Impact of renal ischemia/reperfusion injury on the rat Kupffer cell as a remote cell: A biochemical,histological, immunohistochemical,and electron microscopic study

Almost all transplanted solid organs are exposed to some degree of ischemia-reperfusion (IR) damage. It is interesting to know that this IR damage affects various remote tissues including the liver and resulted in serious adverse effects. Liver injury triggers different responses of liver tissue especially Kupffer cells (KCs). The goal of this current study is to assess the biochemical and morphological changes of hepatic KCs after the induction of renal ischemia-reperfusion (RIR) and point out their role in remote liver injury after RIR.Sixteen male Sprague-Dawley rats were randomly divided into two equal groups: Group I; sham group. Group II; renal ischemia reperfusion (IR) group in which rats were exposed to renal ischemia for 45 min followed by renal reperfusion for 48 h. Three rats from each group were subjected to charcoal injection to evaluate KCs activity. Specimens of rat liver from each group were obtained and processed for biochemical, light microscopic and ultramicroscopic examination. The current results showed elevated serum levels of AST and ALT. The liver HGF-α protein expression increased in IR group compared to the sham group. In IR group, numerous charcoal labeled KCs were observed mainly localized around the central vein. Scanning electron micrographs showed complex primary and secondary foot process of the KCs. Ultrastructural study showed KCs with multiple cytoplasmic vacuoles, lysosomes and mitochondria, rough endoplasmic reticulum and ribosomes. Immuno-histochemical study showed more tumor necrosis factor-α (TNF-α) expression in KCs than the sham group. These results collectively demonstrated that renal IR produced biochemical and morphological changes in the liver KCs and theses cells might have a role in the remote liver injury after renal IR. This might be one of the mechanisms through which RIR affects the liver.     

Cathepsin g is required for sustained inflammation and tissue injury after reperfusion of ischemic kidneys

Neutrophil activation to release granules containing proteases and other enzymes is a primary cause of tissue damage during ischemia/reperfusion injury. Because the contribution of specific granule enzymes to this injury remains poorly defined, the role of cathepsin G in renal ischemia/reperfusion injury was tested. Bilateral renal ischemia led to the expiration of 64% of wild-type mice within 4 days of reperfusion, whereas all cathepsin G-deficient mice survived. Serum creatinine increased to similar levels at 24 hours after reperfusion and then decreased to background in both groups of mice. Ischemic kidneys from both groups had similar levels of neutrophil infiltration and of CXCL1, CXCL2, and myeloperoxidase protein 9 hours after reperfusion, but at 24 hours, these acute inflammatory response components were decreased more than 50% in kidneys from cathepsin G-deficient versus wild-type mice. Ischemic kidneys from surviving wild-type mice had severe tubular necrosis and tubular cell apoptosis 24 hours after reperfusion with subsequent development of fibrosis 30 days later. In contrast, ischemic kidneys from cathepsin G-deficient mice had a 70% decrease in tubular cell apoptosis with little detectable collagen deposition. These data identify cathepsin G as a critical component sustaining neutrophil-mediated acute tissue pathology and subsequent fibrosis after renal ischemia/reperfusion injury.     

兔肾缺血再灌注损伤时TNF-α、IL-6和bFGF的变化及当归的影响

目的:探讨当归对兔肾缺血再灌注损伤的防治作用及其机制。方法:健康成年日本大耳白兔25只, 随机均分为假手术对照(control)组、单纯缺血再灌注(IR)组和缺血再灌注+当归(RAS+IR)组。在肾缺血1h再灌注48h后取肾组织作电镜检查, 并测血清肌酐(Cr)、肾组织肿瘤坏死因子(TNF-α)、白细胞介素-6(IL-6)和碱性成纤维细胞生长因子(bFGF)含量。结果:IR组肾组织变性改变显著, RAS+IR组病变轻微;IR组Cr、TNF-α和IL-6含量显著高于control组(P<0.05, P<0.05和P<0.01);RAS+IR组上述指标显著低于IR组。IR组bFGF含量显著低于control组(P<0.01), RAS+IR组bFGF含量显著高于IR组(P<0.01)和control组(P<0.05).结论:当归具有防治肾IR损伤的作用, 其机制可能与其对TNF-α、IL-6和bFGF等细胞因子的调控有关。     

彩色多普勒超声评价肾缺血再灌注后模型兔肾动脉血流动力学变化及与肾功能的关系

背景：既往对肾缺血再灌注损伤诊断主要依靠实验室生化检查及病理检查,彩色多普勒超声仪能无创快速动态显示肾缺血再灌注后肾血流的变化。 目的：运用彩色多普勒超声评价兔肾缺血再灌注后肾动脉血流动力学变化,并探讨其与肾功能指标血尿素氮和血肌酐变化之间的相关性。 方法：随机数字表法将大白兔分为对照组、假手术组、缺血再灌注组。缺血再灌注组肾缺血再灌注模型;假手术组仅行右肾切除;对照组不作手术处理。前两组按照不同时间点再分为3个亚组进行观察。 结果与结论：随着兔肾缺血再灌注损伤加重,各级肾动脉收缩期峰值流速、搏动指数、阻力指数及血清尿素氮和血肌酐逐渐增大,24 h达高峰,叶间动脉最先出现改变血流动力学改变,其中阻力指数是反映肾缺血再灌注损伤程度最敏感指标。提示彩色多普勒超声是一种评价肾缺血再灌注损伤程度的有效方法。     

Hepatic ischemic preconditioning provides protection against distant renal ischemia and reperfusion injury in mice

We previously demonstrated that there are acute and delayed phases of renal protection against renal ischemia and reperfusion (IR) injury with renal ischemic preconditioning (IPC). This study assessed whether hepatic IPC could also reduce distant renal IR injury through the blood stream-mediated supply of reactive oxygen species (ROS). Male C57BL/6 mice were randomly divided into four groups: group I, sham operated including right nephrectomy; group II (IR), left renal ischemia for 30 min and reperfusion injury; group III (IPC-IR), hepatic ischemia for 10 min followed by 10 min of reperfusion before left renal IR injury; group IV (MPG - IPC + IR), pretreated with 100 mg/kg N-(2-mercaptopropionyl)-glycine (MPG) 15 min before hepatic IPC and left renal IR injury. Renal function, histopathologic findings, proinflammatory cytokines, and cytoprotective proteins were evaluated 15 min or 24 hr after reperfusion. Hepatic IPC attenuated the expression of proinflammatory cytokines, tumor necrosis factor α, intercellular adhesion molecule 1, and induced inducible nitric-oxide synthase, and the phosphorylation of Akt in the murine kidney. Renal function was better preserved in mice with hepatic IPC (group III) than groups II or IV. Hepatic IPC protects against distant renal IR injury through the blood stream-delivery of hepatic IPC-induced ROS, by inducing cytoprotective proteins, and by inhibiting inflammatory reactions.     

Noninvasive evaluation of renal pH homeostasis after ischemia reperfusion injury by CEST‐MRI

Acute kidney injury (AKI) in mice caused by sustained ischemia followed by reperfusion is associated with acute tubular necrosis and renal dysfunctional blood flow. Although the principal role of the kidney is the maintenance of acid–base balance, current imaging approaches are unable to assess this important parameter, and clinical biomarkers are not robust enough in evaluating the severity of kidney damage. Therefore, novel noninvasive imaging approaches are needed to assess the acid–base homeostasis in vivo. This study investigates the usefulness of MRI‐chemical exchange saturation transfer (CEST) pH imaging (through iopamidol injection) in characterizing moderate and severe AKI in mice following unilateral ischemia reperfusion injury. Moderate (20 min) and severe (40 min) ischemia were induced in Balb/C mice, which were imaged at several time points thereafter (Days 0, 1, 2, 7). A significant increase of renal pH values was observed as early as one day after the ischemia reperfusion damage for both moderate and severe ischemia. MRI‐CEST pH imaging distinguished the evolution of moderate from severe AKI. A recovery of normal renal pH values was observed for moderate AKI, whereas a persisting renal pH increase was observed for severe AKI on Day 7. Renal filtration fraction was significantly lower for clamped kidneys (0.54–0.57) in comparison to contralateral kidneys (0.84–0.86) following impairment of glomerular filtration. The severe AKI group showed a reduced filtration fraction even after 7 days (0.38 for the clamped kidneys). Notably, renal pH values were significantly correlated with the histopathological score. In conclusion, MRI‐CEST pH mapping is a valid tool for the noninvasive evaluation of both acid–base balance and renal filtration in patients with ischemia reperfusion injury.     

大鼠缺血再灌流后肾小管细胞凋亡与增殖的研究

目的：研究缺血性肾小管损伤与修复过程中细胞的增殖与凋亡。方法：暂时夹闭在鼠左肾动静脉４５分钟制肾缺血再灌流动物模型。应用ＨＥ染色、ＴＵＮＥＬ法、ＰＣＮＡ免疫组化及透射电镜观察。结果：肾缺血再灌流６小时至１周出现肾小管上皮细胞凋亡。缺血４５分钟增殖指数（ＰＩ）显著降低。缺血再灌流１２至７２小时ＰＩ显著升高。细胞凋亡的高峰出现在缺血再灌流１２小时。而ＰＩ的峰值在２４小时。结论：缺血引起的细胞增殖水平下     

Generation of endogenous hydrogen sulfide by cystathionine gamma-lyase limits renal ischemia/reperfusion injury and dysfunction

The generation of endogenous hydrogen sulfide may either limit or contribute to the degree of tissue injury caused by ischemia/reperfusion. A total of 74 male Wistar rats were used to investigate the effects of endogenous and exogenous hydrogen sulfide in renal ischemia/reperfusion. Administration of the irreversible cystathionine gamma-lyase (CSE) inhibitor, dL-propargylglycine, prevented the recovery of renal function after 45 min ischemia and 72 h reperfusion. The hydrogen sulfide donor sodium hydrosulfide attenuated the (renal, tubular, and glomerular) dysfunction and injury caused by 45 min ischemia and 6 h reperfusion. Western blot analysis of kidneys taken at 30 min reperfusion showed that sodium hydrosulfide significantly attenuated phosphorylation of mitogen-activated protein kinases (p-38, c-JUN N-terminal protein kinase 1/2, and extracellular signal-regulated kinase 1/2) and activation of nuclear factor-kappaB. At 6 h reperfusion, sodium hydrosulfide significantly attenuated the histological score for acute tubular necrosis, the activation of caspase-3 and Bid, the decline in the expression of anti-apoptotic Bcl-2, and the expression of nuclear factor-kappaB-dependent proteins (inducible nitric oxide synthase, cyclo-oxygenase-2, and intercellular adhesion molecule-1). These findings suggest that (1) the synthesis of endogenous hydrogen sulfide by CSE is essential to protect the kidney against ischemia/reperfusion injury and dysfunction and aids in the recovery of renal function following ischemia/reperfusion, (2) hydrogen sulfide generated by sodium hydrosulfide reduces ischemia/reperfusion injury and dysfunction, and morphological changes of the kidney, and (3) the observed protective effects of hydrogen sulfide are due to both anti-apoptotic and anti-inflammatory effects.     

黄芪和当归注射液对兔肾缺血再灌注损伤时ATP酶的影响

目的：观察黄芪、当归注射液在肾缺血再灌注（IR）损伤中的作用及机制。方法：将33只健康成年日本大耳白兔，随机分为手术对照（control)组、单纯肾缺血再灌（IR）组、黄芪注射液处理IR组（黄芪＋IR）和当归注射液处理IR（当归＋IR）组。肾缺血1h再灌注48h,取肾作电镜检查；测血清肌酐（Cr)、肾组织中ATP酶活性。结果：IR组肾组织变性改变显，黄芪、当归组病变较IR组明显减轻。与对照组相比，IR组血清Cr的含量升高（P＜0．05），肾中ATP酶活性降低（P＜0．05）；黄芪＋IR组，当归＋IR组较IR组血清Cr含量降低（P＜0．05），肾中ATP酶活性升高（P＜0．05），同对照组差异无显性（P＞0．05）。黄芪＋IR组与当归＋IR组血清Cr含量及肾中ATP酶活性差异无显性（P＞0．05）。结论：黄芪和当归可能通过保护ATP酶而减轻IR肾损伤。     

Extracellular signal-regulated kinase activation during renal ischemia/reperfusion mediates focal adhesion dissolution and renal injury

Acute renal failure due to ischemia/reperfusion involves disruption of integrin-mediated cellular adhesion and activation of the extracellular signal-regulated kinase (ERK) pathway. The dynamics of focal adhesion organization and phosphorylation during ischemia/reperfusion in relation to ERK activation are unknown. In control kidneys, protein tyrosine-rich focal adhesions, containing focal adhesion kinase, paxillin, and talin, were present at the basolateral membrane of tubular cells and colocalized with short F-actin stress fibers. Unilateral renal ischemia/reperfusion caused a reversible protein dephosphorylation and loss of focal adhesions. The focal adhesion protein phosphorylation rebounded in a biphasic manner, in association with increased focal adhesion kinase, Src, and paxillin tyrosine phosphorylation. Preceding phosphorylation of these focal adhesion proteins, reperfusion caused increased phosphorylation of ERK. The specific mitogen-activated protein kinase kinase 1/2 inhibitor U0126 prevented ERK activation and attenuated focal adhesion kinase, paxillin, and Src phosphorylation, focal adhesion restructuring, and ischemia/reperfusion-induced renal injury. We propose a model whereby ERK activation enhanced protein tyrosine phosphorylation during ischemia/reperfusion, thereby driving the dynamic dissolution and restructuring of focal adhesions and F-actin cytoskeleton during reperfusion and renal injury.     

晚期缺血预适应促进低氧诱导因子的表达减轻肾脏缺血再灌注损伤

目的: 探讨晚期缺血预适应对肾脏缺血再灌注损伤的作用,以及低氧诱导因子1α(HIF-1α)在其中的作用。方法: 将雄性C57/BL6N小鼠随机分为3组:假手术组(sham)、缺血再灌注组(IR)和缺血预适应组(IPC)。采用夹闭双侧肾蒂30 min后恢复灌注的方法建立肾缺血再灌注小鼠模型;缺血预适应组4 d前给予肾脏15 min预缺血。观察缺血预处理对再灌注后不同时点血肌酐(Scr)、尿素氮(BUN)、肾组织形态学和细胞凋亡的影响。采用免疫组化及Western印迹法,分析HIF-1α在肾组织的表达;采用实时定量RT-PCR法,检测血管内皮生长因子(VEGF)和葡萄糖转运子-1(Glut-1)的mRNA表达。结果: 再灌注24 h后,IPC组小管间质损伤程度较IR组显著减轻,Scr、BUN水平以及小管上皮细胞凋亡明显下降。IPC组的HIF-1α核内表达显著高于IR组,且HIF-1下游靶基因VEGF和Glut-1的mRNA表达亦显著增加。结论: 晚期缺血预适应能够显著改善缺血再灌注后肾脏的形态和功能,这种保护作用可能与促进低氧诱导因子高表达有关。     

苦参素降低大鼠肾脏缺血-再灌注损伤

目的观察苦参素的抗大鼠肾缺血再灌注损伤的作用并从抗氧化方面探讨其机制。方法用双肾肾蒂夹闭45 min建立IRI模型,将SD大鼠随机分为假手术组(sham);缺血再灌注组(I/R);苦参素治疗组(oxymatrine+I/R)。苦参素治疗组又分为高、中和低3个剂量组,在缺血再灌注前,连续7 d经腹腔注射。用自动生化仪测定血清肌酐(Scr)和尿素氮(BUN)水平,观察苦参素对肾缺血再灌注的保护作用及确定最优剂量;以最优剂量干预用分光分析法测定肾组织丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)水平。结果不同剂量组均能明显减轻肾脏IRI的病理形态学改变,改善肾功能。与I/R组相比,再灌注72 h后,MDA水平,血清肌酐(Scr)和尿素氮(BUN)水平明显降低(P<0.05);苦参素治疗组的CAT、T-SOD、GSH-Px活性改善明显(P<0.05)。苦参素无体外抗氧化作用。结论苦参素对大鼠肾缺血再灌注损伤具有保护作用,作用机制可能与调控机体的抗氧化系统有关。     

Sevoflurane pretreatment enhance HIF-2α expression in mice after renal ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury often occurs, which is one of the major causes of acute kidney injury, thus increasing in-hospital mortality. HIF-2α has a protective role against ischemia of the kidney. Renal ischemia/reperfusion under sevoflurane anesthesia resulted in drastic improvements in renal function. We hypothesized that underlying mechanism responsible for renal protection from sevoflurane pretreatment involves the upregulation of HIF-2α. Sevoflurane pretreatment were performed on WT and HIF-2α knockout mice before renal ischemia/reperfusion. Levels of blood urea nitrogen (BUN) and serum creatinine (Cr) were determined with a standard clinical automatic analyzer. The left kidneys were taken for morphological examination. Expression of HIF-2α in kidney tissue was examined by western blotting. In WT mice, group I/R injury had significantly higher BUN and Cr levels than group control, whereas group I/R + Sev had significantly lower BUN and Cr levels than group I/R injury. Renal HIF-2α expression levels were significantly higher in WT mice of group I/R + Sev than group control and group I/R. In HIF-2α^-/- mice, group I/R + Sev showed much higher BUN and Cr levels and severer histological damage than group I/R and group control. Renal HIF-2α expression levels were significantly higher in WT mice of group I/R + Sev than group control and group I/R. Our findings suggested that HIF-2α might contribute to the beneficial effect of sevoflurane in renal ischemia/reperfusion injury.     

缺血后处理对缺血再灌注家兔肾皮质血流量的影响

目的:观察缺血后处理(IPo)对缺血再灌注(I/R)家兔肾皮质血流量的影响,探讨IPo的肾保护作用。方法:24只日本大耳白兔随机分成3组:假手术组(S组),I/R组,IPo组,每组8只,均用3%戊巴比妥钠麻醉。I/R组采用结扎并切除右肾,分离并夹闭左肾动脉45min,再灌注60min制备肾I/R模型;S组麻醉后开腹,切除右肾,分离左肾及动脉;IPo组在切除右肾、夹闭左肾动脉45min后,再灌1min,缺血1min,反复4次,再全面恢复血流灌注60min;各组取股动脉血液用去蛋白终点法测定血浆肌酐(Cr)含量,二乙酰-肟显色法测定血尿素氮(BUN)含量;应用激光多普勒血流监测仪观测肾皮质血流量。结果:与S组比较,I/R组血浆Cr和BUN浓度升高(P<0.05),肾皮质血流量显著降低(P<0.05)。与I/R组相比,IPo组血浆Cr和BUN浓度降低(P<0.05),肾皮质血流量升高(P<0.05)。结论:IPo可以增加I/R后肾脏皮质的血液灌流量,改善肾功能。     

Effects of ischemic preconditioning on the systemic and renal hemodynamic changes in renal ischemia reperfusion injury

Background: Ischemic preconditioning (IPC) could protect against subsequent renal ischemia reperfusion injury (IRI). However, the mechanisms underlying IPC remain far from complete. Hence, we explored the effects of IPC on the renal and systemic hemodynamic changes, renal function and morphology, as well the involvement of endothelial and inducible nitric oxide synthase (eNOS/iNOS), and nitric oxide (NO). Methods: Male Sprague-Dawley rats were randomly divided into five groups after right-side nephrectomy: Sham group (surgery without vascular clamping); IRI group (the left renal artery was clamped for 45 min); IPC group (pretreated with 15 min of ischemia and 10 min of reperfusion); IPC + vehicle group (administrated with 0.9% saline 5 min before IPC); and IPC + N^G-nitro-L-arginine methylester (L-NAME) group (pretreated with L-NAME 5 min prior to IPC). The renal and systemic hemodynamic parameters, renal function and morphology, as well as eNOS, iNOS, and NO expression levels in the kidneys were measured at the indicated time points after reperfusion. Results: IPC rats exhibited significant improvements in renal function, morphology, and renal artery blood flow (RABF), without obvious influence on the systemic hemodynamics and renal vein blood flow. Increased eNOS, iNOS, and NO expression levels were detected in the kidneys of IPC rats 24 h after reperfusion. Furthermore, the beneficial effects were fully abolished by the administration of L-NAME. Conclusions: The results suggest that IPC contributes to early restoration of RABF, probably through eNOS/iNOS-mediated NO production, thereby alleviating the renal dysfunction and histological damage caused by IRI.     

右美托咪定抑制肾缺血/再灌注炎性反应

背景：在缺血/再灌注肾脏损伤的防治研究中,用药物激活或抑制机体某些因子从而保护肾组织,对肾移植和移植物的功能恢复有着重要意义。 目的：探索右美托咪定对大鼠肾缺血/再灌注炎性因子及C-X-C型趋化因子受体4表达的影响。 方法：40只大鼠随机等分为假手术组、缺血再灌注组、右美托咪定预处理组及右美托咪定后处理组。后3组行右肾切除,左肾缺血45 min,再灌注60 min,造肾缺血再灌注模型;右美托咪定预处理组于大鼠股静脉穿刺置管后泵注1 μg/kg右美托咪定,10 min后改为0.5 μg/kg,泵注30 min直至缺血即刻;右美托咪定后处理组于左肾再灌注后静脉泵注0.5 μg/kg右美托咪定 30 min。 结果与结论：肾脏缺血再灌注大鼠肾脏损伤严重,炎症明显,肾小管扩张,有肾小球肾炎表现,血清中白细胞介素1β和肿瘤坏死因子α水平显著升高(P < 0.05),血清和肾脏中C-X-C型趋化因子受体4水平也明显增加(P < 0.05);经右美托咪定预处理或后处理的肾缺血再灌注大鼠血清中白细胞介素1和肿瘤坏死因子α水平明显降低(P < 0.05),血清和肾脏中C-X-C型趋化因子受体4水平也明显降低(P < 0.05)。提示肾缺血再灌注可致以炎性反应为特征的肾损伤;右美托咪定可以抑制炎性反应并弱化C-X-C型趋化因子受体4的表达,具有一定的肾保护作用。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：     

异丙酚通过抑制JAK/STAT通路减轻肝冷缺血再灌注大鼠肾损伤

目的:探讨JAK/STAT信号通路在异丙酚减轻大鼠肝冷缺血再灌注后肾损伤中的作用。方法:SD大鼠随机分为4组(n=8):假手术组(sham组);肝冷缺血再灌注模型组(I/R组);异丙酚组(Pro组),于再灌注前5 min经右侧股静脉给予异丙酚20 mg·kg~(-1)·h~(-1)持续泵注30 min;JAK2抑制剂AG490组(AG490组),于建立模型前30 min腹腔注射AG490 10 mg/kg。再灌注6 h后处死大鼠,采集血样和肾组织标本,检测血清肌酐(Cr)、尿素氮(BUN)、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)的浓度及肾组织超氧化物歧化酶(SOD)和丙二醛(MDA)的水平;观察肾组织的病理学改变,并进行肾小管损伤评分;检测肾组织细胞凋亡并计算凋亡指数(AI);检测p-JAK2、p-STAT_1和p-STAT_3的蛋白水平。结果:与sham组比较,I/R组血清的Cr和BUN浓度、肾组织的MDA含量、肾小管损伤评分及AI均明显升高,SOD活性降低,p-JAK2、p-STAT_1和p-STAT_3的蛋白水平显著上调(P0.05)。与I/R组相比,Pro组和AG490组的血清BUN和Cr浓度、肾组织的MDA含量、AI和肾小管损伤评分降低,SOD活性升高,p-JAK2、p-STAT_1和p-STAT_3蛋白水平显著下调(P0.05)。结论:异丙酚可减轻肝冷缺血再灌注后肾损伤,其机制可能与抑制JAK/STAT信号通路激活有关。     

ARNT基因失活小鼠的肾脏缺血再灌注损伤

背景：如何有效防治肾脏的缺血再灌注损伤,一直是肾移植领域的研究重点。但目前其机制仍然不是很清楚。 目的：探讨缺氧诱导因子系统对小鼠肾缺血再灌注损伤的影响及可能的作用机制。 方法：选取两种小鼠,一种为芳香族碳氢化合物核转移子(aryl hydrocarbon receptor nuclear translocator,ARNT)基因敲除小鼠,一种为同窝对照组小鼠。每种小鼠分别进行假手术、缺血再灌注、缺血再灌注时注射重组人促红细胞生成素、缺血再灌注时注射等量生理盐水。建立小鼠肾脏缺血再灌注损伤模型,分别比较再灌注损伤后1 h血清促红细胞生成素含量、24 h血清肌酐值、肾组织PAS染色肾小管损伤评分和TUNEL法计算肾小管细胞凋亡数。 结果与结论：再灌注后1 h血清促红细胞生成素水平ARNT敲除组明显低于对照组(P < 0.01)。24 h血清肌酐水平ARNT敲除组明显高于对照组(P  < 0.01)。ARNT敲除组明显比对照组损伤程度重,肾小管评分明显高于对照组(P  < 0.01)。ARNT敲除组阳性凋亡细胞数明显多于ARNT+/+组(P < 0.01)。补充促红细胞生成素后,ARNT敲除组与对照组比较,差异无显著性意义(P  > 0.05)。结果表明,缺氧诱导因子系统对肾脏缺血再灌注损伤有重要的保护作用。可能是促红细胞生成素来介导其最大的保护效应。     

远期缺血预适应激活热休克蛋白27、促红细胞生成素、血红素加氧酶1对肾脏缺血再灌注损伤的影响**

背景：缺血再灌注损伤是临床导致急性肾衰竭等其他疾病的重要原因,其机制为多因素、多途径的复杂的病理过程。 目的：观察肾脏进行预处理后激活热休克蛋白、促红细胞生成素和血红素加氧酶1对肾脏缺血再灌注损伤的影响。 方法：雄性C57BL/6小鼠90只随机分成3组。缺血再灌注组为右肾切除,左肾缺血25 min再灌注24 h;预适应组为双侧肾脏缺血20 min再灌注8 d后再进行缺血再灌注。假手术组开腹游离肾蒂。 结果与结论：血清肌酐和尿素氮检测预适应组和假手术组明显低于缺血再灌注组(P < 0.01);MPO染色发现缺血再灌注组大量中性粒细胞浸润(P < 0.01);PAS染色发现预适应组肾组织病理情况轻于缺血再灌注组(P < 0.05);TUNEL染色分析结果表明预适应组和假手术组细胞凋亡数明显少于缺血再灌注组(P < 0.01);预适应组热休克蛋白27 mRNA表达明显高于缺血再灌注和假手术组(P < 0.05),热休克蛋白27 mRNA于第8天时最强,促红细胞生成素、血红素加氧酶1 mRNA在24~    48 h达到峰值A,然后逐渐下降,第8天后达到峰值B,B>A,并且高于假手术组(P < 0.01)。提示远期缺血预适应激活热休克蛋白27、促红细胞生成素、血红素加氧酶1,能减少炎症因子浸润、促进肾小管细胞修复和抑制细胞凋亡从而参与肾脏内源性保护机制。