Triptolide inhibits NF-kappaB activation and reduces injury of donor lung induced by ischemia/reperfusion

Aim： To investigate the protective effect of triptolide （TRI） on ischemia/reperfusion- induced injury of transplanted rabbit lungs and to investigate the mechanisms underlying the actions of TRI. Methods： We established the rabbit lung trans- plantation model and studied lung injury induced by ischemia/reperfusion and the inhibitory effect of TRI on NF-KB. The severity of lung injury was determined by a gradual decline in PvO2, the degree of lung edema, the increase in the myeloperoxidase （MPO） activity, and the ultrastructural changes of transplanted lungs. The activation of NF-KB was measured by immunohistochemistry. The increase in intercellular adhesion molecule-1 （ICAM-1）, which is the target gene of NF-KB, was evaluated by ELISA. Results： After reperfusion, there was a gradual decline in the PvO2 level in the control group （group Ⅰ）. The level of PvO2 in the group treated with lipopolysaccharide （group Ⅱ） was significantly decreased, whereas that of the group treated with TRI （group Ⅲ） was markedly improved （P〈0.01）. In group III, the activity of MPO was downregulated, and the pulmonary edema did not become severe and the ultrastructure of the donor lung remained normal. The activity of NF-KB and the expression of ICAM- 1 was significantly increased in the donor lungs. TRI blocked NF-KB activation and ICAM-1 expression. Conclusion： The effects of TRI on reducing injury to donor lungs induced by ischemia/reperfusion may possibly be mediated by inhibiting the activity of NF-KB and the expression of the NF-KB target gene ICAM-1. Thus, TRI could be used in lung transplantations for improving the function of donor lungs.     

S-15176 reduces the hepatic injury in rats subjected to experimental ischemia and reperfusion

The protective effect of N-[(3, 5-di-tertiobutyl-4-hydroxy-1-thiophenyl)]-3-propyl-N'-(2,3, 4-trimethoxybenzyl)piperazine (S-15176) on liver injury induced by warm ischemia-reperfusion was investigated using a rat model. Animals were subjected to 2 h of ischemia followed by different reperfusion times. Hepatocyte integrity was assessed by measuring plasma alanine and aspartate aminotransferase activities, and by determining reduced and oxidized glutathione in plasma and bile. Hepatocyte function was quantitated by determining bile flow and liver ATP content. Ischemia-reperfusion resulted in severe hepatic injury involving a huge increase in alanine and aspartate aminotransferase activities, a drop in ATP content, and a decrease in bile flow. Plasma and bile reduced (GSH) and oxidized (GSSG) glutathione concentrations were inversely related: plasma levels increased when biliary levels decreased. This was associated with a decrease in animal survival (-34%). S-15176 pretreatment (1.25, 2.5, 5 or 10 mg kg(-1) day(-1)) improved the survival rate and limited tissue damages in a dose-dependent manner. The pretreatment also reduced the aminotransferase leakage from hepatocytes and the increase in plasma glutathione levels. In addition, normalization of the plasma GSSG/GSH ratio, a good index of an oxidative stress, was observed in groups treated with the higher dosage, suggesting that the antioxidant properties demonstrated for the compound in vitro (IC(50)=0.3 microM towards lipid peroxidation) could play a role in its protective effect. S-15176 pretreatment also protected the organ from the drop in ATP levels. At the higher dose, ATP content was maintained at a level almost 86% of the sham-operated group after 60 min of reperfusion. This was associated with a restoration of the biliary flow. These data suggest that S-15176 may be a useful drug in liver surgery to prevent ischemia-reperfusion injury.     

The effects of tramadol on hepatic ischemia/reperfusion injury in rats

Objectives:Tramadol is a centrally acting synthetic analgesic. It has a cardioprotective effect against myocardial ischemia-reperfusion (I/R) injury in isolated rat heart. We hypothesized that tramadol may exert a similar protective effect on hepatic I/R injury. Hence, the current investigation was designed to study the possible protective effects of tramadol on experimentally-induced hepatic I/R injury in rats.Results:Tramadol attenuated hepatic injury induced by I/R as evidenced by the reduction of transaminases, structural changes, and apoptotic cell death. It decreased the level of inflammatory markers such as tumor necrosis factor-alpha (TNF-α), TNF-α/interleukin-10 (IL-10) ratio, and nuclear factor-κB gene expression. It also increased the anti-inflammatory cytokine, IL-10 levels in hepatic tissues. Furthermore, it reduced oxidative stress parameters except manganese superoxide dismutase activity.Conclusion:The results suggest that tramadol has hepatoprotective effects against hepatic I/R injury via anti-inflammatory, antiapoptotic, and antioxidant effects.KEY WORDS: Angioedema, anti-histamines, chronic urticaria, histaglobulin, urticaria activity score     

Protective effect of lisinopril on hepatic ischemia/reperfusion injury in rats

Objective:

Ischemia/reperfusion (I/R) injury plays a key role in the pathogenesis of hepatic failure in several clinical settings such as liver resection or transplantation. Lisinopril, a widely prescribed drug for various cardiovascular conditions, has been reported to have diverse pharmacological properties. The aim of this study, therefore, was to evaluate a potential protective effect of lisinopril on hepatic I/R injury in rats.

Materials and Methods:

In anesthetized rats, partial hepatic ischemia was applied for one hour followed by two hours reperfusion. Biochemical analysis of serum and hepatic tissue was done. Hepatic tissue was also subjected to electron microscopy.

Results:

Pre-ischemic treatment with lisinopril (10 mg/kg) exerted protection against I/R-induced hepatocellular injury as evident by significant decrease in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin levels, along with hepatic lipid peroxidation, expressed as malondialdehyde content, with a concurrent increase in hepatic nitric oxide content as compared to I/R group. The electron microscopic examination indicated that lisinopril can effectively protect against hepatic I/R injury.

Conclusion:

Lisinopril provides a protection against hepatic I/R injury in rats. The protective effect is associated with reduction of oxidative stress-induced lipid peroxidation level and enhancement of nitric oxide availability.KEY WORDS: Ischemia/reperfusion, lisinopril, liver     

Magnolol reduces myocardial ischemia/reperfusion injury via neutrophil inhibition in rats.

The accumulation of oxygen-free radicals and activation of neutrophils are strongly implicated as important pathophysiological mechanisms mediating myocardial ischemia/reperfusion injury. It has been proven that various antioxidants have cardioprotective effects. Magnolol, an active component extracted from the Chinese medicinal herb Magnolia officinalis, possesses potent antioxidant and free radical scavenging activities. In this study, the cardioprotective activity of magnolol was evaluated in an open-chest anesthetized rat model of myocardial ischemia/reperfusion injury. The results demonstrated that pretreatment with magnolol (0.2 and 0.5 microg/kg, i.v. bolus) at 10 min before 45 min of left coronary artery occlusion, significantly suppressed the incidence of ventricular fibrillation and mortality when compared with the control group. Magnolol (0.2 and 0.5 microg/kg) also significantly reduced the total duration of ventricular tachycardia and ventricular fibrillation. After 1 h of reperfusion, pretreatment with magnolol (0.2 and 0.5 microg/kg) caused a significant reduction in infarct size. In addition, magnolol (0.2 microg/kg) significantly reduced superoxide anion production and myeloperoxidase activity, an index of neutrophil infiltration in the ischemic myocardium. In addition, pretreatment with magnolol (0.2 and 0.5 microg/kg) suppressed ventricular arrhythmias elicited by reperfusion following 5 min of ischemia. In vitro studies of magnolol (5, 20 and 50 microM) significantly suppressed N-formylmethionyl-leucyl-phenylalanine (fMLP; 25 nM)-activated human neutrophil migration in a concentration-dependent manner. It is concluded that magnolol suppresses ischemia- and reperfusion-induced ventricular arrhythmias and reduces the size of the infarct resulting from ischemia/reperfusion injury. This pronounced cardioprotective activity of magnolol may be mediated by its antioxidant activity and by its capacity for neutrophil inhibition in myocardial ischemia/reperfusion.     

Sodium nitroprusside regulates mRNA expressions of LTC4 synthesis enzymes in hepatic ischemia/reperfusion injury rats via NF-kappaB signaling pathway

Leukotriene (LT) C4 (LTC4) synthesis enzymes including LTC4 synthase (LTC4S), microsomal glutathione S-transferase (MGST) 2 and MGST3 can all conjugate LTA4 and reduced glutathione (GSH) to form LTC4, which is related to hepatic ischemia/reperfusion (I/R) injury. The relationship between nitric oxide (NO) and cysteinyl LTs has been shown in previous studies. However, the mechanisms of NO action on gene expression of LTC4 synthesis enzymes are still largely unclear during hepatic I/R. Adult male Sprague-Dawley rats were divided into 5 groups: a sham group (control), an I/R group, and sodium nitroprusside (SNP, 2.5, 5 and 10 microg/kg/min)+I/R groups. Livers were subjected to 60 min of partial hepatic ischemia followed by 5 h of reperfusion, saline or SNP (2.5, 5 and 10 microg/kg/min) administered intravenously. The mRNA levels of LTC4 synthesis enzymes, inducible NO synthase (iNOS) and endothelial No synthase (eNOS) in rat liver tissue were examined by RT-PCR; the protein expressions of NF-kappaB p65, p50 and IkappaBalpha in liver cell lysates and nuclear extracts were detected by Western blot analysis, and serum NO2. levels were also evaluated. Serum NO2. levels, the protein expressions of NF-kappaB p65 and p50 in the nucleus extract, and hepatic mRNA expressions of LTC4S and iNOS were decreased while hepatic mRNA of eNOS was increased in the SNP (5 and 10 microg/kg/min)+I/R groups when compared with those in the I/R group. SNP (2.5 microg/kg/min) promoted the mRNA expressions of both MGST2 and MGST3, whereas SNP (10 microg/kg/min) increased MGST2 mRNA but decreased MGST3 mRNA compared to those in I/R group. Compared with control, the mRNA expression of MGST2 and MGST3 were elevated in SNP (2.5 microg/kg/min)+I/R group, MGST3 mRNA was significantly declined in the SNP (5 and 10 microg/kg/min)+I/R groups. Immunohistochemistry staining revealed that I/R liver exhibited strong cytoplasmic and nuclear staining for NF-kappaB p65, but the livers of the SNP (2.5 microg/kg/min)+I/R group presented slight cytoplasmic and nuclear staining. But IkappaBalpha protein in all groups remains unchanged. It was concluded that SNP downregulated LTC4S mRNA expression by inhibiting NF-kappaB activation independent of IkappaBalpha, but appeared to have a dual influence on the mRNA expressions of MGST2 and MGST3 by other signaling pathways during hepatic I/R injury.     

Rosmarinic acid attenuates hepatic ischemia and reperfusion injury in rats

Rosmarinic acid (RosmA) demonstrates antioxidant and anti-inflammatory properties. We investigated the effect of RosmA on liver ischemia/reperfusion injury. Rats were submitted to 60 min of ischemia plus saline or RosmA treatment (150 mg/kg BW intraperitoneally) followed by 6 h of reperfusion. Hepatocellular injury was evaluated according to aminotransferase activity and histological damage. Hepatic neutrophil accumulation was also evaluated. Oxidative/nitrosative stress was estimated by measuring the reduced glutathione, lipid hydroperoxide and nitrotyrosine levels. Endothelial and inducible nitric oxide synthase (eNOS/iNOS) and nitric oxide (NO) were assessed with immunoblotting and chemiluminescence assays. Hepatic tumor necrosis factor-alpha (TNF-α) and interleukin-1beta mRNA were assessed using real-time PCR, and nuclear factor-kappaB (NF-κB) activation was estimated by immunostaining. RosmA treatment reduced hepatocellular damage, neutrophil infiltration and all oxidative/nitrosative stress parameters. RosmA decreased the liver content of eNOS/iNOS and NO, attenuated NF-κB activation, and down-regulated TNF-α and interleukin-1beta gene expression. These data indicate that RosmA exerts anti-inflammatory and antioxidant effects in the ischemic liver, thereby protecting hepatocytes against ischemia/reperfusion injury. The mechanisms underlying these effects may be related to the inhibitory potential of RosmA on the NF-κB signaling pathway and the reduction of iNOS and eNOS expressions and NO levels, in addition to its natural antioxidant capability.     

肝缺血再灌注损伤大鼠P-选择素的表达

目的 通过测定肝缺血-再灌注损伤（HIRI）模型大鼠中P-选择素在肝脏组织的表达,探讨HIRI的发病机制.方法 将32只健康雌性SD大鼠随机分为四组（每组8只）：假手术组（SO组）、缺血30 min组（Ⅰ组）、缺血30 min再灌注30 min组（IR 30 min组）、缺血30 min再灌注1 h组（IR 1 h组）.采用Pringle 法制作HIRI模型.采用SP试剂盒测定肝组织中P-选择素含量.结果 缺血30 min后,肝组织中P-选择素的表达较SO组无明显差异;再灌注1 h后,P-选择素在肝组织血管内皮、肝细胞内广泛表达,较SO组差异显著.结论 在大鼠肝缺血-再灌注过程中,肝组织中P-选择素的表达逐渐升高.     

雌激素预处理增强肝缺血再灌注损伤大鼠雌激素受体表达

目的探讨雌激素预处理对肝缺血再灌注(I/R)损伤大鼠雌激素受体(ERα)表达的影响。方法采用Pringle法阻断大鼠第一肝门制作95%肝I/R模型。肝缺血前1 h大鼠ip给予雌二醇4 mg·kg-1(雌二醇+I/R组)。分别取肝缺血前(0)、再灌注1,3,6和24 h共5个时间点的血液标本,检测血清谷丙转氨酶(ALT)水平;ELISA法测定血清肿瘤坏死因子-α(TNF-α)水平;HE染色观察肝组织形态学变化,免疫组化方法检测肝核因子κB(NF-κB)和ERα的表达。结果与假手术组相比,I/R模型组和雌二醇+I/R组血清ALT和TNF-α水平、肝组织NF-κB和ERα表达明显升高(P<0.01);与假手术组相比,再灌注6 h,I/R和雌二醇+I/R组血清ALT水平分别升高了11.7倍和8.1倍(P<0.01),TNF-α水平分别升高5.2倍和3.2倍(P<0.01),但雌二醇+I/R组升高幅度明显低于I/R组(P<0.05);与假手术组相比,再灌注6 h I/R组和雌二醇+I/R组肝组织NF-κB表达分别升高了8.6倍和4.8倍,但雌二醇+I/R组升高幅度明显低于I/R组(P<0.01);ERα表达分别升高了4.2倍和7.4倍,雌二醇+I/R组升高幅度明显高于I/R组(P<0.01);雌二醇+I/R组肝组织损伤明显轻于I/R组。结论雌激素预处理可减轻I/R导致的肝组织损伤程度,此作用与增强ERα表达有关。     

白藜芦醇对大鼠脑缺血/再灌注损伤后星形胶质细胞活化的影响

目的研究白藜芦醇对大鼠脑缺血/再灌注损伤后星形胶质细胞活化的影响。方法 45只SD♂大鼠随机分成假手术组(Sham)、对照组(Con)和白藜芦醇组(30 mg·kg-1,Res),每组15只。于缺血/再灌注后3 h使用白藜芦醇或溶剂治疗,连用7 d。脑缺血24 h时,TTC法检测脑梗死体积,HE染色检测病理变化,Longa评分行神经功能评分,免疫组织化学检测缺血半暗带皮质半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)的表达。脑缺血14 d时,免疫组织化学及免疫荧光法检测胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)和神经元NeuN蛋白表达。结果白藜芦醇治疗较对照组能明显改善神经功能、减小梗死体积、减少神经元脱失及凋亡,抑制星形胶质细胞的活化与增殖(P<0.01)。结论白藜芦醇治疗可抑制星形胶质细胞的异常活化,保护缺血半暗带神经元,改善神经功能。     

葛根素预处理在大鼠肝脏缺血再灌注损伤中的抗氧化作用

目的观察葛根素预处理对大鼠肝脏缺血再灌注损伤的防护作用。方法雄性SD大鼠,建立肝脏缺血再灌注模型（HIR）。随机分为假手术组、HIR组和HIR-葛根素预处理组。黄嘌呤氧化酶法、硫代巴比妥酸比色法分别测定肝组织中丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性的变化,同时分析NO含量的改变。结果肝脏缺血再灌注损伤后,与假手术组比较,肝组织中MDA活性及NO含量均显著增加,而SOD活性显著降低;经40mg/kg剂量的葛根素预处理7d后,与模型组相比,肝组织中MDA活性及NO含量显著降低,而SOD活性增高。结论葛根素预处理对大鼠缺血再灌注肝脏损伤有一定的保护作用。     

Magnesium lithospermate B reduces myocardial ischemia/reperfusion injury in rats via regulating the inflammation response

Abstract

Context: Magnesium lithospermate B (MLB), an active polyphenol acid of Danshen [Radix Salviae miltiorrhizae (Labiatae)], showed renoprotective, neuroprotective and myocardial salvage effects. Previous studies demonstrated that MLB could effectively suppress the production of cytokines and their associated signaling pathways in activated human T cells.

Objective: The purpose of this study was to examine the beneficial effects of MLB on myocardial ischemia/reperfusion (MI/R) injury and to explore its potential mechanisms related to anti-inflammation.

Materials and methods: Sprague–Dawley rats were grouped as sham group, model group and MLB-treated (15, 30 and 60?mg/kg) groups. Animals were subjected to MI/R injury by the occlusion of left anterior descending artery for 30?min followed by reperfusion for 3?h. At the end of reperfusion, blood samples were collected to determine the serum levels of cardiac troponin (cTnI), creatine kinase-MB (CK-MB), tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β) and interleukin 6 (IL-6). Hearts were harvested to assess infarct size, histopathological changes and the activity of myeloperoxidase (MPO). The expression of phosphor-IkB-α and phosphor-nuclear factor kappa B (NF-κB) were assayed by western blot.

Results: MLB administration significantly (p?<?0.05) reduced: (1) ST-segment elevation (0.23?mv), (2) the infarct size (22.5%), (3) histological scores of myocardial injury (1.67 score), (4) myocardial injury marker enzymes: cTnI (5.64?ng/ml) and CK-MB (49.57?ng/ml) levels, (5) pro-inflammatory cytokines: TNF-α (97.36?pg/ml), IL-1β (93.35?pg/ml) and IL-6 (96.84?pg/ml) levels, (6) MPO activity (1.82?U/mg), (7) phosphor-NF-κB (0.87) and phosphor-IkB-α (0.96) expression.

Discussion and conclusion: Our study provided evidence that MLB ameliorated the inflammatory process associated with MI/R injury via NF-κB inactivation.     

雌激素与雌激素受体在大鼠肝脏缺血再灌注损伤中的作用

目的 观察雌激素与雌激素受体在大鼠肝脏缺血再灌注损伤中的作用.方法 用Pringle's大鼠全肝缺血再灌注损伤模型,选取健康清洁级雄性SD大鼠120只,随机分成假手术组、肝缺血再灌注组和雌激素干预组(预处理+肝缺血再灌注组)3组,每组各40只;检测血清谷丙转氨酶(ALT)水平,HE染色观察肝脏组织形态学变化,ELISA法测定血清肿瘤坏死因子-a(TNF-a)水平,免疫组化方法检测肝脏组织核转录因子(NF-KB)和雌激素受体(ER)的表达情况.结果 假手术组,血清ALT,TNF-a水平升高不明显,ER,NF-KB表达无明显变化,肝脏组织形态学改变不明显;缺血再灌组、雌激素干预组的ALT,TNF-a水平与ER,NF-KB表达显著升高;但雌激素干预组ER表达明显高于缺血再灌组,缺血再灌组的NF-KB表达明显高于雌激素干预组,缺血再灌组的肝脏组织损伤程度显著高于雌激素干预组.结论 雌激素能刺激雌激素受体表达,进而降低TNF-a水平、抑制NF-KB表达,来减轻肝脏缺血再灌注损伤.     

血必净对大鼠肝缺血-再灌注后急性肺损伤的保护作用

目的观察肝脏缺血-再灌注后急性肺损伤的发病机制及血必净对其的干预作用。方法将健康雄性Wistar大鼠90只随机分3组:假手术组(SOG组)30只,缺血再灌注组(I/R组)30只,血必净组(XBJ组)组30只。XBJ组术前3d经尾静脉注射血必净注射液5ml·kg-1·d-1。于再灌注6h、12h、24h各组分别随机选取10只大鼠进行标本检测:观察大鼠肺脏组织病理切片;取新鲜肺组织测定湿/干重比(W/D)、肺组织髓过氧化物酶(MPO)含量,取动脉血检测血气分析(PaO2)。结果XBJ组较I/R组在相同时相点的肺脏病理改变较轻,MPO含量显著降低(P<0.01);W/D显著降低(P<0.01);PaO2升高(P<0.05)。结论血必净注射液对肝脏缺血-再灌注后急性肺损伤具有保护作用,该作用与抑制中性粒细胞在肺内集聚、减少氧自由基的产生有关。     

The potential curative effect of rebamipide in hepatic ischemia/reperfusion injury

Rebamipide (Reba), a gastroprotective drug, has signified its hepatoprotective activity; however, its possible post-therapeutic intervention in hepatic ischemia/reperfusion (I/R) remains elusive. Consequently, the intent of this study was to test Reba modulatory effect on nuclear factor (NF)-κB signaling in hepatic I/R model. Rats were randomized into sham, I/R, Reba 60, and Reba100 (60 and 100 mg/kg, respectively) groups. Ischemia was induced for 30 min followed by 3-day reperfusion to set up a model of partial (70%) warm hepatic ischemia. Post-treatment with Reba reduced the serum level of alanine transaminase, improved histopathological alterations of the liver, and elevated hepatic adenosine triphosphate. It also lowered hepatic lipid peroxides and increased both total antioxidant capacity and nitric oxide. Besides, Reba decreased tumor necrosis factor-α, interferon-γ, intercellular adhesion molecule-1, myeloperoxidase, prostaglandin E₂, cyclooxygenase-2 expression/content, and caspase-3 activity. Reba also upregulated the gene expression/content of sirtuin 1 (SIRT-1), while it downregulated that of high mobility group box (HMGB)1 and reduced the expression/content of NF-κB p65/pS536-NF-κB and the content of pT180/Y182-p38MAPK. Reba provided tenable hepato-therapeutic mechanisms to mitigate events concomitant with hepatic I/R via inhibition of NF-κB p65 and modulation of its influential signals (SIRT-1, HMGB1, p38MAPK) associated with its antiinflammatory, antioxidant, and antiapoptotic impacts.

     

维生素E在大鼠肝脏缺血再灌注损伤中的作用

目的探讨维生素E在肝组织缺血再灌注(I/R)损伤的保护机制及对缺血预处理(IP)的影响。方法采用大鼠原位半肝缺血再灌注和缺血预处理模型,缺血前通过灌胃给予维生素E(250mg/kg),分析血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、乳酸脱氢酶(LDH)、全血还原型谷胱甘肽(GSH)、肝组织脂质过氧化物(LPO)、超氧化物歧化酶(SOD)含量及肝组织病理改变等各项指标。结果I/R导致明显的肝损伤,IP减轻肝I/R损伤,维生素E能减轻肝组织缺血再灌注损伤,但可以部分抵消IP的保护作用。结论维生素E能减轻肝组织缺血再灌注损伤,其作用是通过减少氧自由基产生而实现的。IP对鼠肝I/R有明显的保护作用,IP期间产生的一定量的自由基,对随后的I/R的保护作用具有重要意义。维生素E导致氧自由基减少是肝IP保护作用的不利因素。     

Protective effects of ginseng total saponins against hepatic ischemia/reperfusion injury in experimental obstructive jaundice rats

Abstract

Context: Ginseng, the root of Panax ginseng C.A. Meyer (Araliaceae), is one of the most extensively used herbs for stroke and chronic debilitating conditions in East Asian countries. Ginsenosides (GS) are the main bioactive compounds for ginseng's efficacy, but the mechanisms have not been fully clarified.

Objective: To investigate hepatoprotective effects of GS against ischemia/reperfusion (IR) injury in the experimental obstructive jaundice rats.

Materials and methods: GS was fed to cholestatic rats with IR injury daily for 6?d at a dose of 1.10?g/kg. Levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), superoxide dismutase (SOD) and malondialdehyde (MDA) were determined by colorimetric method. Apoptosis was measured quantitatively by the terminal transferase UTP nick end-labeling method. Protein expression of Bax and Bcl-2 was detected by immunohistochemistry.

Results and discussion: After intervention of GS to cholestatic rats with IR injury, the levels of activating blood flow were significantly improved, and the levels of serum ALT were decreased 1.7-times, AST decreased 1.3-times, but SOD activities were increased 1.1-times compared with those of the model rats. It could also reverse histopathological changes and inhibit IR-induced apoptosis of hepatic tissues via decrease of Bax/Bcl-2 ratio (from 2.87?±?0.57 to 1.65?±?0.29). Oral administration of GS in a dosage of 26.4?g/kg did not lead to toxic effects in rats.

Conclusion: GS attenuated the IR injury in the presence of cholestasis and could be considered for the clinical treatment of cholestasis.     

The role of cytokines in pharmacological modulation of hepatic ischemia/reperfusion injury

Hepatic ischemia/reperfusion injury is a complication of liver resection surgery, transplantation and hypovolemic shock, leading to local and remote cellular damage and organ dysfunction. This injury is largely a result of an acute inflammatory response characterized by the induction of a cascade of proinflammatory mediators that culminates in the recruitment of leukocytes to the post-ischemic tissue leading to parenchymal cell injury. Endogenous regulatory mechanisms exist to attempt to control this inflammatory response. These include anti-inflammatory cytokines that function to suppress proinflammatory mediator expression. In this review, we address the current knowledge of the pro- and anti-inflammatory cytokine components of the acute liver inflammatory response to ischemia/reperfusion as well as how these cytokines can be manipulated to reduce post-ischemic liver injury.     

Montelukast protects against renal ischemia/reperfusion injury in rats.

BACKGROUND: Oxygen free radicals are important components involved in the pathophysiological processes observed during ischemia/reperfusion (I/R). OBJECTIVE: This study was designed to assess the possible protective effect of montelukast, a selective antagonist of cysteinyl leukotriene receptor 1 (CysLT1), on renal I/R injury. METHODS: Wistar albino rats were unilaterally nephrectomized and subjected to 45 min of renal pedicle occlusion followed by 6 h of reperfusion. Montelukast (10 mgkg(-1), i.p.) or saline was administered at 15 min prior to ischemia and immediately before the reperfusion period. At the end of the reperfusion period, following decapitation, kidney samples were taken for histological examination or for determination of renal malondialdehyde (MDA), an end product of lipid peroxidation; glutathione (GSH), a key antioxidant; and myeloperoxidase (MPO) activity, an index of tissue neutrophil infiltration. Formation of reactive oxygen species in renal tissue samples was monitored by using chemiluminescence (CL) technique with luminol and lucigenin probes. Creatinine, blood urea nitrogen and lactate dehydrogenase (LDH) activity were measured in the serum samples, while leukotriene B4, TNF-alpha, IL-beta, IL-6 and total antioxidant capacity (AOC) were assayed in plasma samples. RESULTS: Ischemia/reperfusion caused a significant decrease in renal GSH and plasma AOC, which was accompanied with significant increases in MDA level, MPO activity, and CL levels of the renal tissue concomitant with increased levels of the pro-inflammatory mediators, LDH activity, creatinine and BUN. On the other hand, montelukast treatment reversed all these biochemical indices as well as histopathological alterations induced by I/R. CONCLUSIONS: CysLT1 receptor antagonist montelukast reversed I/R-induced oxidant responses, improved microscopic damage and renal function. It seems likely that montelukast protects kidney tissue by inhibiting neutrophil infiltration, balancing oxidant-antioxidant status, and regulating the generation of inflammatory mediators.     

rhEPO对大鼠肝脏缺血再灌注损伤的保护作用

目的:探讨rhEPO对大鼠肝脏缺血再灌注损伤中的保护作用及其处理时间。方法:健康Wistar大鼠36只,随机分为对照组A、缺血前30 min预处理组B和缺血后5 min后处理组C 3组,每组12只。A组只给予夹闭肝蒂,B、C组均于皮下注射rhEPO 1 000 U/kg,三组均夹闭肝蒂45 min后恢复再灌注2 h,取血清及肝组织行AST、ALT、TNF-α、IL-1β检测及HE染色、NF-κβ的活化程度及计算肝组织凋亡指数(AI)。结果:与A组比较,B、C组肝细胞索排列较好,细胞坏死程度不明显。AST、ALT和TNF-α、IL-1β及NF-κB活化程度、AI在A组和B、C组之间均有显著差异(P<0.05),B和C组之间(除IL-1β外)也具有统计学意义(P<0.05)。结论:rhEPO对缺血再灌注损伤的肝脏具有保护作用且预处理较后处理效果好。