降钙素基因相关肽和神经生长因子对短暂性全脑缺血后再灌注大鼠纹皮质c-jun mRNA及蛋白表达的影响

目的探讨外源性降钙素基因相关肽（CGRP）和神经生长因子（NGF）对短暂性全脑缺血后再灌注大鼠纹皮质c-jun mRNA及蛋白表达的影响。方法原位杂交和免疫组织化学结合显微图像分析方法。结果假手术组大鼠纹皮质c-jun mRNA表达弱；缺血组较假手术组c-jun mRNA表达显著强（P〈0．01）；CGRP组和NGF组c-jun mRNA表达弱于缺血组（P〈0．05）；CGRP和NGF合用组c-jun mRNA表达明显弱于缺血组（P〈0．01），分别弱于CGRP组和NGF组（P〈0．05）。假手术组大鼠纹皮质未见c-Jun蛋白表达；缺血组较假手术组c-Jun蛋白表达明显强（P〈0．01），缺血后再灌注3h强，1d、3d时弱；CGRP组和NGF组c-Jun蛋白表达较缺血组弱（P〈0．05）；CGRP和NGF合用组较缺血组c-Jun蛋白表达明显弱（P〈0．01），分别弱于CGRP组和NGF组（P〈0．05）；CGRP和NGF合用组缺血后再灌注3h时强，1d、3d时弱。结论CGRP和NGF分别抑制全脑缺血后再灌注大鼠纹皮质c-jun mRNA及蛋白表达，联合应用显著抑制全脑缺血后再灌注大鼠纹皮质c-jun mRNA及蛋白表达，两者对保护缺血神经元可能有协同作用。     

Anti-inflammatory Effect of B-Type Natriuretic Peptide Postconditioning During Myocardial Ischemia–Reperfusion: Involvement of PI3K/Akt Signaling Pathway

High mobility group box 1 protein (HMGB1) plays an important role in myocardial ischemia–reperfusion (I/R) injury. B-type natriuretic peptide (BNP) postconditioning has been reported to reduce myocardial I/R injury. The present study investigated whether postconditioning of BNP could reduce myocardial I/R injury by inhibiting HMGB1 expression and the potential mechanisms in rats. The left anterior descending coronary arteries of rats were occluded to induce ischemia for 30 min and reopened to imitate reperfusion for 4 h. The rats were treated with BNP (0.03 μg/kg min, i.v.) 15 min before reperfusion until the end of the procedure, with or without treatment of LY294002 (an inhibitor of phosphoinositide 3-kinase (PI3K), 0.3 mg/kg, i.v.), which was injected 20 min before reperfusion. Lactate dehydrogenase (LDH), creatine kinase (CK), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and infarct size were measured. Phospho-Akt, total Akt, and HMGB1 expression were assessed by immunoblotting. The results showed that treatment of BNP postconditioning could significantly decrease the infarct size and the levels of LDH and CK after 4-h reperfusion (all p?TNF-α and IL-6 (both p?p?p?PI3K/Akt signaling pathway may be involved in the expression of HMGB1 and the protective effect of BNP postconditioning.     

肾缺血再灌注模型细胞凋亡与吡咯烷二硫代氨基甲酸的干预

背景：肾缺血/再灌注诱导产生大量活性氧,导致核因子κB的活化。激活的核因子κB通过调节诱导型一氧化氮合酶的生成,进而导致一氧化氮的大量产生和触发细胞凋亡。 目的：观察吡咯烷二硫代氨基甲酸对肾缺血再灌注后肾脏组织中核因子κB、诱导型一氧化氮合酶、一氧化氮、caspase-3和细胞凋亡指数的作用。 方法：将健康雄性Wistar大鼠随机分为3组：缺血再灌注组和吡咯烷二硫代氨基甲酸组通过右侧肾切除+左肾动脉夹闭 45 min建立肾缺血/再灌注模型,吡咯烷二硫代氨基甲酸组于实验前30 min尾静脉注射吡咯烷二硫代氨基甲酸 (100 mg/kg)。假手术组不给予缺血再灌注处理。 结果与结论：与假手术组相比,缺血再灌注组大鼠再灌注后肾组织核因子κB表达水平、血肌酐水平、尿素氮水平、诱导型一氧化氮合酶活性、一氧化氮表达水平、caspase-3表达水平和细胞凋亡水平增加(P < 0.05);而与缺血再灌注组相比,吡咯烷二硫代氨基甲酸组大鼠再灌注后以上指标均好转。说明肾缺血/再灌注损伤可引起肾组织结构损伤和细胞凋亡,且与核因子κB引起的一氧化氮高表达有关;应用核因子κB抑制剂吡咯烷二硫代氨基甲酸可对缺血再灌注肾损伤发挥明显的保护作用。     

Protective effect of dapsone against renal ischemia-reperfusion injury in rat

Abstract

Background: Ischemia/reperfusion can cause injury to tissues and compromise functionality of organs due to inflammatory processes. Significantly, development of these effects in kidney tissue has been a challenging issue that leads to acute renal injury. In this study, anti-inflammatory, anti-oxidative, and protective features of dapsone on kidney ischemia/reperfusion injury were investigated.

Material and methods: Renal ischemia was induced in rats by bilateral renal arteries clamping for 45?min followed by 24?h reperfusion phase. The effects of different doses of dapsone (1, 3, 10?mg/kg) on ischemia/reperfusion injury in kidney tissue were investigated by targeting BUN, Creatinine, LDH, MDA, MPO, IL-1β, TNF-α, and NFκB. In addition histopathological examination was performed by H&E staining method.

Results and discussion: Comparing the findings of this study showed significant reduction in BUN and LDH in 10?mg/kg dapsone received groups, and Cr, MDA, and MPO in 3?mg/kg dapsone received groups. The serum level of TNF-α was significantly decreased with both doses of 3 and 10?mg/kg dapsone. The same results were observed in the serum level of IL-1β and NFκB. Besides, remarkable improvement in histological damages was also observed with dapsone treatment.

Conclusion: These results support the hypothesis that the positive effects of dapsone on the renal ischemia/reperfusion injury are mediated by modulating inflammatory cascades.     

Gene silencing of complement C5a receptor using siRNA for preventing ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury in organ transplantation significantly contributes to graft failure and is untreatable using current approaches. I/R injury is associated with activation of the complement system, leading to the release of anaphylatoxins, such as C5a, and the formation of the membrane attack complex. Here, we report a novel therapy for kidney I/R injury through silencing of the C5a receptor (C5aR) gene using siRNA. Mice were injected with 50 μg of C5aR siRNA 2 days before induction of ischemia. Renal ischemia was then induced through clamping of the renal vein and artery of the left kidney for 25 minutes. The therapeutic effects of siRNA on I/R were evaluated by assessment of renal function, histopathology, and inflammatory cytokines. siRNA targeting C5aR efficiently inhibited C5aR gene expression both in vitro and in vivo. Administering C5aR siRNA to mice preserved renal function from I/R injury, as evidenced by reduced levels of serum creatinine and blood urea nitrogen in the treated groups. Inhibition of C5aR also diminished in vivo production of the pro-inflammatory cytokine tumor necrosis factor-α and chemokines MIP-2 and KC, resulting in the reduction of neutrophils influx and cell necrosis in renal tissues. This study demonstrates that siRNA administration represents a novel approach to preventing renal I/R injury and may be used in a variety of clinical settings, including transplantation and acute tubular necrosis.     

Hepatotoxicity and gene expression down-regulation of CYP isozymes caused by renal ischemia/reperfusion in the rat

Renal ischemia/reperfusion (I/R) occurs in many clinical scenarios, including trauma, elective surgery, and transplantation. Events initiated by this process can lead to inflammation in the kidneys, culminating in local injury as well as distant organ dysfunction. The objectives of this study were to investigate the changes in the functions of the liver and the regulation of gene expression of cytochrome P450 (CYP) isozymes after renal I/R. Hepatoxocity was assessed by serum alanine aminotransferase (sALT), serum aspartate aminotransferase (sAST) and liver glutathione-S-transferase (GST) activities, liver glutathione (GSH) level, and histopathological examination. Hepatic cytochrome P4503A1 (CYP3A1) and cytochrome P4502E1 (CYP2E1) activities were measured by erythromycin N-demethylase (ERD) and aniline hydroxylase (ANH) activities, respectively. CYP3A1 and CYP2E1 mRNA expression was determined by RT-PCR. Results showed that activities of sALT and sAST were significantly increased, while hepatic CYP3A1and CYP2E1 activities as well as their respective mRNA levels were significantly decreased after renal I/R. Moreover, hepatic tissue congestion, degeneration, and local necrosis were observed in rats after 1, 4, and 8 h renal reperfusion following 2 h renal ischemia. In conclusion, the present study suggests that renal I/R can cause hepatotoxicity and gene expression down-regulation of CYP isozymes in rats.     

Anti-inflammatory Effects of Valproic Acid in a Rat Model of Renal Ischemia/Reperfusion Injury: Alteration in Cytokine Profile

Valporic acid (VPA) has been implicated to have anti-inflammatory and anti-oxidant activities in several ischemic/reperfusion (I/R) injury models. This study intended to evaluate whether VPA could affect the inflammatory/anti-inflammatory cytokines balance and severity of renal I/R injury in rat. I/R injury was induced in two groups of animals, vehicle normal saline and VPA-treated (IP injection, 150 mg/kg) rats, by 45 min occlusion of both left and right renal arteries followed by 3, 24 and 120 h reperfusion in separate groups. After each time point, kidneys and blood samples were collected for cytokine genes (TNF-α, IL-1β, IL-10 and TGF-β) expression analysis and histological examinations in the kidney tissues. Serum creatinine levels were measured for evaluation of renal function. We observed significantly downregulated mRNA expressions for IL-1β and TNF-α in blood and tissue samples 24 and 120 h post I/R injury in VPA-treated animals compared to control groups (P < 0.0001). On the other hand, mRNA expression levels for IL-10 and TGF-β were significantly increased in the blood samples from VPA-treated animals at two time points after I/R injury (P < 0.0001) and at 120 h in tissue samples (P < 0.001). Histopathology analysis showed downgraded ischemic changes in VPA group compared to sham control. Also, decreased serum creatinine levels were observed in VPA-treated animals particularly 120 h post I/R injury (P < 0.0001) that was correlated with less pathological changes in this group. Our results indicate that VPA can attenuate pro-inflammatory responses and augment the anti-inflammatory condition in favor of faster renal recovery from ischemic changes and improved renal function after renal I/R injury.     

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。     

IL-13对大鼠急性肾缺血再灌注时IL-1β表达的影响

目的:观察IL-13对急性肾缺血再灌注时IL-1β表达的影响。方法:Wistar雄性大鼠57只,随机分为8组:正常组(normal);假手术组(sham);缺血组:(I)缺血再灌注组(I/R);治疗对照组-1(C-1);治疗对照组-2(C-2);治疗组-1(T-1)和治疗组-2(T-2)。阻断大鼠双侧肾脏血流45min再灌注24h建立急性肾缺血再灌注模型;治疗组分别于阻断血流前、后分别从双侧肾动脉开口注射入1.5μg/50gbw鼠重组白细胞介素13(rmIL-13);检测各组大鼠IL-1β血清水平和肾脏表达,以及肾功能和肾脏病理。结果:(1)治疗组肾脏IL-1β基因(TtoC:P＜0.01)和蛋白表达(T-1toC-1:P＜0.01;T-2toC-2:P＜0.05)明显减少,血清IL-1β水平明显下降;(2)肾功能障碍和肾组织病理变化明显减轻,肾小管损害评分减少(C-1toT-1:45.20±8.64to21.05±8.82,P＜0.01;C-2toT-2:42.25±11.15to23.25±7.31,P＜0.01);(3)血清IL-1β水平与BUN、Cr成正相关(r=0.708,P＜0.01;r=0.770,P＜0.01)。结论:IL-13能有效地抑制大鼠急性肾缺血再灌注损伤IL-1β的表达。     

The effects of hepatic ischemia/reperfusion injury on postoperative cognitive function in aged rats

IntroductionHepatic ischemia/reperfusion injury (I/R) is a significant source of morbidity and mortality after liver surgery. The aim of this study was to investigate the effect of hepatic I/R injury on the hippocampus in rats with postoperative cognitive dysfunction (POCD).Material and methodsAdult male Sprague-Dawley rats (n = 160, age: 20–25 months, weight: 300–350 g) received I/R surgery with ischemia for 20 min, 30 min, and 40 min in different groups. Behavior tests of the Morris water maze (MWM) test and the passive avoidance test were applied. Population spike (PS) of pyramidal cells, nuclear factor κB (NF-κB) and protein kinase γ (PKCγ) in the hippocampus were observed.ResultsWithin 10 days after surgery, in aged rats with varying impaired cognitive function, spike size and spike latency period were reduced, level of PKCγ was decreased and an increased level of NF-κB was observed in the I/R group, especially in the I/R group with ischemia for 40 min. The parameters showed no significant difference in rats in the I/R group compared with the sham group at the 18^th day after surgery.ConclusionsHepatic I/R injury has a negative impact on the postoperative cognitive function in aged rats, leading to hippocampus changes with PS abnormity and level changes of NF-κB, PKCγ. However, this cognitive deficit improved over time.     

缺血预处理对肝硬化大鼠肝脏缺血再灌注中肝细胞凋亡的影响

目的:探讨缺血预处理(IPC)在肝硬化大鼠肝缺血再灌注(I/R)损伤的拮抗作用及其机理。方法:Pringle法复制肝I/R模型,将肝硬化大鼠随机分为3组:A组:肝缺血前给予1个IPC处理(缺血5min,灌注5min);B组:肝缺血前给予1个IPC处理(缺血10min,灌注10min);C组:对照组,单纯肝门血流阻断。肝缺血时间为30min,再灌注6h。测定各组的血清谷丙转氨酶(ALT)、肝组织Fas-mRNA表达、caspase-3活性和肝细胞凋亡。结果:经IPC处理后,大鼠7d生存率为100%,而无IPC处理组即为62.5%。再灌注6h,A、B2组的ALT明显低于C组,P＜0.01,A组的ALT亦明显低于B组,P＜0.01。检测A、C2组的肝组织Fas-mRNA表达、caspase-3活性和肝细胞凋亡发现,A组的上述指标均比C组低,P＜0.01。结论:IPC对肝硬化大鼠肝I/R损伤有显著的对抗作用,其中以缺血5min和灌注5min的IPC的作用较强。IPC的保护机理是通过下调Fas-mRNA的表达、抑制caspase-3活性,从而减少肝细胞凋亡来实现的。     

Melatonin attenuates renal ischemia-reperfusion injury in nitric oxide synthase inhibited rats

Recent studies show that melatonin reduces the blood pressure (BP) and ischemia/reperfusion (I/R)-induced damage. This study was designed to investigate the effects of melatonin on the renal I/R injury in rats given the nitric oxide synthase (NOS) inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME). After right nephrectomy, I/R was induced by occlusion of the left renal vessels for 60 min, followed by 24h reperfusion. The administration of melatonin significantly attenuated BP in NOS-inhibited hypertensive rats. Malondialdehyde (MDA) levels, a stable metabolite of the free-radical-mediated lipid peroxidation cascade, were found to be significantly higher in the I/R group (3.48+/-0.2mg/l serum) than in the control group (2.69+/-0.2mg/l serum). L-NAME (40 mgkg(-1) for 15 days)+I/R significantly increased the MDA levels compared to I/R alone. Melatonin administration to L-NAME rats significantly reduced the MDA values resulting from I/R. We also demonstrated that I/R, and especially L-NAME+I/R, lead to structural changes in the kidney and that melatonin attenuates these changes. These results suggest that melatonin reduces BP and I/R injury in NOS inhibited rats by L-NAME.     

白藜芦醇预处理介导Wnt/β-catenin信号通路保护脑缺血再灌注大鼠海马区神经元损伤

目的:研究白藜芦醇(resveratrol,Res)预处理对脑缺血再灌注(ischemia reperfusion,I/R)大鼠海马区Wnt/β-catenin信号通路相关蛋白的表达量、星形胶质细胞及神经元形态的影响,探讨白藜芦醇对脑缺血再灌注大鼠海马区神经元损伤的保护作用机制。方法:将SD大鼠60只随机分为四组,每组15只:正常对照组(Control)、假手术组(Sham)、缺血再灌注组(I/R)和白藜芦醇治疗组(Res)。Res组大鼠连续7 d腹腔注射白藜芦醇(每日30 mg/kg,由2%DMSO溶解),Sham组和I/R组注射同等量2%DMSO;7 d后Res组和I/R组采用改良线栓法制备大鼠大脑中动脉阻塞(middle cerebral artery occlusion,MACO)模型,缺血90 min,再灌注24 h。Sham组仅分离暴露一侧颈内动脉,不插入线栓;24 h后对各组大鼠进行神经功能学评分;脑组织TTC染色;尼氏染色;免疫组化检测海马区GSK-3β和星型胶质细胞(GFAP)数量及形态变化;Western Blot分别检测Wnt信号通路相关因子GSK-3β、p-GSK-3β、β-catenin蛋白水平表达量。结果:再灌注24 h后,尼氏染色显示与I/R组相比Res组海马区仅有少量的神经元破碎和消失,形态尚完整(P0.05),同时行为学评分和梗死面积也低于I/R组(P0.05)。免疫组化显示,与I/R组相比Res组GSK-3β的表达量明显降低,伴随星形胶质细胞活化状态和数量减少(P0.05)。Western Blot显示,与免疫组化表达趋势结果一致Res组GSK-3β的的表达量明显低于I/R组,而p-GSK-3β、β-catenin的表达量均增高(P0.05)。结论:白藜芦醇可能是通过调节Wnt/β-catenin信号通路相关蛋白的表达进而有效的降低大鼠脑缺血再灌注后神经元的损伤。     

Holoturia arenicola extract modulates bile duct ligation-induced oxidative stress in rat kidney

Background: Acute Renal Failure (ARF) in patients with cirrhosis is one of the most frequently encountered complications of obstructive jaundice. Marine organisms from the Mediterranean Coast of Egypt are considered potential sources of bioactive molecules. The present study was undertaken to explore the curative effects of Holothuria arenicola extract (HaE) against renal injury induced by bile duct ligation in male albino rats. Methods: Fifty four male Wistar albino rats were assigned into two main groups, the Sham-operated control (received distilled water only for 28 days) and bile duct ligated (BDL) group, which divided into 2 subgroups, animals of these subgroups treated for 28 consecutive days as follow: Subgroup I (BDL), rats of this subgroup administered distilled water orally. Subgroup II, animals of this subgroup treated orally with HaE (200 mg/kg body weight). Results: BDL induced marked alteration on renal functions as manifested by a significant increase in the kidney function markers, serum creatinine, urea and uric acid. In addition, BDL caused significant increase in MDA level and significant decrease in GSH level as well as antioxidant enzymes activities (GST, SOD and CAT). However, administration of HaE for consecutive 28 days significantly reversed these changes, suggesting that the renal curative effect of HaE against oxidative stress- induced injury might be involved in decreasing lipid peroxide generation and stimulating antioxidant status. Conclusion: The present study revealed that HaE had a profound effect against BDL-induced oxidative stress in the kidney tissues which is the common feature of choestasis in the liver.     

他克莫司对大鼠肾缺血再灌注损伤的影响及其机制的研究

目的: 探讨他克莫司对大鼠肾缺血再灌注(I/R)损伤的保护作用及机制。方法: 将60只健康雄性Wistar大鼠随机分为3组:假手术组、I/R组和他克莫司处理组,每组各4个时点( 0.5 h、2 h、6 h、24 h)。建立肾I/R损伤模型;检测各组大鼠血清肌酐(Cr)、肿瘤坏死因子(TNF-α)、丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性;用光学显微镜观察各组大鼠肾组织病理变化;用免疫组化法检测Fas和caspase-3蛋白的表达。结果: 在相应再灌注各时点,他克莫司处理组血清Cr、TNF-α和MDA水平均低于I/R组(P<0.05),而他克莫司处理组血清SOD活性高于I/R组(P<0.05)。他克莫司处理组肾组织损伤程度明显轻于I/R组。与假手术组比较,I/R组凋亡蛋白Fas和caspase-3表达水平显著增加(P<0.05),而他克莫司处理组凋亡蛋白Fas和caspase-3表达水平则低于I/R组(P<0.05)。结论: 他克莫司能有效抑制I/R引起的自由基产生、肾小管上皮细胞凋亡以及TNF-α水平降低,表明他克莫司对大鼠肾I/R损伤具有保护作用。     

Effect of fentanyl on TNF-alpha and IL-1beta levels during global ischemia/reperfusion in rats

To reduce surgical stress, fentanyl is frequently used for neurosurgical procedures in which focal and/or global ischemia may occur. However, the effect of fentanyl on cytokine levels during ischemia/reperfusion is still uncertain. The goal of this study was to evaluate the effect of fentanyl infusion on levels of the proinflammatory cytokines, tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta, during global cerebral ischemia/reperfusion in rats using the intracerebral microdialysis technique. Forty male Sprague-Dawley rats weighing 280-320 g were randomly assigned to each of four groups: group 1 (no fentanyl infusion and only ischemia/reperfusion); group 2 (1.5 ng/ml of fentanyl infusion during ischemia/reperfusion) and group 3 (3 ng/ml of fentanyl infusion during ischemia/reperfusion) (n=5 in each group). The rats were anesthetized with an intraperitoneal injection of pentobarbital (50 mg/kg). They were then intubated and ventilated with room air using an animal ventilator. A CMA-12 probe was inserted into the left hippocampal CA-1 region according to the guidelines. Artificial cerebrospinal fluid was run from the inserted microdialysis probe and infused with or without fentanyl at 3 microl/min using a microinjection syringe pump during ischemia/reperfusion. Ischemia was induced by clamping the carotid arteries. Hemorrhagic hypotension was induced for 17 min via the femoral artery, and reperfusion was accomplished by unclamping the sling and reinfusing the blood via the femoral artery. After 2 h of stabilization, the microdialysate was collected 10 times every 17 min, just before ischemia (control), after ischemia (I) and after reperfusion (R1-R8), and stored at -80 degrees C until analysis using high-performance liquid chromatography During global ischemia/reperfusion, TNF-alpha and IL-1beta significantly increased at reperfusion (R5) compared with the control value (p < 0.05). However, in both cases of fentanyl infusion, TNF-alpha and IL-1beta showed no increase compared with the control value. Fentanyl inhibited an increase of the proinflammatory cytokines, TNF-alpha and IL-1beta levels, during global cerebral ischemia/reperfusion in rats.     

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.     

IRAK-4活性在脂多糖预处理减轻肝脏缺血再灌注损害中作用的实验研究

目的:观察脂多糖(LPS)预处理后白细胞介素-1受体相关激酶-4（IRAK-4）表达水平在大鼠肝脏缺血再灌注(I/R)早期的变化，探讨LPS预处理减轻肝脏缺血再灌注损害(I/RI)的相关机制。 方法:雄性SD大鼠，随机分为正常对照组，缺血再灌注组(I/R组)和LPS预处理组（LPS组）。正常对照组未予任何处理；LPS组第 1 d 经尾静脉给予脂多糖0.1mg·kg-1，第2、3、4、5 d给予0.5 mg·kg-1；I/R组给予等体积0.5 mL无菌PBS液。第 8 d，建立肝脏缺血再灌注模型。再灌注后0 min、60 min及180 min, 蛋白免疫印记法及逆转录-聚合酶链式反应测定肝组织的IRAK-4蛋白和mRNA表达水平；酶连免疫吸附法检测肝组织NF-κB活性及血清TNF-α含量。 结果:再灌注0 min, IRAK-4蛋白与mRNA表达水平依次为LPS组>I/R组>正常对照组(P<0.01), NF-κB活性以及TNF-α含量LPS组与I/R组差异无显著(P>0.05)，但均高于正常对照组(P<0.01)；再灌注后60 min及180 min，LPS组的IRAK-4蛋白与mRNA表达水平，NF-κB活性以及TNF-α含量却明显低于I/R组（P<0.01）。 结论:抑制IRAK-4表达是LPS预处理减轻肝脏I/RI的重要机制之一。     

Troxerutin Preconditioning and Ischemic Postconditioning Modulate Inflammatory Response after Myocardial Ischemia/Reperfusion Injury in Rat Model

Protective effects of ischemic postconditioning in myocardial ischemia/reperfusion (I/R) injury have been ever demonstrated, but the exact mechanisms remain unclear. Because of their multiplex activities, using natural pharmaceuticals seems to be clinically interesting. The aim of present study was to investigate the effects of troxerutin preconditioning and ischemic postconditioning on inflammatory responses after myocardial I/R injury in a rat model. Twenty-four Wistar rats were divided into four groups as the control, troxerutin receiving (TXR), postconditioning receiving (PostC), and combined therapy (TXR + PostC). Rats’ isolated hearts underwent 30-min LAD regional ischemia followed by 45-min reperfusion. Troxerutin was orally administered for a month before I/R. Ischemic PostC was applied by alternative three cycles of 30-s R/I at the onset of reperfusion. The coronary effluent and ischemic left ventricular samples were used to determine the activities of creatine kinase (CK), intercellular adhesion molecule-1 (ICAM-1), interlukin-1beta (IL-1β), tumor-necrosis factor (TNF-α), and also histopathological studies. Pretreatment of rats with troxerutin significantly reduced myocardial inflammatory cytokines TNF-α and IL-1β levels and ICAM-1 activity after I/R insult compared to those of control I/R hearts (P?<?0.05). Application of PostC showed similar impacts on those parameters. In fact, anti-inflammatory mechanisms of both treatments were associated with their protective effects against myocardial damages causing from I/R injury. Pretreatment with troxerutin as well as postconditioning can induce cardioprotection through prevention of the cell-cell interaction and release of inflammatory mediators, minimizing I/R pathological changes in myocardial cells. These two treatments may share same mechanisms in their actions since they showed no significant additive effects.     

11,12-EET和缺血预处置对在体大鼠正常及再灌注心肌磷酸化ERK和p38MAPK表达的影响

目的:观察11,12-环氧二十碳三烯酸(11,12-EET)和缺血预处置对大鼠再灌注心肌组织磷酸化ERK1/ERK2和p38 MAPK表达的影响,了解大鼠心肌磷酸化ERK1/ERK2和p38 MAPK表达与预处置有否关系。方法: 使用雄性Wistar大鼠,通过结扎(60 min)和松开(30 min)冠状动脉左前降支,复制缺血/再灌注模型;采用缺血5 min,再灌注5 min两次造成缺血预处置。大鼠经手术并静脉给予6.24×10^-8mol/L 11,12-EET,稳定20 min,结扎冠脉复制缺血/再灌注模型。实验分5组:①正常组(norm);②假手术组(sham);③缺血再灌注组(I/R);④短阵缺血预处置组(SI+I/R);⑤11,12-EET预处置缺血/再灌注组(EET+I/R)。采用Western blot法测定心肌细胞外调节的蛋白激酶(ERK1/2)和p38 MAPK的表达程度,并观察再灌注过程中心功能的变化。结果: 再灌注30 min时,I/R组+dp/dt_max%、-dp/dt_max%和LVDP均显著低于sham组、SI+I/R组和EET+I/R组(P＜0.05);而I/R组大鼠心肌ERK1/2磷酸化表达明显高于sham组(P＜0.05),明显低于SI+I/R组和EET+I/R组(P＜0.05);I/R组大鼠心肌p38 MAPK磷酸化表达I/R组显著高于sham组、norm组、SI+I/R及EET+I/R组(P＜0.05)。结论:6.24×10^-8 11,12-EET mol/L具有保护心功能的作用,这种保护作用可能与大量激活磷酸化ERK1/2和抑制p38 MAPK有关。