 and 731.4 respectively. A ceramide-monohexoside （m/z） 804.4 （CMH（d18：1C22：1＋Na）＋） also increased after reperfusion and correlated with extent of liver injury after reperfursion. Conclusions Three main forms of sphingolipids, ceramide, sphingomyelin and ceramide-monohexoside, are related to hepatic I/R injury and provide a new perspective in understanding the mechanisms responsible for hepatic I/R injury.     

间苯三酚对大鼠肾缺血再灌注损伤的保护作用

目的：研究间苯三酚对大鼠肾缺血再灌注损伤（ischemia reperfusion injury, IRI）的保护作用及机制。方法：将雄性Wistar大鼠48只平均分为3组（n=16）：假手术组（Sham组）切除大鼠右肾后,左肾动脉进行同等分离,但不予夹闭;对照组即肾缺血再灌注组（ischemia reperfusion, I/R组）,腹腔注射等量的生理盐水,15 min后切除大鼠右肾,无创动脉夹夹闭左肾动脉45 min;实验组即缺血再灌注间苯三酚预处理组（phloroglucinol,PG组）,腹腔注射间苯三酚注射液（30 mg/kg）,15 min后切除大鼠右肾,无创动脉夹夹闭左肾动脉45 min。每组动物再均分为两个亚组（n′=8）,分别于再灌注后6和24 h将大鼠处死。处死前经下腔静脉取血,检测血清肌酐（secrum creatinine, SCr）、尿素氮（blood urine nitrogen, BUN）;将肾于冠状位切成两半,一半组织制作成组织匀浆,取组织上清液检测丙二醛（malondialdehyde, MDA）、过氧化氢酶（catalase, CAT）、超氧化物歧化酶（superoxide dismutase, SOD）及谷胱甘肽过氧化物酶（glutathione peroxidase, GSH-Px）;另一半组织行石蜡包埋,切片进行病理组织学观察,再灌注后24 h的大鼠肾组织行核转录因子-kapa B(nuclear factor-kapa B, NF-κB)及Caspase 3免疫组织化学检测。结果：再灌注后 6 h,I/R组大鼠血清SCr和BUN分别为(103.9±10.4) μmol/L和(15.2±1.0) mmol/L,PG预处理的SCr及BUN分别为(81.8±13.4) μmol/L和(11.5±1.2) mmol/L;再灌注后24 h,I/R组大鼠血清SCr和BUN分别为(154.9±12.1) μmol/L和(28.1±1.4) mmol/L,PG预处理的SCr及BUN分别为(103.8±5.9) μmol/L和(16.0±1.0) mmol/L;PG预处理组较I/R组明显改善肾功能（P<0.05）;苏木素-伊红染色病理图片可见肾小管损伤较I/R组明显减轻（P<0.05）;经PG处理后大鼠肾组织内MDA含量较I/R组低（P<0.05）,SOD及CAT含量较I/R组高（P<0.05）,GSH-Px含量较I/R组高（P<0.05）。再灌注后24 h,经间苯三酚处理的肾组织内核因子-kapa B在细胞核内表达的水平明显降低,活化的Caspase-3亦较I/R组有所减少。结论：间苯三酚通过减轻氧化应激和炎性损伤,抑制细胞凋亡,有效改善了大鼠肾IRI。     

亚低温缺血预处理对大鼠肠缺血再灌注肾损伤的保护作用

目的探讨亚低温下缺血预处理对大鼠肠缺血再灌注肾损伤的保护作用。方法选用健康Wistar大鼠24只，随机分成3组（每组8只）：假手术对照组（sham组）、缺血再灌注组（I／R组）、亚低温预处理组（MHIP组）。夹闭大鼠肠系膜上动脉（SMA）60min造成缺血，再灌注2h后取出肾组织制成匀浆，测定超氧化物歧化酶（SOD）、谷胱甘肽过氧化酶（GSH—PX）、Ca^2＋-Mg^2＋-ATPase的活性及丙二醛（MDA）含量，观察肾组织形态细胞学变化。结果MHIP组肾组织MDA含量明显低于I／R组（P〈0．01），SOD、GSH—PX、Ca^2＋-Mg^2＋-ATPase的活性均明显高于I／R组（P〈0．01），肾细胞形态学异常变化明显减轻。结论亚低温缺血预处理能减少大鼠脂质过氧化，改善ATPase功能，减轻大鼠肠缺血再灌注所致肾损伤。     

HO-1抗大鼠肾缺血/再灌注损伤的实验研究

目的探讨诱导血红素氧合酶-1(HO-1)表达能否减轻随后的肾缺血/再灌注损伤(IRI)及其可能的机制。方法采用切除右肾,夹闭左肾动脉50min/再灌注24h的动物模型,30只雄性Wistar大鼠随机均分为3组:假手术组,缺血/再灌注(I/R)组,血晶素处理组(皮下注射血晶素30mg/(kg·d),连续2d),检测肾组织中HO-1蛋白表达及HO-1活力、丙二醛(MDA)含量、总抗氧化能力(TAOC)和血清肌酐(Cr)、尿素氮(BUN)含量及组织形态学改变。结果血晶素明显诱导了肾内HO-1表达并使其活力增加,与I/R组比较,P<0.01;与假手术组比较,I/R组Cr,BUN,MDA升高(P<0.05),TAOC降低(P<0.05),组织学损伤严重。在I/R前血晶素诱导HO-1表达可逆转上述病理改变(P<0.05)。结论肾内HO-1的诱导表达可明显改善大鼠随后的I/R性肾损伤,作用机制与其增强机体抗氧化能力有关。     

The changes of sphingolipid profiles post ischemia–reperfusion injury in the rat liver

Hepatic ischemia-reperfusion (I/R) injury occurs in many clinical procedures, including liver transplantation, hepatic trauma, and liver resection. The molecular mechanisms responsible for hepatic I/R damage however remain unknown. There is increasing evidence that sphingholipids, in particular ceramide, play a role in stress and death receptor-induced hepatocellular death, contributing to the progression of several liver diseases including liver I/R injury. In order to further define the role of sphingolipids in hepatic I/R, systemic analysis of sphingolipids after reperfusion is necessary. In the present study, we investigated the lipidomic changes of sphingolipids in a rat model of warm hepatic I/R injury, by delayed extraction matrix-assisted laser desorption ionization time-of-flight mass spectrometry (DE MALDI-TOF-MS). The total amounts of ceramide and sphingomyelin and the intensity of most kinds of spingolipids, mainly sphingomyelin, significantly increased 1 hr post-reperfusion (p<0.05) and reached peaks at 6 hrs post-reperfusion (p<0.01) compared to controls. Six new forms of ceramide and sphingomyelins appeared 6 hrs post-reperfusion, (m/z) 537.8, 555.7, 567.7, 583.8, 683.5, 731.4. Interestingly, a ceramide- monohexoside (m/z) 804.4 (CMH[d18:1C22:1+Na]+) also increased post-reperfusion and correlated with extent of liver injury after reperfursion. Three main forms of sphingolipids, ceramide, sphingomyelin and ceramide- monohexoside, are related to hepatic I/R injury and provide a new perspective in understanding the mechanism(s) responsible for hepatic I/R injury.     

Protective role of mitochondrial K-ATP channel and mitochondrial membrane transport pore in rat kidney ischemic postconditioning

Background  Previous studies suggested that mechanical intervention during early reperfusion, or ischemia postconditioning (IPo), could protect kidneys against renal ischemia reperfusion injury (RIRI). However, the mechanisms responsible for this protection remain unclear. This study therefore investigated the protection afforded by IPo in rat kidneys in vivo, and the roles of mitochondrial K_ATP channels (mitoK_ATP) and mitochondrial permeability transition pores (MPTPs), by inhibiting mitoK_ATP with 5-hydroxydecanoate (5-HD), and by directly detecting open MPTPs using calcein-AM and CoCl₂.

Methods  Thirty-five male Sprague-Dawley rats were randomly assigned to sham-operation (S), ischemia-reperfusion (I/R), IPo, ischemia reperfusion with 5-HD (I/R+5-HD), or IPo with 5-HD (IPo +5-HD) groups. Rats in each group were sacrificed after 6 hours of reperfusion by heart exsanguination or cervical dislocation under anesthesia. RIRI was assessed by determination of creatinine and blood urea nitrogen (BUN), and by examination of histologic sections. The roles of mitoK_ATP and MPTP were investigated by analyzing fluorescence intensities of mitochondria, mitochondrial membrane potential, intracellular reactive oxygen species (ROS) and intracellular calcium, using appropriate fluorescent markers. The relationship between apoptosis and RIRI was assessed by determining the apoptotic index (AI) of kidney tubular epithelial cells.

Results  The RIRI model was shown to be successful. Significantly higher levels of creatinine and BUN, and abnormal pathology of histologic sections, were observed in group I/R, compared with group S. 5-HD eliminated the renoprotective effects of IPo. Mitochondrial and mitochondrial membrane potential fluorescence intensities increased, and intracellular calcium, ROS fluorescence intensities and AI decreased in group IPo, compared with group I/R. However, mitochondrial and mitochondrial membrane potential fluorescence intensities decreased, and intracellular calcium and ROS fluorescence intensities and AI increased in group IPo+5-HD, compared with group IPo.

Conclusions  mitoK_ATP and MPTPs participated in IPo-induced renoprotective mechanisms in rat kidneys subjected to RIRI, possibly through decreased renal tubular epithelial cell apoptosis. 

     

益生注射液对肾脏热缺血再灌注氧化应激损伤的作用研究

目的　观察益生注射液 (YM)能否减轻小鼠肾脏热缺血再灌注 (I/ R)损伤。方法　 C5 7BL/ 6小鼠肾脏热缺血 5 0 m in,再灌注 2 4 h取血和组织。术前 12 h和 30 m in分别腹腔给予不同剂量的 YM。观察 YM对 I/ R引起的氧化应激、炎症介质的影响。结果　 I/ R导致小鼠肾脏严重损伤。给予 YM(5、15、2 5 m g/ kg) ,肾脏丙二醛(MDA)水平分别降低 16 .6 %、2 5 .0 %和 35 .5 % ,超氧化物歧化酶 (SOD)活性分别增加约 38.7%、4 8.3%和76 .1%。YM(2 5 m g/ kg)可明显抑制 ICAM- 1的表达上调。结论　 YM至少部分通过降低活性氧的产生、减少粘附分子的表达来减轻小鼠肾脏 I/ R损伤     

线粒体融合与裂变在右美托咪定减轻小鼠脑缺血再灌注损伤中的作用及其机制

目的 探讨右美托咪定（DEX）对小鼠脑缺血/再灌注（I/R）损伤的影响及线粒体融合与裂变在其中的作用。方法 将雄性ICR小鼠随机分为假手术（sham）组、缺血/再灌注（I/R）组、缺血/再灌注+右美托咪定（I/R+DEX）组、缺血/再灌注+右美托咪定+dorsomorphin（I/R+DEX+dorsomorphin）组。采用改良线栓法制备小鼠大脑中动脉栓塞模型,于缺血前30 min 腹腔注射DEX50 μg/kg,缺血1 h,再灌注24 h;采用Longa五分法对小鼠进行神经行为学评分;TTC染色法检测小鼠脑梗死体积,并计算脑梗死体积百分率;透射电镜法观察线粒体形态变化;免疫印迹法检测磷酸化AMP蛋白激酶、线粒体融合蛋白2、线粒体裂变相关蛋白的表达变化。结果 DEX 预处理降低了 I/R 组小鼠神经行为学评分和脑梗死体积百分率,在使用 DEX 的基础上加用dorsomorphin后,小鼠神经行为学评分和脑梗死体积百分率升高（P<0.01）;电镜结果显示,DEX减轻了缺血再灌注导致的线粒体损伤（P<0.01）,线粒体形态有所恢复。免疫印迹检测结果显示,DEX预处理增加了磷酸化AMP蛋白激酶、线粒体融合蛋白2表达,降低了线粒体裂变相关蛋白表达,而加用dorsomorphin后,磷酸化AMP蛋白激酶、线粒体融合蛋白2表达明显降低,线粒体裂变相关蛋白表达显著增加（P<0.01）。结论 DEX预处理可以减轻I/R损伤,其机制可能与激活AMPK从而促进线粒体融合 及抑制线粒体裂变有关。     

肿瘤坏死因子-α、白细胞介素-1β在大鼠肾缺血后处理的变化及意义

摘　　　要 目的　 成功建立肾脏缺血后再灌注损伤大鼠模型,探讨缺血后处理在大鼠肾缺血再灌注损伤中促炎因子肿瘤坏死因子TNF-α、白细胞介素IL-1β表达变化及意义。 方法 夹闭大鼠左肾动静脉复制大鼠肾缺血再灌注损伤模型。雄性Wistar大鼠30只随机分成3组：缺血再灌注（IR,n=10）,缺血后处理组（IPo,n=10）,假手术组（S,n=10）。免疫组化检测肾组织TNF-α表达和酶联免疫的方法(ELISA法)检测血清促炎因子TNF-α、IL-1β的含量。 结果　 与S组相比,I/R组TNF-α蛋白表达阳性细胞数明显增多,差异具有统计学意义(p<0.05),与S组相比, IPo组TNF-α蛋白表达阳性细胞数增多,但明显少于I/R组,差异具有统计学意义(p<0.05);S组血清肿瘤坏死因子TNF-α、白细胞介素IL-1β水平分别为12.24士3.21pg/mL和 15.34士4.15pg/Ml,I/R组分别达到69.19士13.17pg/mL和89.46士15.75pg/mL,与S组相比统计学上有差异(p<0.05)。IPo组TNF-α、IL-1β水平分别为43.18士11.87pg/mL、58.92士12.14pg/mL,与I/R组对照组比较统计学上有显著差异(p<0.05)。 结论 1. 肿瘤坏死因子TNF-α、白细胞介素IL-1β参与了肾的缺血再灌注损伤过程。 2． 缺血后处理对肾起保护作用,能减轻促炎症细胞因子的浸润和释放。 关键词　缺血后处理;再灌注损伤;肾缺血;促炎症细胞因子     

The effect of quercetin, a bioflavonoid on ischemia/reperfusion induced renal injury in rats

There is increasing evidence to suggest that toxic oxygen radicals play a role in the pathogenesis of ischemia/reperfusion (I/R) injury in the kidney. This study was designed to investigate the effects of quercetin (Qr), a bioflavonoid in ischemia-reperfusion induced renal failure in rats. The effect of quercetin against the damage inflicted by reactive oxygen species (ROS) during renal I/R was investigated in Sprague-Dawley rats using histopathological and biochemical parameters. In one set of experiments, animals were unilaterally nephrectomized and subjected to 45 min of left renal pedicle occlusion, and in another set both renal pedicles were occluded for 45 min followed by 24 h of reperfusion. Quercetin (2 mg/kg, 30 mg/kg, i.p. and 100 mg/kg, p.o.) was administered 2 h prior to ischemia. At the end of the reperfusion period, rats were sacrificed. Thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) levels, glutathione reductase (GR), catalase (CAT), and superoxide dismutase (SOD) activities were determined in renal tissue. Serum creatinine and blood urea nitrogen (BUN) concentrations were measured for the evaluation of renal function. Ischemic control animals demonstrated severe deterioration of renal function, renal morphology and a significant renal oxidative stress. Pretreatment of animals with quercetin (2 mg/kg and 30 mg/kg, i.p.) markedly attenuated renal dysfunction, morphological alterations, reduced elevated TBARS levels and restored the depleted renal antioxidant enzymes, whereas the (100 mg/kg, p.o.) dose of quercetin failed to revert the renal I/R induced changes. The findings imply that ROS play a causal role in I/R induced renal injury and quercetin exerts protective and deleterious effects in the kidney, depending upon the dose.     

内质网与细胞凋亡

内质网 (endoplasmicreticulum ,ER)广泛存在于真核细胞中 ,是调节蛋白质合成及合成后折叠、聚集的场所 ,是调节细胞的应激反应及细胞钙水平的场所 ,也是胆固醇、类固醇及许多脂质合成的场所。ER应激在细胞凋亡中起重要作用 ,现就ER应激在细胞中的作用、ER应激与Ca2 + 水平的调节及与相关凋亡蛋白之间的关系等方面进行综述。     

Similarities between ozone oxidative preconditioning and ischemic preconditioning in renal ischemia/reperfusion injury

BACKGROUND: Many studies indicate that the production of reactive oxygen species (ROS) after renal ischemia/reperfusion (I/R) may initiate the cascade of cellular injury. It has been demonstrated that ozone oxidative preconditioning (OzoneOP) may prevent the damage induced by ROS and attenuate renal I/R injury. On the basis of those results, we postulated that OzoneOP was similar to the ischemic preconditioning (IP). The aim of our present work was to assess whether the combination of OzoneOP and IP provided synergistic protection. METHODS: Seven groups of rats were classified as follows: 1) sham-operated control; 2) I/R; 3) OzoneOP+I/R; 4) IP+I/R; 5) OzoneOP+IP+I/R; 6) O2+I/R; 7) sham-operated control+OzoneOP. Rats were sacrificed at 24 h after I/R injury. Serum and tissue were taken to determine urea nitrogen (BUN), creatinine (Cr), nitric oxide (NO), histological examination, and NO synthase (endothelial, eNOS and inducible, iNOS) expression. Malondialdehyde (MDA) content, glutathione (GSH) content, superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity were determined in renal tissue. RESULTS: Renal dysfunction, histological damage, and renal oxidative stress were significantly improved by OzoneOP or IP alone. OzoneOP+IP could not further relieve severe renal damage. Either IP or OzoneOP treatment alone increased NO release and NO synthase (endothelial, eNOS and inducible, iNOS) expression. The combination of OzoneOP and IP could not further enhance NO levels and NOS expression. CONCLUSIONS: These findings indicate that both of the preconditioning settings shared similar mechanisms of protection in the parameters measured. However, OzoneOP combined with IP had no synergistic effect. IP and OzoneOP appeared to share a common mediator: NO. These findings suggested the potential role of OzoneOP against renal failure during surgery or transplantation.