Ameliorative Effects of Proanthocyanidin on Renal Ischemia/Reperfusion Injury

Introduction. Several natural products have been reported to have beneficial effects on ischemia/reperfusion (I/R) injury, particularly from a preventative perspective. Therefore, this study was designed to investigate the efficiency of proanthocyanidin (PA), a natural product derived from grape seed, on renal dysfunction and injury induced by I/R of rat kidney. Materials and Methods. Twenty-four male Sprague-Dawley rats were divided into three groups: sham-operated, I/R, I/R+PA. Rats were given PA (100 mg/kg/day peroral) 7 days prior to I/R. All rats except sham-operated underwent 60 min of bilateral renal ischemia followed by 6 h of reperfusion. After reperfusion, kidneys and blood were obtained for evaluation. Superoxide dismutase, glutathione peroxidase, malondialdehyde, protein carbonyl content, and nitrite/nitrate level (NO_x) were determined in the renal tissue. Serum creatinine (S_Cr), blood urea nitrogen (BUN), and aspartate aminotransferase (AST) were determined in the blood. Additionally, renal sections were used for histological grade of renal injury. Results. PA significantly reduced the I/R-induced increases in S_Cr, BUN, and AST. In addition, PA markedly reduced elevated oxidative stress product, restored decreased antioxidant enzymes, and attenuated histological alterations. Moreover, PA attenuated the tissue NO_x, levels indicating reduced NO production. Conclusions. The pretreatment of rats with PA reduced the renal dysfunction and morphological changes, ameliorated cellular injury, and restored renal antioxidant enzymes caused by renal I/R.     

己酮可可碱在肺缺血-再灌注损伤中的作用

目的　探讨己酮可可碱 (PTX)对肺缺血 -再灌注损伤的保护作用。　方法　 72只大鼠随机分为 3组 ,每组 2 4只。 组 :未行缺血及再灌注处理 ; 组 :行左肺缺血和再灌注处理 ; 组 :行左肺缺血和再灌注处理 ,并给予己酮可可碱。采用在体肺温缺血 -再灌注损伤的模型 ,于缺血 45分钟、再灌注 1小时、2小时和 4小时进行动脉血气分析、肺组织含水量、支气管肺泡灌洗液白蛋白含量、血浆和左肺组织丙二醛、左肺组织和支气管肺泡灌洗液髓过氧化物酶(MPO)活性测定。　结果　 组再灌注 2小时和 4小时动脉血氧分压显著降低 ,各时间点左肺含水量、支气管肺泡灌洗液白蛋白含量、血浆丙二醛、左肺组织、支气管肺泡灌洗液中髓过氧化物酶均显著升高 ,PTX可改善上述指标变化。结论　 PTX通过抑制中性粒细胞肺内聚集 ,减轻肺血管内皮细胞损伤程度 ,而防止损伤的发展     

The Effects of Medical Ozone Therapy on Renal Ischemia/Reperfusion Injury

Introduction: This study was designed to investigate the possible beneficial effects of medical ozone therapy (OT), known as an immunomodulator and antioxidant, on the renal function, morphology, and biochemical parameters of oxidative stress in kidneys subjected to ischemia/reperfusion injury (IRI). Materials and methods: Thirty male Sprague–Dawley rats were classified into three groups: control, renal IRI, and renal IRI + OT. The IRI group was induced by bilateral renal ischemia for 60 min, followed by reperfusion for 6 h. After reperfusion, the kidneys and blood of rats were obtained for histopathologic and biochemical evaluation. Results: Renal IRI increased the tissue oxidative stress parameters (lipid peroxidation, protein oxidation, and nitrite plus nitrate) and decreased the antioxidant enzyme activities (superoxide dismutase and glutathione peroxidase). The serum neopterin levels showed correlation with oxidative stress parameters. All these parameters were brought to control values in the treatment group. Histopathologically, the kidney injury in the treatment group was significantly lesser than in the renal IRI group. Conclusions: Our results clearly showed that OT has beneficial effect to protect kidney against IRI. The serum neopterin levels might be used as a marker to detect the degree of renal IRI.     

Beneficial Effects of N-Acetylcysteine and Ebselen on Renal Ischemia/Reperfusion Injury

Abstract

Introduction: It has been demonstrated that peroxynitrite accompanies acute renal ischemia and contributes to the pathophysiology of renal damage. Therefore, we aimed to investigate the roles of N-acetylcysteine (NAC), a well-known powerful antioxidant, and ebselen (E), a scavenger of peroxynitrite, on renal injury induced by renal ischemia/reperfusion injury (IRI) of rat kidney. Materials and methods: Forty male Sprague–Dawley rats were divided into five groups: sham, renal IRI, renal IRI+NAC, renal IRI+E, and renal IRI+NAC+E. IR injury was induced by 60 min of bilateral renal ischemia followed by 6 h of reperfusion. After reperfusion, kidneys and blood samples were obtained for histopathological and biochemical evaluations. Results: Renal IR resulted in increased malondialdehyde and nitrite/nitrate levels suggesting increased lipid peroxidation and peroxynitrite production and decreased superoxide dismutase and glutathione peroxidase activities. Both NAC and E alone significantly decreased malondialdehyde and nitrite/nitrate levels and increased superoxide dismutase and glutathione peroxidase activities. Additionally in the renal IRI+NAC+E group, all biochemical results were quite close to those of sham group. Histopathologically, the kidney injury in rats treated with combination of NAC and E was found significantly less than the other groups. Conclusions: Both NAC and E are able to ameliorate IRI of the kidney by decreasing oxidative and nitrosative stresses and increasing free radical scavenger properties. Additionally, combination of NAC and E prevents kidney damage more than when each drug is used alone, suggesting that scavenging peroxynitrite nearby antioxidant activity is important in preventing renal IRI.     

Oxidized LDL Accumulation in Experimental Renal Ischemia Reperfusion Injury Model

Background/Aims. The aim of this study was to identify oxidative damage of kidney during ischemia reperfusion injury (IRI) by evaluating changes in lipid peroxidation markers in tissue and blood by an experimental model. Oxidized LDL (ox-LDL) was used as an oxidative stress biomarker, whereas paraoxonase (PON-1) activity was used as an antioxidative biomarker. Methods. Sixty-three male Wistar rats were randomly assigned into three groups: renal IRI, sham, and control. In the renal IRI group, the right kidney was removed and the artery and vein of the left kidney were clamped for 90 minutes. The presence of ox-LDL in the kidney tissue sections was determined by using an immunofluorescent staining method. Results. The plasma ox-LDL levels did not increase significantly at the 24^th hour following IRI, made a peak at the 48^th hour, and declined at the 72^nd hour. Accumulation of ox-LDL was detected in the kidney tissue on the 24^th, 48^th, and 72^nd hours of the renal IRI. Serum PON-1 levels have peaked on the 24^th hour and then declined. Conclusion. This study demonstrates the accumulation of ox-LDL molecules in the renal tissues of the IRI model. Future strategies aimed to reduce the lipid peroxidation during the initial hours of renal IRI may be useful to prevent complications of ischemia.     

人参皂甙Rb1对肺缺血再灌注损伤的保护作用

目的探讨人参皂甙Ｒｂ１对肺缺血再灌注损伤的保护作用。方法按肺移植供肺获取和保存的方法，对３５只家兔的肺分别获取，保存；然后采用体外装置，建立体外肺缺血再灌注损伤模型。在即将再灌流前，将不同剂量的Ｒｂ１加入到５０ｍｌ再灌流血液中。结果Ｒｂ１可使肺组织中超氧化物歧化酶（ＳＯＤ）含量升高，丙二醛（ＭＤＡ）含量降低；使肺动脉压（ＰＡＰ）降低，湿肺干肺比重降低和改善肺组织病理变化。Ｒｂ１在再灌流血液中浓度为８０ｍｇ／Ｌ时，已有明显效果。结论Ｒｂ１对肺缺血再灌注损伤具有明显的保护作用。     

茶多酚对大鼠肾缺血再灌注损伤的保护作用

目的：探讨茶多酚（teapolyphenols,TP）预处理对大鼠肾缺血再灌注损伤（ischemia reperfusion injury,IRI）的保护作用及其机制。方法：雄性SD大鼠42只,随机分为假手术组、IRI组和TP预处理组。IRI组及TP组手术建立肾IRI模型,TP预处理组在此基础上加用TP治疗。IRI组及TP预处理组在缺血1h恢复灌注开始时刻、2h后、24h后分别检测血清肌酐（Scr）、血清超氧化物岐化酶（SOD）、血清丙二醛（MDA）、肾组织SOD和肾组织MDA水平,并观察肾组织的病理变化。结果：TP预处理组肾组织病理变化轻于IRI组;与假手术组相比较,IRI组的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TP预处理组的Scr、MDA和肾组织的MDA均比IRI组低（P〈0.05）,而血清SOD水平及肾组织中的SOD水平升高（P〈0.05）。结论：TP对肾脏缺血再灌注损伤具有保护作用,其机制可能是通过抗氧化作用实现的。     

葡天胶囊对大鼠肾脏缺血再灌注损伤的保护作用

目的：探讨葡天胶囊预处理对大鼠肾脏缺血再灌注损伤的保护作用。方法：雄性Wistar大鼠24只,随机分为假手术组（Sham组）、模型对照组（Control组）、葡天胶囊预处理组（PT组）,每组各8只。模型对照组及葡天胶囊160mg·kg^-1·d^-1预处理组手术建立肾脏缺血再灌注模型,缺血后1h恢复灌注,分别在恢复灌注后24h、48h、72h后检测血肌酐、尿素氮及血清白蛋白水平,并观察肾脏病理变化。结果：与假手术组相比,模型组血肌酐水平升高（P〈0.05）;葡天胶囊预处理组再灌24h、48h及72h血肌酐水平明显低于模型组（P〈0.05）;肾脏病理显示葡天胶囊预处理组肾组织病变轻于模型对照组。结论：葡天胶囊对肾脏缺血再灌注损伤有保护作用,具有一定的临床应用价值。     

新霉素对脑缺血再灌注损伤的保护作用

目的：探讨钙及磷酯酶Ｃ（ＰＬＣ）在脑缺血再灌注损伤中的作用机制及ＰＬＣ抑制剂新霉素是否通过抑制ＰＬＣ活性而起脑保护作用。方法：和放血降压法建立大鼠全脑缺血模型，采用原子吸收光谱法及干湿法测定缺血再灌注后脑组织含钙量。含水量变化及新霉素对其影响。结果：再灌组含钙量、含水量较对照组升高（Ｐ〈０．０５）；再灌组内随灌注时间延长，脑组织含钙量、含水量增高（Ｐ〈０．０５）；给药组含钙量、含水量均较再灌组降低     

Caffeic Acid Phenethyl Ester Alleviates Mesenteric Ischemia/Reperfusion Injury

ABSTRACT

Purpose: We aimed to investigate the effects of caffeic acid phenethyl ester (CAPE) on intestinal mucosal injury induced by superior mesenteric occlusion. Methods: This experimental study was conducted on 48 male Wistar-albino rats. The animals were randomly allocated into four groups: (i) Sham-operated group, laparotomy without intestinal ischemia/reperfusion (IR) injury (n = 12); (ii) Sham + CAPE group, identical to group 1 except for CAPE treatment (10 μmol/kg, intravenously) (n = 12); (iii) Intestinal IR group, 60 min of superior mesenteric ischemia followed by 3 hr of reperfusion (n = 12); and (iv) (IR + CAPE)-treated group, 10 μmol/kg injection of CAPE intravenously 30 min before the reperfusion period (n = 12). We evaluated the degree of intestinal mucosal injury on a grading scale, histopathologically, and by measuring oxidative stress markers and antioxidant parameters, biochemically. Intestinal edema was estimated by using wet/dry weight ratios. The plasma proinflammatory cytokine levels were measured. Animal survival was observed up to one week. Results: Intestinal mucosal injury scores were significantly decreased with CAPE administration (p < .05). CAPE treatment significantly reduced oxidative stress markers in the intestinal tissues (p < .05) and the plasma proinflammatory cytokine levels (p < .05), and significantly increased antioxidant parameters in the intestinal tissues (p < .05). Intestinal edema was significantly alleviated by CAPE treatment (p < .05). The survival rates of CAPE-treated IR animals were significantly higher than IR-subjected rats (p < .05). Conclusion: This study clearly showed that CAPE treatment significantly alleviated the intestinal mucosal injury caused by superior mesenteric ischemia/reperfusion. Further clinical studies are required to clarify whether CAPE has a useful role in reperfusion injury during particular surgeries in which IR-induced organ injury occurs.     

Scavenging of Peroxynitrite Reduces Renal Ischemia/Reperfusion Injury

Introduction. Nitric oxide (NO) and peroxynitrite (OONO—) are implicated in the pathophysiology of renal ischemia/reperfusion (I/R). The aim of this study was to investigate and compare the efficiency of S-methylisothiourea (SMT), an iNOS inhibitor, and mercaptoethylguanidine (MEG), a scavenger of peroxynitrite, on renal dysfunction and injury induced by I/R of rat kidney. Materials and Methods. Thirty-two male Sprague-Dawley rats were divided into four groups: sham-operated, I/R, I/R+SMT, and I/R+MEG. Rats were given SMT (10 mg/kg ip) or MEG (10 mg/kg ip) 6 h prior to I/R and at the beginning of reperfusion. All rats except sham-operated underwent 60 min of bilateral renal ischemia followed by 6 h of reperfusion. After reperfusion, kidneys and blood were obtained for evaluation. Superoxide dismutase, glutathione peroxidase, malondialdehide, protein carbonyl content, and nitrite/nitrate level (NO_x) were determined in the renal tissue. Serum creatinine (S_Cr), blood urea nitrogen (BUN), and aspartate aminotransferase (AST) were determined in the blood. Additionally, renal sections were used for histological grade of renal injury. Results. SMT and MEG significantly reduced the I/R-induced increases in S_Cr, BUN, and AST. Both SMT and MEG attenuated the tissue NO_x levels, indicating reduced NO production. In addition, SMT and MEG markedly reduced elevated oxidative stress product, restored decreased antioxidant enzymes, and attenuated histological alterations. Interestingly, MEG exerted a greater renoprotective effect than SMT. Conclusions. These data support the finding that iNOS and peroxynitrite are involved in the renal I/R injury, and suggest that a scavenger of peroxynitrite might be more effective than iNOS inhibitors as a therapeutic intervention.     

Nebivolol Reduces Experimentally Induced Warm Renal Ischemia Reperfusion Injury in Rats

Ischemia/reperfusion injury, which is commonly seen in the field of renal surgery or transplantation, is a major cause of acute renal failure. The objective of the present study was to examine the role of nebivolol in modulating peroxynitrite species-induced inflammation and apoptosis after renal warm ischemia/reperfusion injury in rats. The present study was designed to investigate the effects of nebivolol on the renal warm ischemia/reperfusion injury in rats treated with the nitric oxide synthase inhibitor, N^ω-nitro-L-arginine methyl ester. After right nephrectomy, nebivolol was administered for 15 days. On the 16^th day, ischemia was induced in contra lateral kidney for 45 min, followed by reperfusion for 24 hr. Renal function, inflammation, and apoptosis were estimated at the end of 24 hr reperfusion. Nebivolol improved the renal dysfunction and reduced inflammation and apoptosis after renal ischemia/reperfusion injury. In conclusion, nebivolol shows potent anti-apoptotic and anti-inflammatory properties due to its NO-releasing property. These findings may have major implications in the treatment of human ischemic acute renal failure.     

Posttreatment with Aminoguanidine Attenuates Renal Ischemia/Reperfusion Injury in Rats

Acute renal failure secondary to ischemia/reperfusion (I/R) injury is associated with significant mortality and morbidity. Aminoguanidine (AG), an inducible nitric oxide synthase inhibitor with antioxidant properties, has been reported beneficial in renal I/R injury. The aim of the present study was to investigate the effect of AG on renal I/R injury and compare the effectiveness of different AG treatment modalities. Sprague-Dawley rats were randomly assigned to one of four groups. The control group (n?=?6) received sham operation. The I/R group (n?=?6), AG-I group (n?=?8), and AG-II group (n?=?8) received bilateral renal ischemia for 45 min followed by 24 hours of reperfusion. The AG-I group received AG (50 mg/kg) intraperitoneally four hours and 10 minutes before the induction of ischemia. The AG-II group received AG (50 mg/kg) intraperitoneally four hours and 10 minutes after the initiation of reperfusion. Serum urea and creatinine levels increased significantly in the I/R and AG-I groups compared to the control group. Kidney samples from rats in the I/R and AG-I groups revealed severe tubular damage at histopathological examination. Posttreatment with AG significantly reduced serum urea and creatinine levels and improved histopathological lesions compared with the I/R group. Although pretreatment with AG failed to protect kidneys against I/R injury in this experimental model, posttreatment with AG attenuated renal dysfunction and histopathological changes after I/R injury.     

两种麻醉方法对肝脏缺血再灌注后SOD与MDA影响的比较

目的:比较丙泊酚-瑞芬太尼靶控静脉麻醉与异氟烷吸入麻醉对肝脏部分切除术缺血再灌注损伤后超氧化物歧化酶和丙二醛变化。方法:30例患者随机分为丙泊酚-瑞芬太尼组(PR组)和异氟烷组(ISO组),PR组丙泊酚和瑞芬太尼血浆靶浓度分别为3.5μg/mL和4.2ng/mL,ISO组异氟烷呼气末浓度为1.5%～2.5%。分别于阻断肝门前(T1),阻断开放后即刻(T2)、30min(T3)、60min(T4),术后1d(T5)、术后3d(T6)取静脉血测血清总超氧化物歧化酶(T-SOD)、丙二醛(MDA)浓度。结果:与T1比较,T-SODPR组及ISO组T4、T5、T6显著降低(P<0.05),ISO组T5、T6显著低于PR组(P<0.05);与T1比较,MDAPR组T5、T6,ISO组T4、T5、T6显著升高(P<0.05),ISO组T4、T5显著高于PR组(P<0.05)。结论:与异氟烷麻醉组比较,丙泊酚-瑞芬太尼麻醉组的肝脏缺血再灌注损伤后超氧化物歧化酶和丙二醛变化较小,提示其对肝细胞具有一定保护作用。     

The Effect of Dietary Ginger (Zingiber officinals Rosc) on Renal Ischemia/Reperfusion Injury in Rat Kidneys

Oxidative stress has been considered as one of the possible mechanisms of ischemia/ reperfusion (I/R) injury in the kidney. The aim of this study was to analyze the possible protective effect of dietary ginger (Zingiber officinals Rosc), a free radical scavenger, on renal I/R injury in rats. The protective effect of ginger against the damage inflicted by reactive oxygen species (ROS) during renal I/R was investigated in Wistar albino rats using histopathological and biochemical parameters. Thirty rats were randomly divided into five experimental groups (i.e., control, sham-operated, ginger, I/R, and I/R + ginger groups, n = 6 each). The ginger and I/R + ginger groups were fed on the test diet containing 5% ginger. The rats were subjected to bilateral renal ischemia followed by reperfusion in I/R and I/R + ginger groups. At the end of the reperfusion period, rats were sacrificed, and kidney function tests, serum and tissue oxidants and antioxidants, and renal morphology were evaluated. Serum urea, creatinine, and cystatin C (CYC) levels were significantly elevated in the ischemia group, but these levels remained unchanged in the ginger + I/R group compared to the I/R group. Reduction of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) enzyme activity was significantly improved by the treatment with ginger compared to I/R group. Administration of ginger resulted in significant reduction levels of tissue malondialdehyde (MDA), NO, protein carbonyl contents (PCC) in the ginger + I/R group compared with the I/R group. Ginger supplementation in the diet before I/R injury resulted in higher total antioxidant capacity (TAC) and lower total oxidant status (TOS) levels than I/R group. The ginger supplemented diet prior to I/R process demonstrated marked reduction of the histological features of renal injury. The findings imply that ROS play a causal role in I/R-induced renal injury, and ginger exerts renoprotective effects probably by the radical scavenging and antioxidant activities.     

GM-CSF Promotes Macrophage Alternative Activation after Renal Ischemia/Reperfusion Injury

After kidney ischemia/reperfusion (I/R) injury, monocytes home to the kidney and differentiate into activated macrophages. Whereas proinflammatory macrophages contribute to the initial kidney damage, an alternatively activated phenotype can promote normal renal repair. The microenvironment of the kidney during the repair phase mediates the transition of macrophage activation from a proinflammatory to a reparative phenotype. In this study, we show that macrophages isolated from murine kidneys during the tubular repair phase after I/R exhibit an alternative activation gene profile that differs from the canonical alternative activation induced by IL-4–stimulated STAT6 signaling. This unique activation profile can be reproduced in vitro by stimulation of bone marrow-derived macrophages with conditioned media from serum-starved mouse proximal tubule cells. Secreted tubular factors were found to activate macrophage STAT3 and STAT5 but not STAT6, leading to induction of the unique alternative activation pattern. Using STAT3-deficient bone marrow-derived macrophages and pharmacologic inhibition of STAT5, we found that tubular cell-mediated macrophage alternative activation is regulated by STAT5 activation. Both in vitro and after renal I/R, tubular cells expressed GM-CSF, a known STAT5 activator, and this pathway was required for in vitro alternative activation of macrophages by tubular cells. Furthermore, administration of a neutralizing antibody against GM-CSF after renal I/R attenuated kidney macrophage alternative activation and suppressed tubular proliferation. Taken together, these data show that tubular cells can instruct macrophage activation by secreting GM-CSF, leading to a unique macrophage reparative phenotype that supports tubular proliferation after sterile ischemic injury.     

Heme Oxygenase-1 Overexpression Protects Rat Livers from Ischemia/Reperfusion Injury with Extended Cold Preservation

This study analyzes the effects and mechanisms of heme oxygenase-1 (HO-1)-mediated cytoprotection in rat livers exposed to cold preservation. In the first series, rats were pretreated with cobalt protoporphyrin (CoPP) or zinc protoporphyrin (ZnPP), HO-1 inducer and antagonist, respectively. Livers were stored at 4 degrees C for 24 h, and then perfused ex vivo for 2 h. Livers pretreated with CoPP had significantly higher portal venous blood flow and increased total bile production, as compared with the ZnPP group. This correlated with histologic (Banff) criteria of hepatocyte injury/liver function. In the second series, rat livers were stored at 4 degrees C for 24 h or 40 h, and then transplanted into syngeneic recipients. After 24 h of preservation, 80% of rats bearing CoPP-pretreated liver grafts survived 21 days (vs. 50% in controls). After 40h of cold preservation, liver transplant survival at day 1, 7 and 21 for the CoPP group was: 100%, 71% and 57%, respectively (vs. 50%, 50% and 33% in controls). This correlated with improved hepatic function/histologic (Suzuki) criteria of hepatocyte injury after HO-1 overexpression (immunohistology/Western blots) by infiltrating macrophages. This study documents the potential utility of HO-1-inducing agents in preventing ischemia/reperfusion injury resulting from prolonged storage of liver transplants.