小剂量氯胺酮预处理对大鼠肠缺血再灌注损伤的影响

目的 探讨小剂量氯胺酮预处理对大鼠肠缺血再灌注损伤的影响.方法 清洁级健康雄性SD大鼠48只,体重230～270 g,随机分为6组(n=8):假手术组(S组)、氯胺酮+假手术组(KS组)、肠缺血再灌注组(I/R组)、氯胺酮预处理组(K组)、锌原卟啉Ⅸ+氯胺酮预处理组(KZ组)和锌原卟啉Ⅸ组(Z组).采用夹闭肠系膜上动脉根部1 h后再灌注的方法 制备肠缺血再灌注模型.于麻醉前30 min时,S组腹腔注射生理盐水2 ml,K组和KS组均腹腔注射氯胺酮10 mg/kg,KZ组依次腹腔注射氯胺酮10 ms/kg和锌原卟啉Ⅸ5 mg/kg,Z组腹腔注射锌原卟啉Ⅸ5 mg/kg.S组、KS组仅分离肠系膜上动脉,不结扎.于再灌注6 h时处死大鼠,取肠组织测定丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性、血红素加氧酶-1(HO-1)及诱导型一氧化氮合酶(iNOS)的表达,光镜下观察肠组织病理学结果 并采用Chiu评分评价损伤程度.结果 与S组比较,I/R组、KZ组和Z组肠组织MDA含量升高,SOD活性降低,K组MDA含量升高(P<0.05或0.01),SOD活性差异无统计学意义(P>0.05),I/R组、K组、KZ组和Z组肠组织HO-1和iNOS表达上调(P<0.05或0.01),肠组织病理学损伤加重;与I/R组比较,K组肠组织MDA含量降低,SOD活性升高,肠组织HO-1表达上调,iNOS表达下调(P<0.05),肠组织病理学损伤减轻,KZ组和Z组以上指标差异无统计学意义(P>0.05).结论 小剂量氯胺酮预处理可减轻大鼠肠缺血再灌注损伤,可能与氯胺酮上调肠组织HO-1表达,下调iNOS表达有关.     

Pioglitazone Attenuates Ischemia/Reperfusion–Induced Liver Injury in Rats

Introduction

Hepatic ischemia/reperfusion (I/R) injury leads to free radical generation and acute inflammatory responses that cause liver damage, an important problem for liver transplantation. Pioglitazone is known to protect I/R injury in various tissues; however, the mechanism of cytoprotection is not well understood. This study investigated the effects of pioglitazone administration in a warm hepatic I/R model on tumor necrosis factor (TNF)-α level, tissue injury, and antioxidant enzyme activity.

Materials and Methods

Eighty wistar strain rats were divided into 4 groups (n = 20): Group 1 sham hosts; Group 2 hepatic I/R; Group 3 hepatic I/R + pioglitazone (10 mg/kg); and Group 4 hepatic I/R + vehicle. Rat livers were subjected to 30 minutes of ischemia followed by 6 hours of reperfusion. After reperfusion rats were humanely killed to obtain liver tissue to study glutathione peroxidase (GPx), superoxide dysmutase (SOD), malondialdehyde (MDA) levels and for histopathologic assessment. TNF-α, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were measured in serum.

Results

Pioglitazone pretreatment significantly reduced liver enzyme content (ALT, 176.80 ± 13.75 vs 235.28 ± 31.92 and AST, 748.20 ± 79.29 vs 944.85 ± 101.87) and TNF-α level (9:8.60 ± 8.67 vs 138.28 ± 9.99) after I/R compared with the control group. MDA level (3.02 ± 0.37 vs 4.36 ± 0.38) and hepatocytic degeneration were reduced in the pioglitazone-treated group. GPx (2.40 ± 0.25 vs 1.36 ± 0.31) and SOD activity (2.22 ± 0.30 vs 1.40 ± 0.35) were significantly higher in the pioglitazone-treated group compared with the control group.

Conclusion

The present study showed that pioglitazone administration improved hepatic I/R injury that was associated with enhanced antioxidant enzyme activities and suppression of TNF-α, ALT, and AST levels. Because peroxisome proliferator-activated receptor-γ agonists are widely used to treat diabetic patients, it may be relatively easy to expand their clinical indication. However, further investigations will be required to delineate protective mechanisms by which pioglitazone attenuates hepatic tissue injury after I/R.     

血红素加氧酶-1对乳鼠心肌细胞缺氧复氧损伤的影响

目的 探讨血红素加氧酶-1(HO-1)对乳鼠心肌细胞缺氧复氧损伤的影响.方法 新生SD大鼠8只,日龄1～3 d,原代培养心肌细胞,随机分为4组:正常对照组(C组)常规培养8 h;缺氧复氧组(HR组)采用缺氧2 h,复氧6 h的方法制备心肌细胞缺氧复氧模型;血晶素组(Hemin组)缺氧前24 h及缺氧即刻,培养基中加入Hemin,终浓度为20 μmol/L;血晶素+锌原卟啉组(Hemin+ZnPP组)缺氧前24 h及缺氧即刻培养基中同时加入Hemin及ZnPP,终浓度均为20 μmol/L.各组细胞均接种于35 mm培养皿(2 ml/皿)或50 ml培养瓶(3 ml/瓶),每组45皿和3瓶.于复氧结束后采用蛋白印迹法测定心肌细胞HO-1表达,台盼蓝染色法测定心肌细胞存活率,应用全自动生化分析仪测定细胞培养液乳酸脱氧酶(LDH)活性,超声破碎细胞离心后取上清,采用硫代巴比妥酸法测定细胞MDA水平,黄嘌呤氧化酶法测定细胞SOD活性.结果 与C组比较,其余3组培养液LDH活性、心肌细胞MDA水平及HO-1表达升高,心肌细胞存活率及SOD活性降低(P＜0.05).与HR组比较,Hemin组培养液LDH活性、心肌细胞MDA水平降低,HO-1表达、心肌细胞存活率及SOD活性升高(P＜0.05),Hemin+ZnPP组上述指标差异无统计学意义(P＞0.05).HR组和Hemin+ZnPP组细胞缺氧复氧损伤明显,Hemin组细胞缺氧复氧损伤减轻.结论 HO-1可减轻乳鼠心肌细胞缺氧复氧损伤.     

上调肝脏HO-1抑制肥大细胞脱颗粒减轻大鼠肝脏缺血再灌注损伤

目的 探索HO-1对肝脏缺血再灌注损伤中肥大细胞脱颗粒的影响。方法 将20只SD大鼠随机分成4组：假手术组（Sham组）,缺血再灌注损伤组（I/RI组）,HO-1诱导剂钴原卟啉组(CoPP组,术前24h给予CoPP,5 mg/kg)及HO-1抑制剂锌原卟啉组(ZnPP组,术前24h给予ZnPP,20 mg/kg)。建立大鼠缺血再灌注损伤模型,各组于再灌注后2h收集标本。RT-PCR检测肝脏组织HO-1 mRNA表达,Western blot检测肝脏组织HO-1蛋白表达;测定血清中ALT、AST水平;肝脏组织甲苯胺蓝染色检测肥大细胞脱颗粒数量,HE染色评价肝脏组织损伤情况。结果 与Sham组相比,I/RI组、CoPP组、ZnPP组大鼠组织HO-1 RNA和蛋白表达增加,血清ALT、AST水平升高,肥大细胞脱颗粒数量增多,肝脏细胞损伤加重。CoPP组与I/RI组相比,HO-1 mRNA和蛋白表达增加,血清ALT、AST水平减低,肥大细胞脱颗粒数量减少,肝细胞损伤减轻。ZnPP组与I/RI组相比,HO-1 mRNA和蛋白表达减少,血清ALT、AST水平升高,肥大细胞脱颗粒数量增多、肝细胞损伤严重。组间比较差异具有统计学意义(P＜0.05)。结论 HO-1过表达能减轻肝脏I/RI,其机制可能与抑制肝脏组织中肥大细胞脱颗粒有关。     

Pharmacological preconditioning with simvastatin protects liver from ischemia-reperfusion injury by heme oxygenase-1 induction

BACKGROUND: The protective role of heme oxygenase-1 (HO-1) against liver ischemia-reperfusion (I/R) injury in models of hypoxic and remote preconditioning has been proved. The feasible candidates who induce HO-1 and thorough which exert the protective effects are under investigation. The aim was to study the role of HO-1 in pharmacological preconditioning by simvastatin in a rat model. METHODS: Pharmacological preconditioning by intraperitoneal injection of simvastatin (5 mg/kg) was tested on a partial liver I/R model on rats. The expression of HO-1 protein and enzyme activities in livers, serum alanine transaminase (ALT) levels, and TUNEL staining of liver after I/R injury were measured in rats with and without simvastatin preconditioning. RESULTS: HO-1 was induced and persistently overexpressed in the hepatocytes 24 hr after simvastatin treatment. Simvastatin preconditioning diminished the elevation of serum ALT levels 4 hr after I/R injury (69.6+/-26.3 U/L) (P<0.05 vs. other groups) when compared with control (403.8+/-261.9 U/L) and zinc protoporphyrin (ZnPP)-pretreated (717.5+/-205.6 U/L) groups. Simvastatin preconditioning diminished the apoptosis after I/R injury as well (apoptosis index: 26.4+/-8 for Simvastatin, 78+/-7 for control, and 85.3+/-2 for ZnPP group; P<0.05). The addition of ZnPP negated the protective effects of simvastatin as evidenced in the ALT level (406.2+/-243.0 U/L) and apoptosis index (75.6+/-6). The heme oxygenase activity in treated rats correlated with these results. CONCLUSIONS: The induction of HO-1 by simvastatin preconditioning played a protective role against hepatic I/R injury.     

内源性一氧化碳在大鼠肢体缺血再灌注致远隔多脏器氧化性损伤中的作用

目的　探讨内源性一氧化碳 (CO)在大鼠肢体缺血再灌注 (I/ R)致远隔多器官氧化性损伤中的作用机制。方法　将 6 4只大鼠随机分为 4组 :假手术 (Sham )组 ;Sham 特异性血红素氧化酶阻断剂—锌原卟啉 (Zn PP)组 ;肢体缺血 2小时和再灌注 4小时 (I/ R)组 ;I/ R Zn PP组。测定各组心、肺、肝和肾组织匀浆中丙二醛 (MDA )含量、超氧化物歧化酶 (SOD)活性及血液内碳氧血红蛋白 (COHb)的变化 ,观察动物 2 4小时存活率。结果　与 Sham组相比 ,I/ R组各脏器 MDA含量及血液内 COHb水平均显著增高 ,组织中 SOD活性和动物 2 4小时存活率显著降低 ,有统计学意义(P<0 .0 5 ) ;I/ R Zn PP组与 I/ R组相比各脏器 MDA含量进一步增高 ,血液内 COHb水平、组织中 SOD活性和动物的2 4小时存活率显著降低 ,也有统计学意义 (P<0 .0 5 )。结论　肢体缺血再灌注可导致多器官的氧化性损伤 ,并使 CO产生增多 ,后者在大鼠抗缺血再灌注所致的远隔多器官损伤中具有重要作用。     

PEP-1介导血红素加氧酶-1对大鼠肝脏缺血／再灌注后SOD和MDA及Caspase-3表达的影响

目的：探讨大鼠肝缺血/再灌注（I/R）后PEP-1介导血红素加氧酶-1（HO-1）对肝脏超氧化物歧化酶（SOD）、丙二醛（MDA）及caspase-3的影响。方法制作肝I/R损伤动物模型,SD大鼠随机分为4组,即假手术组（S组）,肝缺血再灌注组（I/R组）、HO-1组、PEP-1-HO-1组。I/R后12 h光镜及电镜下观察肝细胞病理学改变,检测血清ALT的水平、肝组织MDA的含量及SOD的活性,免疫组化染色检测肝组织caspase-3的表达。结果 PEP-1-HO-1组血清ALT、肝组织MDA变化幅度明显低于I/R组,肝组织SOD明显高于I/R组（P ＜0．05）。在电镜下观察,l/R组肝小叶结构紊乱,肝窦淤血,肝细胞水肿变性,肝细胞片状坏死。HO-1组和PEP-1-HO-1组上述改变明显减轻。在I/R组中,caspase-3较S组表达增强,而在HO-1组、PEP-1-HO1组中其表达较I/R组减弱。结论 PEP-1介导HO-1对肝I/R损伤有保护作用,其作用机制可能与减少氧自由基产生、减轻脂质过氧化反应及抑制caspase-3的表达有关。     

Protective effect of hemoglobin—induced heme oxygenase—1 on injured lungs caused by limb ischemia—reperfusion in rats

OBJECTIVE: To determine the role of hemoglobin (HB) induced heme oxygenase-1 (HO-1) in injured lungs caused by limb ischemia-reperfusion (I/R) in rats. METHODS: A rat model of ischemia in the hind limbs was made by clamping the infrarenal aorta with a microvascular clip, and lung injury occurred after reperfusion. To induce the expression of HO-1 in the lungs, Hb was administrated intraperitoneally at 16 hours before reperfusion. Northern blotting and Western blotting were used to detect the expression of HO-1 in the lungs, and the carboxyhemoglobin (COHb) level in arterial blood was assayed. The effect of hemoglobin (Hb) on the injured lungs after limb I/R was determined by measuring the changes of lung histology, polymorphonuclear (PMN) count, malondialdehyde (MDA) content and wet-to-dry weight ratio (W/D). Zinc protoporphyrin (ZnPP), an inhibitor of HO, was used to determine whether HO-1 was induced by Hb after lung injury. RESULTS: Hb led to a significant increase in HO-1 mRNA and protein expression in the lungs, accompanied by the increase of COHb level in arterial blood. Compared with the sham controls, the lung PMN count, MDA content and W/D significantly increased at 4 hours after limb I/R, which reversed by the pretreatment with Hb at 16 hours before reperfusion. ZnPP blocked this protective role of Hb in the injured lungs. CONCLUSIONS: Hb can induce the lung HO-1 expression, which plays an important role in the defense against I/R induced lung injury in rats.     

缺血预处理对大鼠缺血再灌注心肌HIF-1α和HO-1的影响

目的 探讨缺血预处理对大鼠缺血再灌注心肌低氧诱导因子1α(HIF-1α)和血红素加氧酶1(HO-1)的影响.方法 健康雄性SD大鼠48只,体重220～280 g,随机分为4组(n=12):假手术组(S组)、缺血再灌注组(IR组)、缺血预处理+缺血再灌注组(IP组)和缺血预处理+缺血再灌注+HO-1抑制剂组(HI组).采用结扎左冠状动脉前降支30 min再灌注120 min的方法建立心肌缺血再灌注模型.S组仅在冠状动脉下穿线;IP组于缺血前采用结扎/放松左冠状动脉前降支各5 min,重复3次的方法行缺血预处理;HI组于缺血预处理前1 d腹腔注射锌原卟啉Ⅸ 10 ms/ks,其余同IP组.于再灌注结束时测定心肌HIF-1α、HO-1的mRNA和蛋白表达、HO-1活性、SOD活性及MDA含量,计算心肌梗死面积,取动脉血样测定血清TNF-α和IL-6的浓度.结果 与S组比较,IR组、IP组和HI组心肌SOD活性降低,MDA含量升高,血清TNF-α和IL-6的浓度升高(P＜0.01);与IR组比较,IP组心肌SOD活性升高,MDA含量降低,血清TNF-α和IL-6浓度降低,心肌HIF-1α和HO-1的mRNA和蛋白表达上调,HO-1活性升高,心肌梗死面积减小(P＜0.01);与IP组比较,HI组心肌SOD活性降低,MDA含量升高,血清TNF-α和IL6浓度升高,心肌HO-1的mRNA和蛋白表达下调,HO-1活性降低,心肌梗死面积增加(P＜0.05或0.01),心肌HIF-1α的mBNA和蛋白表达差异无统计学意义(P＞0.05).结论 缺血预处理减轻大鼠心肌缺血再灌注损伤的机制与HIF-1α诱导HO-1活性增强有关.     

Ischemic postconditioning protects renal function after 24 hours of cold preservation in a canine autotransplantation model

Objectives

Ischemia-reperfusion (I/R) injury is the most common cause of renal dysfunction. Ischemic postconditioning (IPO) is a phenomenon by which intermittent interruptions of blood flow in the early phase of reperfusion protect an organ from I/R injury. In the present study, we investigated the effects of IPO on renal I/R injury using a canine autotransplantation model.

Materials and methods

Fifty adult male mongrel dogs were randomly divided into five groups of 10 animals each. The animals underwent a left nephrectomy followed by flushing and static preservation of the kidney in University of Wisconsin solution for 24 hours. IPO was performed by six cycles of 10 or 30 seconds or three cycles of 1-minute I/R before final reperfusion. All dogs underwent a right nephrectomy 24 hours later followed by autotransplantation of the preserved left kidney. Blood and urine were collected at various reperfusion times (24, 48, and 72 hours). We assayed blood urea nitrogen and creatinine levels, as well as urine N-acetyl-β-D-glucosaminidase levels. Kidney samples were harvested after I/R to measured renal superoxide dysmutase (SOD), malondialdehyde (MDA), and myeloperoxidase (MPO) concentrations. Apoptosis was evaluated by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling assays of tissue samples.

Results

Compared with the sham group, I/R resulted in renal dysfunction with decreased SOD and increased MDA and MPO levels, as well as increased apoptosis indices. However, IPO attenuated the above effects, particularly the six cycles of 10-second I/R.

Conclusions

IPO exerted protective effects on renal I/R injury.     

The Protective Effect of Aprotinin and α-Tocopherol on Ischemia-Reperfusion Injury of the Rat Liver

Background

Liver injury caused by ischemia-reperfusion (I/R) processes is a complication of hepatic resection surgery and transplantation, particularly using grafts from marginal donors. Despite improvements in organ preservation and advances in surgical techniques, I/R injury remains a significant clinical problem. In this study, we investigated whether aprotinin provided protection against the adverse effects of I/R injury in liver tissue.

Methods

Forty rats were randomized into four groups (n = 10): group I: (control group) I/R + no medication; group II: sham-operated group + no medication or I/R; group III: I/R + aprotinin; group IV: I/R + α-tocopherol. Malondialdehyde (MDA) was measured in the liver tissue and superoxide dismutase (SOD), catalase (CAT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), as well as lactate dehydrogenase (LDH) in rat serum.

Results

Administration of aprotinin and α-tocopherol before I/R resulted in significant reductions of MDA levels compared to the I/R alone group (group I; P = .01 and P < .01, respectively). Administration of aprotinin or α-tocopherol prior to I/R resulted in significant increases in SOD and CAT levels compared with the I/R group (P < .05 each). Compared to the I/R group, significant decreases in plasma AST, ALT, and LDH levels were observed both in the aprotinin and in the α-tocopherol group (P < .05). Histological evaluation revealed the injury grade to be relatively lower among groups III and IV compared to group I.

Discussion

In conclusion, rat hepatic structures in aprotinin and α-tocopherol administered groups were well protected. Therefore, aprotinin may provide protection against the adverse effects of I/R injury in liver transplantation.     

Transient limb ischemia induces remote preconditioning in liver among rats: the protective role of heme oxygenase-1

BACKGROUND: We have reported the protective role of heme oxygenase-1 (HO-1) in the mechanism of hypoxic preconditioning. We wish to investigate the role of HO-1 in remote preconditioning (RP) against hepatic ischemia/reperfusion (I/R) injury in rats. METHODS: The remote preconditioning was produced by four cycles of 10-min ischemia-reperfusion of the hind limb of rats. Partial hepatic ischemia was produced in the left lobes for 45 min followed by 240 min of reperfusion. Zinc-protoporphyrin IX (ZnPP), a specific inhibitor of HO enzymatic activity, was intra-peritoneally injected 1 hr before the ischemia-reperfusion injury in separate groups of RP rats. Serum alanine transaminase (ALT) levels, expression of hepatic HO-1 protein and mRNA, immunohistochemical staining and HO enzymatic activity were measured. RESULTS: HO-1 was induced in the livers of rats 4 hr after the RP stimuli, and the overexpression persisted for 24 hr. Immunohistochemical staining demonstrated induction of HO-1 in the hepatocytes. The peripheral lymphocytes did not express HO-1 after RP. RP diminished the elevation of serum ALT levels 4 hr after I/R injury (283.7+/-167.4 U L) when compared with controls (1297.7+/-729.3 U L) and RP+ ZnPP pretreated groups (1429.9+/-750.9 U L). The heme oxygenase activity in treated rats also correlated these results (286.8+/-34.3 pmol mg protein hr for the RP group, 156.3+/-27.5 pmol mg protein hr for the RP+ ZnPP pretreated group, and 170.6+/-19.4 pmol mg protein hr for the control group, 144.8+/-7.8 pmol mg protein hr for the control+ ZnPP pretreated group). CONCLUSION: Our results indicated that the induction of HO-1 in remote preconditioning played a protective role against hepatic I/R injury.     

Effect of neferine on liver ischemia-reperfusion injury in rats

Introduction

Liver ischemia/reperfusion leads to the formation of reactive oxygen species (ROS) that cause liver injury, a critical clinical problem during liver surgery and transplantation. The aim of the present study was to investigate the hepatoprotective and antioxidant effects of neferine against liver ischemia/reperfusion injury in rats.

Materials and Methods

Wistar rats were randomly divided into 4 groups (n = 8): sham group; model group, and neferine high and low groups (50 and 25 mg/kg, respectively). After either saline or neferine was orally administered for 5 days rat livers were subjected to 30 minutes of ischemia followed by 6 hours of reperfusion. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and hydroxyl radical levels were measured in serum. The liver was removed to assay malondialdehyde (MDA) and carbonyl contents, superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities, as well as to evaluate histopathologic changes.

Results

Neferine significantly prevented AST and ALT elevations, reduced hydroxyl radical release, inhibited SOD and GPx activities, and decreased MDA and carbonyl contents. At the same time, neferine attenuated the histopathologic changes.

Conclusion

Neferine protected against liver ischemia/reperfusion in rats through antioxidant mechanisms. However, further studies are needed to verify whether the hepatoprotection of neferine is correlated with anti-inflammatory and anti-apoptotic effects.     

不同时间的缺血预处理对肝硬化大鼠缺血再灌注损伤的保护作用

目的 探讨缺血预处理(IPC)对肝硬化大鼠缺血再灌注损伤(I/R)的保护作用,并寻找对肝硬化I/R保护作用的最佳有效时间窗和理想方案.方法 通过构建正常大鼠及肝硬化大鼠模型,以正常肝脏I/R(A组)和正常肝脏10-10 min-IPC方案(B组)为对照组,肝硬化组则分别施行单纯I/R(C组)、5-10 min(D组)、8-10min(E组)、10-10 min(F组)及15-10 min(G组)的IPC方案,每组18只,分别在术后1 h、4 h及24 h三个时间点采静脉血,检测血清ALT、AST、LDH及肝组织中MDA、MPO、NO、SOD水平,评价肝功能及肝脏组织炎性浸润及抗损伤程度.结果 肝脏缺血30 min后肝脏功能受损明显,表现为各组的ALT、AST、LDH水平升高,尤以再灌注4 h时显著(P<0.05),但经过缺血预处理后,各IPC组中的NO、MDA、MPO及SOD水平亦显著高于其对应的I/R组,以E组的差别有显著意义(P<0.05).结论 10-10 min的IPC方案对于正常肝脏I/R确有保护作用,而8-10 min的IPC方案能最有效地启动对肝硬化大鼠肝脏I/R的保护作用.     

细胞穿透肽PEP-1介导血红素加氧酶-1对大鼠肠缺血再灌注损伤的影响

目的 评价细胞穿透肽PEP-1介导血红素加氧酶-1(HO-1)对大鼠肠缺血再灌注损伤的影响.方法 雄性SD大鼠18只,周龄7～9周,体重210～260 g,采用随机数字表法,将大鼠随机分为3组(n=6):假手术组(S组)、肠缺血再灌注组(IR组)和融合蛋白PEP-1/HO-1+肠缺血再灌注组(HO组).采用夹闭肠系膜上动脉45 min,恢复灌注120 min的方法制备大鼠肠缺血再灌注损伤模型.HO组夹闭肠系膜上动脉前30 min,左侧髂静脉注射融合蛋白PEP-1/HO-1 0.5 mg,S组不夹闭肠系膜上动脉,余操作同IR组.于再灌注120 min时处死大鼠取小肠组织,称重后计算肠湿/干重比,测定丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性和HO-1活性,免疫组化法检测肠组织HO-1蛋白的表达,光镜下观察肠组织结构并进行损伤评分.结果 与S组比较,IR组和HO组肠湿/干重比和MDA含量升高,SOD活性降低,HO-1活性和蛋白表达水平升高,损伤评分升高(P＜0.05);与IR组比较,HO组肠湿/干重比、MDA含量降低,SOD活性升高,HO-1活性和蛋白表达水平升高,损伤评分降低(P＜0.05).HO组大鼠肠组织病理学损伤较IR组减轻.结论 细胞穿透肽PEP-1可将HO-1成功导人大鼠肠组织中的细胞并减轻肠缺血再灌注损伤.

Abstract：

Objective To investigate the effects of heme oxygenase-1 (HO-1) mediated by cell penetrating peptide PEP-1 on intestinal ischemia/reperfusion (I/R) injuiy in tats. Methods Eighteen male SD rats aged 7-9 weeks weighing 210-260 g were randomly divided into 3 groups (re = 6 each): sham operation group (group S) , I/R group and PEP-1/HO-1 + I/R group (group HO) . To establish a model of intestinal I/R injury, intestines were exteriorized and the superior mesenteric artery was exposed and occluded for 45 min ischemia, and then the clamp was removed for 120 min reperfusion. The PEP-1/HO-1 fusion protein 0.5 mg was injected via the left iliac vein 30 min prior to ischemia in group HO. The superior mesenteric artery was exposed but not occluded in group S. At the end of reperfusion, the rats were sacrificed and intestinal tissues obtained to determine the intestinal wet/ dry ratio, malondialdehyde (MDA) level, activities of superoxide dismutase (SOD) and HO-1, and HO-1 protein expression. The histological changes in the intestinal mucosa were examined and the injuiy was scored. Results Compared with group S, the intestinal wet/dry ratio, MDA level, HO-1 activity, HO-1 protein expression and injury score were significantly increased, while the SOD activity was significantly decreased in groups I/R and HO ( P ＜ 0.05) . Compared with group I/R, the intestinal wet/dry ratio, MDA level and injury score were significantly decreased, while the SOD activity, HO-1 activity and HO-1 protein expression increased in group HO ( P ＜ 0.05) . The pathologic changes were significantly attenuated in group HO compared with group I/R.Conclusion HO-1 protein can be successfully delivered into intestinal tissues by PEP-1 and has protective effects against intestinal I/R injury.     

Effects of the Antioxidants Lycium Barbarum and Ascorbic Acid on Reperfusion Liver Injury in Rats

Objective

Ischemia/reperfusion (I/R) of the rat liver can induce liver injury through mechanisms involving oxidative and nitrosative stresses. In this study we examined the effects of antioxidants Lycium barbarum (LB) and ascorbic acid on I/R-induced liver injury in rats.

Methods

Liver ischemia was induced by clamping the common hepatic artery and portal vein of rats for 40 minutes. Thereafter, flow was restored with reperfusion for 90 minutes. Blood samples collected before ischemia and after reperfusion were analyzed for alanine transaminase (ALT), lactic dehydrogenase (LDH), hydroxyl radical, and nitric oxide (NO) levels. Pharmacologic interventions included administration of ascorbic acid (100 mg/kg, i.p., 1 hour before I/R) or LB, an extract of Gogi berries: 600 mg in 100 mL of drinking water for 2 weeks prior to experimentation.

Results

This protocol resulted in elevation of blood concentrations of NO, hydroxyl radical, ALT, and LDH (P < .001) in the I/R-induced liver injury group. Ascorbic acid significantly attenuated the reperfusion liver injury by attenuating hydroxyl radical (P < .01) and NO (P < .05) release. The LB aggravated I/R-induced liver injury by increasing hydroxyl radical release with no effect on NO release.

Discussion and conclusions

This I/R protocol resulted in oxidative and nitrosative stress and liver injury. Ascorbic acid showed significant protective effects on reperfusion liver injury by attenuating hydroxyl radical and NO release. In contrast, LB aggravated liver injury by increasing hydroxyl radical release.     

Protective effects of pretreatment with Radix Paeoniae Rubra on acute lung injury induced by intestinal ischemia/reperfusion in rats

Objective： To investigate the effect of pretreatment with Radix Paeoniae Rubra （RPR） on acute lung injury induced by intestinal ischemia/reperfusion in rats and its protective mechanism.
Methods： Thirty-two Wistar rats were randomly divided into four groups： Sham-operation group, ischemla/ reperfusion group （I/R group ）, RPR-pretreatment group and hemin group. The model of intestinal ischemia/ reperfusion was established by clamping the superior mesenteric artery for 1 hour followed by 2-hour reperfusion. The effect of RPR on the expression of heme oxygenase-1 （HO-1） in lung tissues was detected by immunohistochemistry and morphometry computer image analysis. Arterial blood gas analysis, lung permeability index, malondialdehyde （MDA） and superoxide dismutase （SOD） contents in lungs were measured. The histological changes of lung tissue were observed under light microscope.
Resalts： The expression of HO-1 in RPR-pretreatment group and hemin group was obviously higher than that in sham-operation group and I/R group （ P 〈 0.01 ）. The level of MDA and lung permeability index in RPR-pretreatment and hemin group were significantly lower than those in I/R group （P〈0.01 or P〈0.05）, while the activity of SOD in RPR-pretreatment and hemin group was obviously higher than that in I/R group （P〈0.01）. Under light microscope, the pathologic changes induced by I/R were significantly attenuated by RPR.
Conclusion： Intestinal ischemia/reperfusion may result in acute lung injury and pretreatment with RPR injection can attenuate the injury. The protective effect of RPR on the acute lung injury is related to its property of inducing HO-1 expression and inhibiting lipid peroxidation.     

乌司他丁对大鼠原位肝脏移植供肝的保护作用

目的：探讨乌司他丁对大鼠原位肝脏移植供肝的保护作用及机制。 方法：分别用单纯UW液（模型组）或含乌司他丁（乌司他丁组）、HO-1诱导剂CoPP（CoPP组）、HO-1抑制剂ZnPP（ZnPP组）的UW液灌注切取的供体大鼠肝脏并保留灌注液1 h后,原位移植受体大鼠。移植后24 h取移植肝脏与受体大鼠血标本,行肝脏病理学检查及评分;分别用real-time PCR和Western bolt法检测肝组织HO-1 mRNA与蛋白的表达;用Elisa法检测大鼠血清中IL-2和IL-10的含量。 结果：与模型组比较,乌司他丁组与CoPP组供肝的损伤明显减轻、Suzuki评分降低,而ZnPP组损伤加重、Suzuki评分升高（均P<0.05）;乌司他丁组与CoPP组HO-1 mRNA与蛋白的表达明显上调,而ZnPP组明显下调（均P<0.05）;乌司他丁组与CoPP组大鼠血清中IL-2水平明显降低、IL-10水平明显升高,而ZnPP组IL-2水平明显升高、IL-10水平明显降低（均P<0.05）。 结论：乌司他丁可能通过上调移植大鼠肝脏的HO-1水平,减轻再灌注损伤、抑制排斥反应而发挥保护作用。