Anesthetics attenuate ischemia–reperfusion induced renal injury: Effects and mechanisms

Acute kidney injury (AKI) secondary to ischemia–reperfusion injury (IRI) is a major cause of patient morbidity and mortality in the perioperative period. It can lead to new onset of chronic kidney disease and accelerate its progression. Patients with risk factors undergoing cardiac, vascular, and liver transplantation surgeries, which may inevitably involve IRI, are more susceptible to AKI. Anesthetic agents have been postulated to possess renoprotective properties. Thus, exploring the utilization of selective perioperative anesthetic agents with renoprotective properties may be a promising avenue to reduce the risk of AKI. This review discusses the effects and mechanisms of dexmedetomidine, inhalational and intravenous anesthetics, and xenon-mediated renoprotection. Although the renoprotective effects of these agents obtained in the laboratory are promising, much work especially via clinical trials is required to determine the translational value from the bench to the bedside.     

依达拉奉对大鼠心肌缺血再灌注诱发肺损伤的影响

目的 探讨依达拉奉对大鼠心肌缺血再灌注诱发肺损伤的影响.方法 健康清洁级雄性Wistar大鼠24只,体重250～300 g,随机分为4组(n=6):假手术组(S组)、心肌缺血再灌注组(IR组)和不同剂量依达拉奉组(E1组和E2组).IR组、E1组和E2组采用结扎冠状动脉左前降支(LAD)45 min,再灌注3 h的方法制备心肌缺血再灌注模型.S组仅LAD下穿线不结扎;IR组阻断LAD45 min后再灌注3 h;E1组和E2组分别于再灌注前1 min经右股静脉注射依达拉奉3或10 mg/kg.于再灌注3 h时放血处死大鼠,取肺组织、支气管肺泡灌洗液和动脉血样,测定血清肌酸激酶同工酶(CK-MB)活性,计算肺通透性指数(PPI),采用Western blot法检测肺组织β-防御素-2(BD-2)和TNF-α蛋白的表达,PCR法测定肺组织BD-2 mRNA表达.结果 与S组比较,IR组、E1组和E2组血清CK-MB活性和PPI升高,肺组织BD-2 mRNA、BD-2和TNF-α蛋白表达上调(P＜0.01).与IR组比较,E1组和E2组血清CK-MB活性和PPI降低,肺组织BD-2 mRNA、BD-2和TNF-α蛋白表达下调(P＜0.01).与E1组比较,E2组血清CK-MB活性和PPI降低,肺组织BD-2 mRNA、BD-2和TNF-α蛋白表达下调(P＜0.01).结论 依达拉奉可减轻大鼠心肌缺血再灌注诱发的肺损伤,其机制不仅与清除氧自由基有关,还与抑制肺组织炎性反应有关.     

Hypoxia-inducible factor prolyl hydroxylase inhibitor roxadustat (FG-4592) protects against renal ischemia/reperfusion injury by inhibiting inflammation

Hypoxia-induced inflammation is the critical pathological feature of acute kidney injury (AKI). Activation of hypoxia-inducible factor (HIF) signaling is considered as a central mechanism of body adapting to hypoxia. Hypoxia-inducible factor prolyl hydroxylase inhibitor FG-4592 (Roxadustat) is a first-in-class HIF stabilizer for the treatment of patients with renal anemia. The current study aimed to investigate whether FG-4592 could protect against ischemia/reperfusion (I/R)-induced kidney injury via inhibiting inflammation. Here, efficacy of FG-4592 was evaluated in a mice model of I/R-induced AKI. Interestingly, improved renal function and renal tubular injuries, combined with reduced kidney injury molecule-1 were observed in the mice with FG-4592 administration. Meanwhile, inflammation responses in FG-4592-treated mice were also strikingly attenuated, as evidenced by the decreased infiltration of macrophages and neutrophils and down-regulated expression of inflammatory cytokines. In vitro, FG-4592 treatment significantly protected the tubular epithelial cells against hypoxia-induced injury, with suppressed inflammation and cell injuries. In summary, FG-4592 treatment could protect against the I/R-induced kidney injury possibly through diminishing tubular cells injuries and suppression of sequence inflammatory responses. Thus, our findings definitely offered a clinical potential approach in treating AKI.     

Inhibition of nitric oxide synthase reduces renal ischemia/reperfusion injury

BACKGROUND: The role of nitric oxide (NO) production because of inducible nitric oxide synthase (iNOS) in the pathogenesis of renal ischemia/reperfusion (I/R) injury is unclear. In this study the roles of both iNOS and NO were characterized in a rat model of renal I/R injury. In addition, the effect of iNOS inhibition on renal function was evaluated. METHODS: Sprague-Dawley rats underwent 45 min of left renal ischemia and contralateral nephrectomy followed by various periods of reperfusion and renal function analysis [plasma creatinine, fractional excretion of sodium (FENa), creatinine clearance (CrCl), and measurement of plasma and urine NO levels]. In addition, the effect of treatment with 1400W, a highly selective iNOS inhibitor, was evaluated. RESULTS: Renal dysfunction peaked at 48 h after reperfusion and immunohistochemistry studies revealed iNOS expression in the vasculature (3 h) and renal tubules (48 h) after reperfusion. Renal function improved significantly in treated animals compared to controls [creatinine of 1.1 v. 1.9 mg/dl (P < 0.05) and CrCl of 0.54 v. 0.31 ml/min (P < 0.05), respectively]. In addition, FENa was decreased by 50%, plasma NO levels were significantly lower (32.7 v. 45.7 micromol/L, P < 0.01), and deposition of nitrotyosine in the tubules of treated rats was less than in control animals. CONCLUSIONS: These data support the hypothesis that iNOS and NO are involved in the pathogenesis of renal I/R injury and suggests that use of iNOS inhibitors may be a valuable therapeutic strategy clinical situations where renal I/R may be prevalent.     

左卡尼汀对肾缺血再灌注损伤的抗氧化作用及其机制

目的研究左卡尼汀对大鼠肾缺血再灌注损伤的抗氧化作用并探讨其机制。方法将大鼠随机分为3组：对照组（C组）,缺血再灌注组（IR组）,左卡尼汀组（LC组）。C组不予缺血再灌注处理,IR组及LC组建立肾脏IR模型。再灌注6h后检测各组血清肌酐（Cr）和尿素氮（BUN）水平;测定肾组织超氧化物歧化酶（SOD）活性及丙二醛（MDA）含量;RT-PCR检测肾组织核因子E2相关因子2（Nrf2）、血红素氧化酶-1（HO-1）mRNA含量;Western-blot检测各组肾组织Nrf2及HO-1蛋白表达水平。结果 LC组血清Cr、BUN水平低于IR组[（74.17±12.80）μmol/L、（24.28±2.58）mmol/L vs.（112.83±17.45）μmol/L、（35.13±6.01）mmol/L],差异具有统计学意义（P〈0.01）。LC组肾组织SOD活性高于IR组[（39.55±6.61）kU/g vs.（28.05±4.37）kU/g],差异具有统计学意义（P〈0.01）;MDA显著降低于IR组[（4.15±0.69）μmol/g vs.（6.12±1.08）μmol/g],差异具有统计学意义（P〈0.01）。IR组Nrf2、HO-1mRNA及蛋白表达水平高于C组（P〈0.01）,低于LC组（P〈0.01）。结论左卡尼汀对肾脏缺血再灌注损伤具有明显保护作用,其机制可能为激活Keapl-Nrf2-ARE通路进而诱导HO-1的表达。     

β-hydroxybutyrate attenuates renal ischemia-reperfusion injury through its anti-pyroptotic effects

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瘦素在肝缺血/再灌注致肾损伤中作用的研究

目的：研究瘦素（Leptin）在肝缺血/再灌注（I/R）后肾组织中的表达变化,探讨其与肝I/R介导的肾损伤的关系。方法：建立大鼠70%肝I/R模型,设立假手术和缺血60min后再灌注60、150、240、360min组,观察肾脏的病理学变化,检测各组血清尿酸、总抗氧化能力,肾Leptin蛋白及其mRNA表达的变化。结果：与假手术组比较,缺血60min/再灌注150min及再灌注240min组血清尿酸显著升高,以再灌注240min升高最为显著;再灌注240min和360min组血清总抗氧化能力显著升高,以再灌注240min升高最为显著;再灌注150、240和360min组肾Leptin蛋白表达显著升高,再灌注60、240、360min组肾LeptinmRNA表达显著升高,而再灌注150min组LeptinmRNA显著降低。病理学观察提示肝I/R早期的肾损伤较重而后期显著减轻。结论：Leptin在肝I/R后肾组织内的表达变化与肾损伤密切相关,提示它可能作为一种保护因子对抗肝I/R介导的肾损伤。     

低温环境复灌对兔肾缺血-再灌注损伤保护作用的实验研究

目的  探讨建立兔肾缺血低温环境、常温环境及高温环境再灌注损伤模型的新方法, 并评价低温环境复灌对兔肾缺血-再灌注损伤(IRI)的影响。方法  将60只健康新西兰兔随机分为5组:对照组(A组)、假手术组(B组)、低温环境复灌组(C组)、常温环境复灌组(D组)、高温环境复灌组(E组), 每组12只。术后7 d内每日检测各组兔的血清肌酐(Scr)、血尿素氮(BUN)水平; 术后1 d检测各组兔肾组织内丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性; 术后1 d采用苏木素-伊红(HE)染色观察肾组织病理学变化; 术后1 d采用dUTP缺口末端标记(TUNEL)染色评价细胞凋亡。结果  术后1 d, 与A组和B组比较, C、D和E组兔的Scr和BUN水平均升高(均为P < 0.01);与C组比较, D组和E组兔的Scr和BUN水平升高更明显(均为P < 0.05)。术后7 d内, C、D和E组兔的Scr和BUN水平呈下降趋势。与D组和E组比较, C组兔的Scr和BUN水平较低(均为P < 0.05)。与A组和B组比较, C、D和E组的MDA含量均升高, SOD活性均降低(均为P < 0.01);与C组比较, D组和E组的MDA含量升高更明显, SOD活性更低(均为P < 0.01)。术后1 d肾组织病理学检查示A组和B组肾组织形态结构正常, D组和E组损伤表现明显, 与D、E组比较, C组损伤较轻。TUNEL染色结果显示, D组和E组肾小管上皮细胞阳性细胞明显增多, 管腔内也可见到阳性细胞, C组阳性细胞数量较D组和E组明显减少。结论  冰泥覆盖肾脏、37 ℃生理盐水及40 ℃生理盐水连续滴加肾脏可建立不同温度环境复灌模型。低温环境复灌对肾IRI具有保护作用。     

p38MAPK、MMP-2在大鼠肾缺血再灌注损伤早期的表达及影响

目的：探讨p38MAPK、MMP-2在大鼠肾缺血再灌注后早期的表达情况及其在。肾缺血再灌注损伤中的作用。方法：选择健康雄性SD大鼠48只,随机分成假手术（sham）组24只,缺血再灌注（IR）组24只,建立大鼠肾缺血再灌注损伤模型,测定各组实验大鼠血清肌酐水平的变化,应用免疫组织化学二步法检测p38MAPK、MMP-2表达的变化。结果：与sham组比较,IR组血清肌酐水平升高,缺血45分钟再灌注24小时达高峰（P〈0．01）。MMP-2蛋白在sham组呈少量散在表达或不表达,缺血45分钟再灌注6小时有少量表达,再灌注12小时、24小时及72小时呈阳性表达,以24小时达高峰（P〈0．05）;p38MAPK蛋白在sham组呈少量散在表达或不表达,缺血45分钟再灌注6小时、12小时及24小时呈阳性表达,12小时达高峰（P〈0．05）。p38MAPK、MMP-2蛋白的表达与血清肌酐水平的变化呈显著正相关。结论：肾缺血再灌注可激活p38MAPK,活化的p38MAPK可以上调MMP-2蛋白的表达,可能促进了肾缺血再灌注损伤的发生和发展。     

七氟烷对脑缺血/再灌注损伤的保护机制

七氟烷可能通过类似于缺血预处理的机制、减少兴奋性氨基酸和单胺类递质释放、抑制神经元的凋亡、抑制脑代谢和调节体温等机制对脑缺血／再灌注损伤发挥保护作用。     

Protective effects of propofol against ischemia/reperfusion injury in rat kidneys

Aim: The purpose of this study was to investigate and compare the efficiency of propofol in the reduction of injury induced by free radicals in a rat model of renal ischemia/reperfusion (I/R). Method: Twenty-four Wistar rats were divided into four groups in our study. Rats in the sham group underwent laparotomy and were made to wait for 120 min without ischemia. Rats in the control group were given nothing with ischemia–reperfusion. Rats in the I/R groups were given propofol (25 mg/kg) and 10% intralipid (250 mg/kg) ip, respectively, 15 min before the ischemia for 60 min followed by reperfusion for 60 min. The kidney tissues of the rats were taken under anesthesia at the end of the reperfusion period. Evaluation of biochemical malondialdehyde (MDA), superoxide dismutase, and catalase activities and histopathological analysis were performed with these samples. Results: I/R significantly increased MDA levels (p < 0.05). Histopathological findings of the control group confirmed that there was renal impairment by tubular cell swelling, interstitial edema, medullary congestion, and tubular dilatation. MDA levels were lower in the propofol group compared to control group (p < 0.05). In the propofol group, the level of histopathological scores is significantly decreased than control and intralipid groups in ischemia–reperfusion. Conclusion: Our results demonstrate that I/R injury was significantly reduced in the presence of propofol. The protective effects of propofol may be due to their antioxidant properties. These results may indicate that propofol anesthesia protects against functional, biochemical, and morphological damage better than control in renal I/R injury.     

Renal ischemia/reperfusion against nephrectomy for induction of acute lung injury in rats

Purpose: Acute kidney injury (AKI) induces acute lung injury (ALI) through releasing injurious mediators or impairing clearance of systemic factors. To determine the links between AKI and ALI, pulmonary and blood variables were evaluated following induction of AKI via different experimental models of bilateral renal ischemia/reperfusion (BIR: renal ischemia with uremia), unilateral renal ischemia/reperfusion (UIR: renal ischemia without uremia), bilateral nephrectomy (BNX: uremia without renal ischemia), and unilateral nephrectomy (UNX: without uremia and renal ischemia).

Methods: Ninety male Sprague–Dawley rats were divided into six groups. Animals had 1-h bilateral or 2-h unilateral renal ischemia followed by 24-h reperfusion in the BIR and UIR groups, respectively, and 24-h period following bilateral or unilateral nephrectomy in the BNX and UNX groups, respectively. There were also sham and control groups with and without sham-operation, respectively.

Results: Plasma malondialdehyde and nitric oxide were elevated by BIR more than UIR, but not changed by UNX and BNX. UIR slightly increased plasma creatinine, whereas BIR and BNX largely increased plasma creatinine, urea, K^+?and osmolality and decreased arterial HCO₃^?, pH, and CO₂. UNX and UIR did not affect lung, but BIR and BNX induced ALI with equal capillary leak and macrophages infiltration. However, there were more prominent lung edema and vascular congestion following BNX and more severe neutrophils infiltration and P_aO₂/F_iO₂ reduction following BIR.

Conclusion: Acutely accumulated systemic mediators following renal failure in the absence of kidneys vary from those due to combined renal failure with ischemic-reperfused kidneys and consequently they induce ALI with distinct characteristics.     

The role of interleukin-18 in renal injury

Interleukin (IL)-18 is a relatively new pro-inflammatory cytokine, formerly known as interferon-gamma-inducing factor, which induces interferon-gamma production in T cells and natural killer cells. It is synthesized as a biologically inactive precursor, which requires cleavage into an active molecule by an intracellular cysteine protease similar to IL-1beta. This review examines the pro-inflammatory role of IL-18 in various types of renal injury (i.e., endotoxemia, cisplatin toxicity, allograft rejection, and ischemia-reperfusion injury) and explores the integral role of IL-12 in IL-18 function and activity.     

Protective role of dehydroascorbate in rat liver ischemia-reperfusion injury

BACKGROUND: Oxidative stress plays an important role in liver ischemia/reperfusion (I/R) injury. Thus, enhancing the liver antioxidant capacity could be a promising therapeutic strategy. Ascorbate (AA) is considered the perfect antioxidant, but its therapeutic efficacy is greatly limited by its slow achievement of high intracellular levels. This might be circumvented by administering dehydroascorbate (DHA), which presents a several-fold greater uptake than AA, and undergoes rapid intracellular reduction to AA. Thus, our aim was to assess the protective role of DHA in liver I/R injury. MATERIALS AND METHODS: Wistar rats (200-300 g bw) were pretreated iv with different doses of AA or DHA 20 min before liver ischemia, followed by 6 h reperfusion. Liver damage was assessed by biochemical and morphological indices. RESULTS: DHA pretreatment induced a rapid increase in liver ascorbate levels, significantly higher than findings for AA, without any significant reduction in glutathione levels. Liver damage during I/R in controls showed significant increases in serum transaminases and hepatic thiobarbituric acid reactive substances with alterations of liver morphology. DHA administration induced a clear, significant protection against I/R injury, whereas liver damage was only moderately prevented by AA. CONCLUSIONS: DHA might represent a simple, effective therapeutic option to prevent liver damage associated with ischemia/reperfusion.     

Effect of apigenin on apoptosis induced by renal ischemia/reperfusion injury in vivo and in vitro

Objectives: This study aims to investigate the effects and molecular mechanisms of apigenin (ApI) on renal ischemia/reperfusion (I/R) injury in vivo and in vitro.

Methods: In vivo, the left renal artery was clamped for 45?min and the right kidney was removed to study renal I/R injury on Sprague-Dawley (SD) rats. ApI was injected at 60?min before renal ischemia. In vitro, renal tubular epithelial cells (HK-2) were pretreated with or without ApI (20 uM) for 60?min and then treated with hypoxia/reoxygenation (H/R). Renal function, histology, cells apoptosis, and cell viability were tested. Furthermore, the potential molecular mechanisms were assessed.

Results: ApI pretreatment could significantly alleviated the renal function and the pathological damage as well as cells apoptosis after I/R injury. Meanwhile, ApI treatment protects H/R induced HK-2 cell apoptosis in vitro. The results of Western blot showed that ApI significantly increased the expressions of B-cell lymphoma 2 (Bcl-2) and phosphor-AKt (p-AKt), Phosphoinositide 3-kinase (PI3K), while down-regulated the expressions of Caspase3 and Bax induced by H/R injury.

Conclusions: ApI pretreatment can protect renal function against I/R injury and prevent renal tubular cells from apoptosis in vivo and in vitro which might through PI3K/Akt mediated mitochondria-dependent apoptosis signaling pathway.     

羟考酮预给药对大鼠肾缺血-再灌注损伤的影响

目的评价羟考酮预给药对大鼠肾缺血-再灌注损伤的影响。方法健康成年雄性SD大鼠30只,采用随机数字表法,将其分为三组(n=10),假手术组(S组):仅切除右肾、分离左侧肾动脉、肾静脉和输尿管;缺血-再灌注组(IR组):切除右侧肾脏,夹闭左侧肾动脉和肾静脉45min恢复灌注2h;羟考酮预给药+缺血-再灌注组(O组):缺血-再灌注前5min静脉注射羟考酮2mg/kg。于再灌注2h时经腹主动脉采集动脉血样,血清尿素氮(BUN)浓度采用脲酶法测定,血清肌酐(Cr)浓度采用速率法测定。处死大鼠,取部分左肾组织,超氧化物歧化酶(SOD)活性采用黄嘌呤氧化酶法测定,丙二醛(MDA)含量采用硫代巴比妥酸法测定。采用Western blot检测肾组织中B细胞淋巴瘤/白血病-2(bcl-2)、B细胞淋巴瘤/白血病-2相关x蛋白(bax)、半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)蛋白表达。结果与S组比较,IR组和O组血清BUN和Cr的浓度明显升高(P0.05),肾组织MDA的含量明显升高,SOD活性明显降低(P0.05),肾组织bax、Caspase-3蛋白表达明显升高(P0.05),而bcl-2蛋白表达明显降低(P0.05)。与IR组比较,O组血清BUN和Cr的浓度明显降低(P0.05),肾组织MDA的含量明显降低,SOD活性明显升高(P0.05)肾组织bax、Caspase-3蛋白表达明显降低(P0.05),而bcl-2蛋白表达明显升高(P0.05)。结论羟考酮预给药可减轻大鼠肾缺血-再灌注损伤,其机制可能与其抑制肾组织氧化应激反应和细胞凋亡有关。     

Prevention of reperfusion injury of the spinal cord in aortic surgery: An experimental study

Purpose We designed an experimental study to show the effects of some agents in order to prevent reperfusion injury of the spinal cord. Methods Twenty rabbits were used and were divided into two groups in our study. Infrarenal abdominal aortic occlusion, between renal arteries and iliac bifurcations, was applied to the subjects in group 1 for only 30 min; in the group 2 subjects, on the other hand, intra-aortic diltiazem, N-acetylcysteine, and catalase combinations were applied after infrarenal abdominal aortic occlusion. The spinal cord functions of the subjects were assessed at the 48th hour after the operation according to Tarlov scoring, then cord tissue samples were taken for biochemical and histopathological studies. Results The group 2 subjects had better neurological functions than group 1 subjects (P < 0.01). In group 2; superoxide dismutase and glutathione peroxidase levels increased, while malondialdehyde and xanthine oxidase levels decreased as compared with group 1 (P < 0.05). A histopathological examination showed the group 2 samples to have fewer bleeding points and less neuron loss. Conclusions We concluded that antioxidant agent combinations (diltiazem, N-acetylcysteine, and catalase) applied after ischemia might thus help protect the spinal cord against ischemia and reperfusion injury.     

红景天甙对大鼠肾脏缺血再灌注损伤的保护作用

目的探讨红景天甙对大鼠肾脏缺血再灌注损伤（IRI）的预防和保护作用。方法将32只健康成年SD大鼠随机分成正常对照组、假手术组、缺血再灌注组和红景天甙组4组，每组8只。缺血再灌注组和红景天甙组分别制作肾脏缺血再灌注模型，红景天甙组予以红景天甙预处理。检测血中尿素氮（BUN）和肌酐（Scr）及肾脏中超氧化物歧化酶（SOD）、丙二酰二醛（MDA）和钠钾ATP酶（Na^＋-K^＋ATPase）含量，并用光镜和电镜观察肾脏组织形态学变化。结果红景天甙组血清BUN和Scr水平、肾皮质MDA含量较缺血再灌注组显著降低（P〈0．01），而肾皮质中SOD和Na^＋-K^＋ATPase含量与缺血再灌注组相比显著升高（P〈0．01）；肾组织光镜和电镜观察均见缺血再灌注组肾小球和肾小管上皮细胞损伤明显，而红景天甙组肾小球及肾小管仅见轻微损伤。结论红景天甙能有效降低大鼠肾脏缺血再灌注损伤（IRI），对肾脏IRI有明显的预防和保护作用，为临床上肾脏IRI提供新的预防和治疗思路。