Gender differences in hepatic ischemic reperfusion injury in rats are associated with endothelial cell nitric oxide synthase-derived nitric oxide

AIM: This study was designed to examine the hypothesis that gender differences in I/R injury are associated with endothelial cell nitric oxide synthase (eNOS)-derived nitric oxide (NO). METHODS: Wistar rats were randomized into seven experimental groups (12 animals per group). Except for the sham operated groups, all rats were subjected to total liver ischemia for 40 min followed by reperfusion. All experimental groups received different treatments 45 min before the laparotomy. For each group, half of the animals (six) were used to investigate the survival; blood samples and liver tissues were obtained in the remaining six animals after 3 h of reperfusion to assess serum NO, alanine aminotransferase (ALT) and TNF-α levels, liver tissue malondialdehyde (MDA) content, and severity of hepatic I/R injury. RESULTS: Basal serum NO levels in female sham operated (FS) group were nearly 1.5-fold of male sham operated (MS) group (66.7±11.0 μmol/L vs45.3μ10.1 μmol/L, P<0.01). Although serum NO levels decreased significantly after hepatic I/R (P<0.01, vs sham operated groups), they were still significantly higher in female rat (F) group than in male rat (M) group (47.8±8.6 μmol/L vs 23.8±4.7 μmol/L, P<0.01). Serum ALT and TNF-α levels, and liver tissue MDA content were significantly lower in F group than in M group (370.5±46.4 U/L, 0.99±0.11 μg/L and 0.57±0.10 μmol/g vs668.7±78.7 U/L, 1.71±0.18μg/L and 0.86±0.11 μmol/g, respectively, P<0.01). I/R induced significant injury to the liver both in M and F groups (P<0.01 vs sham operated groups). But the degree of hepatocyte injury was significantly milder in F group than in M group (P<0.05 and P<0.01). The median survival time was six days in F group and one day in M group. The overall survival rate was significantly higher in F group than in M group (P<0.05). When compared with male rats pretreated with saline (M group), pretreatment of male rats with 17-β-estradiol (E2) (M+E2 group) significantly increased serum NO levels and significantly decreased serum ALT and TNF-α levels, and liver tissue MDA content after I/R (P<0.01). The degree of hepatocyte injury was significantly decreased and the overall survival rate was significantly improved in M+E2 group than in M group (P<0.01 and P<0.05). The NOS inhibitor Nw-nitro-L-arginine methyl ester (L-NAME) treatment could completely abolish the protective effects of estrogen in both male and female rats. CONCLUSION: The protective effects afforded to female rats subjected to hepatic I/R are associated with eNOS-derived NO.     

Heme oxygenase-1 alleviates ischemia／reperfusion injury in aged liver

AIM: To investigate if ischemia/reperfusion (I/R) injury in aged liver could be alleviated by heme oxygenase-1 (HO-1). METHODS: Three groups of SD rats (16 mo old) were studied. Group 1: control donors received physiological saline 24 h before their livers were harvested; group 2: donors were pretreated with hemih 24 h before their livers were harvested; and group 3: donors received hemin 24 h before their livers were harvested and zinc protoporphyrin (ZnPP, HO-1 inhibitor) was given to recipients at reperfusion. The harvested livers were stored in University of Wisconsin solution (4℃) for 6 h, and then transplanted to syngeneic rats. Serum glutamic oxaloacetic transaminase (SGOT), apoptotic cells, and apoptotic gene were measured 3, 6, 12, 24, 48 h after reperfusion. We measured the apoptotic index by TUNEL, determined the expression of antiapoptotic Bcl-2 and proapoptotic (caspase-3) gene products by Western blot.. RESULTS: After 3, 6, 12, 24, and 48 h of reperfusion, the SGOT levels (584.4±85.8 u/L, 999.2±125.2 u/L, 423.4±161.3 u/L, 257.8±95.8 u/L, and 122.4±26.4 u/L) in hemin group were significantly (all P<0.05) lower than those in saline group (1082.2±101.2 u/L, 1775.2±328.3 u/L, 840.4±137.8 u/L, 448.6±74.3 u/L, and 306.2±49.3 u/L). Liver HO-1 enzymatic activity correlated with beneficial effects of hemin and deleterious effects of adjunctive ZnPP treatment. Markedly less apoptotic (TUNEL+) liver cells 3, 6,12, 24, and 48 h after reperfusion (5.16±0.73, 10.2±0.67, 9.28±0.78, 7.14±1.12, and 4.78±0.65) (P<0.05) could be detected in hemin liver grafts, as compared to controls (7.82±1.05, 15.94±1.82, 11.67±1.59, 8.28±1.09, and 6.36±0.67). We detected the increased levels of Bcl-2 (1.5-fold) expression and compared with saline controls. These differences were most pronounced at 12 h after transplantation. In contrast, an active form of proapoptotic caspase-3 (p20) protein was found to be 2.9-fold lower at 24 h in hemin-pretreated group, as compared to saline liver transplant controls. CONCLUSION: HO-1 overexpression can provide potent protection against cold I/R injury. This effect depends, at least in part, on HO-1-mediated inhibition of antiapoptotic mechanism.     

Protection of Veratrum nigrum L. var. ussuriense Nakai alkaloids against ischemia-reperfusion injury of the rat liver

AIM： TO investigate the protective effects and possible mechanisms of Veratrum nigrum L. var. ussuriense Nakai alkaloids （VnA） on hepatic ischemia/reperfusion （I/R） injury in rats.
METHODS： Forty male Wistar rats were randomly divided into four experimental groups （n = 10 in each）： （A） Control group （the sham operation group）; （8） I/R group （pretreated with normal saline）; （C） Small-dose （10 μg/kg） VnA pretreatment group; （D） Large-dose （20 μg/kg） VnA pretreatment group. Hepatic ischemia/ reperfusion （Hepatic I/R） was induced by occlusion of the portal vein and the hepatic artery for 90 min, followed by reperfusion for 240 min. The pretreatment groups were administered with VnA intraperitoneally, 30 min before surgery, while the control group and I/R group were given equal volumes of normal saline. Superoxide dismutase （SOD） activity, myeloperoxidase （MPO） activity and nitric oxide （NO） content in the liver tissue at the end of reperfusion were determined and liver function was measured. The expression of intercellular adhesion molecule-1 （ICAM-1） and E-selectin （ES） were detected by immunohistochemical examinations and Western blot analyses.
RESULTS： The results showed that hepatic I/R elicited a significant increase in the plasma levels of alanine aminotransferase （ALT： 74.53 ± 2.58 IU/L vs 1512.54 ± 200.76 IU/L, P 〈 0.01） and lactic dehydrogenase （LDH： 473.48 ± 52.17 IU/L vs 5821.53 ± 163.69 IU/L, P 〈 0.01）, as well as the levels of MPO （1.97 ± 0.11 U/g vs 2.57 ± 0.13 U/g, P 〈 0.01） and NO （69.37 ± 1.52 μmol/g protein vs 78.39 ± 2.28 μmol/g protein, P 〈 0.01） in the liver tissue, all of which were reduced by pretreatment with VnA, respectively （ALT： 1512.54 ± 200.76 IU/L vs 977.93 ± 89.62 IU/L, 909.81 ± 132.76 IU/L, P 〈 0.01, P 〈 0.01; LDH： 5821.53 ± 163.69 IU/L vs 3015.44 ± 253.01 IU/L, 2448.75 ± 169.4 IU/L, P 〈 0.01, P 〈 0.01; MPO： 2.57 ± 0.13 U/g vs 2.13 ± 0.13 U/g,     

实验性肝硬化大鼠肺脏血红素氧合酶的表达与定位

目的 观察肝硬化大鼠肺脏中血红素氧合酶(HO)的表达与定位,探讨血红素氧合酶-内源性一氧化碳在肝硬化时肺脏病变的作用。方法 建立四氯化碳肝硬化模型,应用免疫组织化学法和免疫印迹法对肝硬化大鼠和正常对照大鼠肺脏中血红素氧合酶的表达与定位进行比较。 结果 肝硬化模型制备成功。正常对照组大鼠HO-1在肺组织的表达较低,而肝硬化组大鼠的肺组织中HO-1蛋白表达明显增高(0.062±0.021与0.185±0.044,t=11.24,P<0.01 ;0与5 294.92±46.02,t=11.45,P<0.01),主要在血管和支气管的平滑肌细胞,内皮细胞及气道上皮细胞的胞浆内,而HO-2在两组大鼠的肺组织中表达差异无显著性(0.218±0.048与0.238±0.079,t=0.99,P>0.05; 5984.17±35.64与6040.75±42.43,t=0.02,P>0.05)。 结论 血红素氧合酶-内源性一氧化碳途径可能在肝硬化肺脏病变的发生机制中起一定的作用。     

一氧化碳体系对慢性肺心病大鼠肺血管结构重建的抑制作用

目的　研究内源性一氧化碳体系对慢性肺心病肺血管结构重建的调控作用。方法　将36只SD大鼠随机分为正常对照组 (A组 )、4周低O2 高CO2 组 (B组 ) ,4周低O2 高CO+ 2 血晶素组 (C组 ) ,每组 12只。测定各组大鼠肺动脉平均压 (mPAP)、右心室 / (左心室 +室间隔 )重量比 [RV/ (LV +S) ]、肺细小动脉显微和超微结构、血CO浓度、血清及肺组织匀浆上清液血红素氧合酶 1(HO 1)活性和肺细小动脉HO 1及其基因表达的变化。结果　 (1)B组mPAP为 (2 0 1± 0 8)mmHg(1mmHg =0 .133kPa)、RV/ (LV +S)为 (35 5± 1 7) %、与A组 [(15 3± 1 4 )mmHg、(2 6 7± 1 7) % ]及C组[(16 5± 3 7)mmHg、(30 2± 1 6 ) % ]比较差异有显著性 (P均 <0 0 1)。 (2 )B组肺细小动脉血管结构重建的显微形态测定指标与A、C组比较差异也有显著性 (P <0 0 1)。 (3)B组全血CO含量、血清及肺组织匀浆HO 1活性、肺细小动脉HO 1及其mRNA分别为 (2 1± 0 9) %、(73± 18)nmol·L-1·h-1、(175 1± 311)pmol·mg-1·h-1、0 191± 0 0 12和 0 30 1± 0 0 17,与A组 [(0 5± 0 3) %、(2 5± 8)nmol·L-1·h-1、(385± 4 6 )pmol·mg-1·h-1、0 0 5 9± 0 0 0 5、0 131± 0 0 11]和C组 [(4 9± 2 1) %、(132±39)nmol·L-1·h-1     

Effects of ketamine on proinflammatory cytokines and nuclear factor kappaB in polymicrobial sepsis rats

INTRODUCTION Sepsis/Septic shock is a complex pathophysiologic process characterized by profound hypotension, progressive metabolic acidosis, systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), and even death. Altho…     

Cholestasis enhances liver ischemia/reperfusion‐induced coagulation activation in rats

Aim: Cholestasis is associated with increased morbidity and mortality in patients undergoing major liver surgery. An additional risk is induced when vascular inflow occlusion is applied giving rise to liver ischemia/reperfusion (I/R) injury. The role of the coagulation system in this type of injury is elusive. The aim of the current study was to assess activation of coagulation following hepatic I/R injury in cholestatic rats. Methods: Male Wistar rats were randomized into two groups and subjected to bile duct ligation (BDL) or sham laparotomy. After 7 days, both groups underwent 30 min partial liver ischemia. Animals were sacrificed before ischemia or after 6 h, 24 h, and 48 h reperfusion. Results: Plasma AST and ALT levels were higher after I/R in cholestatic rats (P < 0.05). Hepatic necrosis, liver wet/dry ratio and neutrophil influx were increased in the BDL group up to 48 h reperfusion (P < 0.05). Liver synthetic function was decreased in the BDL group as reflected by prolonged prothrombin time after 6 h and 24 h reperfusion (P < 0.05). I/R in cholestatic rats resulted in a 12‐fold vs. 7‐fold (P < 0.01) increase in markers for thrombin generation and a 6‐fold vs. 2‐fold (P < 0.01) increase in fibrin degradation products (BDL vs. control, respectively). In addition, the cholestatic rats exhibited significantly decreased levels of antithrombin (AT) III and increased levels of the fibrinolytic inhibitor plasminogen activator inhibitor (PAI‐1) during reperfusion. Conclusions: Cholestasis significantly enhances I/R‐induced hepatic damage and inflammation that concurs with an increased activation of coagulation and fibrinolysis.     

Protective role of an endothelin-converting enzyme inhibitor (FR901533) in hepatic ischemia/reperfusion injury.

INTRODUCTION: There is evidence that endothelin (ET) contributes to disturbances of the hepatic microcirculation after warm ischemia/reperfusion (I/R) by causing vasoconstriction and by enhancing leukocyte endothelium interactions. The aim of this study was to investigate a possible protective role of the endothelin converting enzyme (ECE) inhibitor FR901533 in this setting. METHODS: In an in vivo model (42 Wistar rats), hepatic ischemia was induced for 30 min by Pringle's maneuver. Sham operated (I), untreated ischemic (II), and treatment (III) groups with FR901533 (1 mg/kg bw iv) were investigated. The effect of FR901533 in I/R was assessed by in vivo microscopy (30-90 min after reperfusion), measurement of local tissue pO2 (30 and 60 min after reperfusion), and determination of AST/ALT levels (2 h, 6 h, and 2, 6, and 14 days after reperfusion). RESULTS: In the untreated ischemic group (II) sinusoidal constriction to 76.3 +/- 4.2% of basic diameters was observed, leading to significant decreases in perfusion rate (82.3 +/- 3.6% of sham group) and in liver tissue pO(2) (43.5 +/- 3.2% of sham group) (P < 0.05). In addition, we found an increased percentage of stagnant leukocytes in sinusoids (138.3 +/- 9.8) and sticking leukocytes in postsinusoidal venules (155.2 +/- 3.3% of sham group) (P < 0.05). Hepatocellular damage (AST/ALT increase to 430.6 +/- 47.7 U/L/200.2 +/- 23.8 U/L, pre: 27.4 +/- 2.7 U/L/28.1 +/- 2.7 U/L) was detected 6 h after reperfusion (P < 0.05). Administration of the ECE inhibitor before ischemia significantly reduced I/R injury. Sinusoidal diameters were maintained (102.2 +/- 1.7%), while perfusion rate (93.1 +/- 1.8%) and tissue pO2 (105.3 +/- 2.7%) increased significantly (P < 0.05). Hepatocellular damage was decreased (AST/ALT levels after 6 h of reperfusion: 166.6 +/- 26.3 U/L/132.4 +/- 22.5 U/L, P < 0.05) and leukocyte sticking and rolling were significantly reduced (P < 0.05). CONCLUSION: Our results provide evidence that the new therapeutic approach with an ECE inhibitor is effective in reducing hepatic I/R injury.     

Effect of ischemic preconditioning on P-selectin expression in hepatocytes of rats with cirrhotic ischemia-reperfusion injury

AIM: To investigate the effects and mechanisms of ischemic preconditioning (IPC) on the ischemia/reperfusion (I/R) injury of liver cirrhosis in rats and the effect of IPC on P-selectin expression in hepatocytes.METHODS: Forty male SD rats with liver cirrhosis were randomly divided into sham operation group (SO group),ischemia/reperfusion group (I/R group), ischemic preconditioning group (IPC group), L-Arginine preconditioning group (APC group), L-NAME preconditioning group (NPC group), eight rats in each group. Hepatocellular viability was assessed by hepatic adenine nucleotide level and energy charge (EC) determined by HPLC, ALT, AST and LDH in serum measured by auto- biochemical analyzer and bile output.The expression of P-selectin in the liver tissue was analyzed by immunohistochemical technique. Leukocyte count in ischemic hepatic lobe was calculated.RESULTS: At 120 min after reperfusion, the level of ATP and EC in IPC and APC groups was higher than that in I/R group significantly. The increases in AST, ALT and LDH were prevented in IPC and APC groups. The livers produced more bile in IPC group than in I/R group during 120 min after reperfusion (0.101±0.027 versus 0.066±0.027 ml/g liver,P=0.002). There was a significant difference between APC and I/R groups, (P=0.001). The leukocyte count in liver tissues significantly increased in I/R group as compared with SO group (P＜0.05). The increase in the leukocyte count was prevented in IPC group. Administration of L-arginine resulted in the same effects as in IPC group. However,inhibition of NO synthesis (NPC group) held back the beneficial effects of preconditioning. Significant promotion of P-selectin expression in hepatocytes in the I/R group was observed compared with the SO group (P＜0.01). IPC or L-arginine attenuated P-selectin expression remarkably (P＜0.01). However, inhibition of NO synthesis enhanced Pselectin expression (P＜0.01). The degree of P-selectin expression was positively correlated with the leukocyte counts infiltrating in liver (r=0.602, P=0.000).CONCLUSION: IPC can attenuate the damage induced by I/R in cirrhotic liver and increase the ischemic tolerance of the rats with liver cirrhosis. IPC can abolish I/R induced leukocyte adhesion and infiltration by preventing postischemic P-selectin expression in the rats with liver cirrhosis via a NO-initiated pathway.     

联合测定吲哚箐绿和D-山梨醇评价肝储备功能

目的 利用高效液相法(HPLC)测定正常肝脏和肝硬化肝脏的吲哚箐绿(ICG)肝固有代谢容量,并结合D-山梨醇无创测量肝功能性血流量、肝内分流率,全面评价肝储备功能。方法 制作大鼠肝硬化模型和肝脏隔离灌注模型,据HPLC法和Bergmeyer酶分光光度法分别测量ICG和D-山梨醇的药代动力学参数。结果 (1)HPLC证实ICG包括ICG原形(ICGg)和ICG降解产物(ICGdp)两种成分,保留时间分别为8.9min和24.2min,两种成分光谱相似,但体内代谢不同。(2)据ICGg计算的肝固有代谢容量(Q_(INT,I))在对照组和肝硬化组分别为(36.57±13.03)ml/min和(14.39±5.13)ml/min,肝硬化组Q_(INT,I)明显下降(t=7.08,P<0.01)。(3)肝功能性血流量(Q_(FUNC)),肝内分流率(Q_(IHS))在对照组和肝硬化组分别为:(34.06±5.12)ml/min和(17.54±7.02)ml/min,(9.9±1.4)％和(47.5±20.9)％,肝硬化组Q_(FUNC)显著下降(t=8.41,P<0.01),Q_(IHS)显著增加(t=8.35,P<0.01)。结论(1)HPLC法可避免ICGdp的干扰,优于传统的分光光度法,能用于肝固有代谢容量测定。(2)D-山梨醇肝清除率,是无创测定正常肝脏的总血流量,和肝硬化肝脏的肝功能性血流量、肝内分流率的实用可靠方法。(3)ICG与D-山梨醇联合使用,有助于全面评价肝脏功能状态。     

重组人可溶性补体受体1型SCR15-18片段对心肌缺血再灌注损伤的保护作用

目的探讨重组人可溶性补体受体1型SCR15-18片段（sCR1-SCR15-18）对心肌缺血再灌注的保护作用。方法36只SD大鼠随机分为假手术（SO）组,缺血再灌注（I／R）组和sCR1-SCR15-18（sCR1）保护组。建立急性心肌缺血再灌注模型,结扎冠状动脉前立即注射磷酸盐缓冲液（0.1mL／100g）或sCR1-SCR15-18蛋白（15mg／kg）。测定心肌梗塞面积,血清中乳酸脱氢酶（LDH）和肌酸激酶（CK）,心肌组织髓过氧化物酶（MPO）活性,HE染色观察心肌病理改变和免疫组织化学法检测C3c。结果（1）心肌梗死面积：I／R组为（22．9±3．0）％,sCR1保护组为（16．1±3．3）％（P〈0．05）。（2）血清心肌酶CK（U／L）：I／R组为3400．9±534．9,sCR1保护组为2532．5±597．1（P〈0．05）。LDH（U／L）：I／R组为6572．0±476．3,sCR1保护组为5436．2±611．3（P〈0．05）。（3）心肌组织MPO活性（U／g）：I／R组为1．12±0．13,sCR1保护组为0．81±0．14（P〈0．05）。（4）心肌病理改变：I／R组心肌有断裂、坏死,间质肿胀,出血及中性粒细胞浸润,sCR1保护组心肌的以上病理变化明显较I／R组减轻。（5）与I／R组比sCR1保护组梗死区心肌组织C3c的沉积减少。结论sCR1-SCR15-18蛋白对大鼠急性心肌缺血再灌注损伤具有保护作用。     

Nuclear factor-kappaB decoy oligodeoxynucleotides attenuates ischemia/reperfusion injury in rat liver graft

AIM: To evaluate the protective effect of NF-kappaB decoy oligodeoxynucleotides (ODNs) on ischemia/reperfusion (I/R) injury in rat liver graft. METHODS: Orthotopic syngeneic rat liver transplantation was performed with 3 h of cold preservation of liver graft in University of Wisconsin solution containing phosphorothioated double-stranded NF-kappaB decoy ODNs or scrambled ODNs. NF-kappaB decoy ODNs or scrambled ODNs were injected intravenously into donor and recipient rats 6 and 1 h before operation, respectively. Recipients were killed 0 to 16 h after liver graft reperfusion. NF-kappaB activity in the liver graft was analyzed by electrophoretic mobility shift assay (EMSA). Hepatic mRNA expression of TNF-alpha, IFN-gamma and intercellular adhesion molecule-1 (ICAM-1) were determined by semiquantitative RT-PCR. Serum levels of TNF-alpha and IFN-gamma were measured by enzyme-linked immunosorbent assays (ELISA). Serum level of alanine transaminase (ALT) was measured using a diagnostic kit. Liver graft myeloperoxidase (MPO) content was assessed. RESULTS: NF-kappaB activation in liver graft was induced in a time-dependent manner, and NF-kappaB remained activated for 16 h after graft reperfusion. NF-kappaB activation in liver graft was significant at 2 to 8 h and slightly decreased at 16 h after graft reperfusion. Administration of NF-kappaB decoy ODNs significantly suppressed NF-kappaB activation as well as mRNA expression of TNF-alpha, IFN-gamma and ICAM-1 in the liver graft. The hepatic NF-kappaB DNA binding activity [presented as integral optical density (IOD) value] in the NF-kappaB decoy ODNs treatment group rat was significantly lower than that of the I/R group rat (2.16+/-0.78 vs 36.78+/-6.35 and 3.06+/-0.84 vs 47.62+/- 8.71 for IOD value after 4 and 8 h of reperfusion, respectively, P<0.001). The hepatic mRNA expression level of TNF-alpha, IFN-gamma and ICAM-1 [presented as percent of beta-actin mRNA (%)] in the NF-kappaB decoy ODNs treatment group rat was significantly lower than that of the I/R group rat (8.31+/-3.48 vs 46.37+/-10.65 and 7.46+/- 3.72 vs 74.82+/-12.25 for hepatic TNF-alpha mRNA, 5.58+/-2.16 vs 50.46+/-9.35 and 6.47+/-2.53 vs 69.72+/-13.41 for hepatic IFN-gamma mRNA, 6.79+/-2.83 vs 46.23+/-8.74 and 5.28+/-2.46 vs 67.44+/-10.12 for hepatic ICAM-1 mRNA expression after 4 and 8 h of reperfusion, respectively, P<0.001). Administration of NF-kappaB decoy ODNs almost completely abolished the increase of serum level of TNF-alpha and IFN-gamma induced by hepatic ischemia/reperfusion, the serum level (pg/mL) of TNF-alpha and IFN-gamma in the NF-kappaB decoy ODNs treatment group rat was significantly lower than that of the I/R group rat (42.7+/-13.6 vs 176.7+/-15.8 and 48.4+/-15.1 vs 216.8+/-17.6 for TNF-alpha level, 31.5+/-12.1 vs 102.1+/-14.5 and 40.2+/-13.5 vs 118.6+/-16.7 for IFN-gamma level after 4 and 8 h of reperfusion, respectively, P<0.001). Liver graft neutrophil recruitment indicated by MPO content and hepatocellular injury indicated by serum ALT level were significantly reduced by NF-kappaB decoy ODNs, the hepatic MPO content (A655) and serum ALT level (IU/L) in the NF-kappaB decoy ODNs treatment group rat was significantly lower than that of the I/R group rat (0.17+/-0.07 vs 1.12+/-0.25 and 0.46+/-0.17 vs 1.46+/-0.32 for hepatic MPO content, 71.7+/-33.2 vs 286.1+/-49.6 and 84.3+/-39.7 vs 467.8+/-62.3 for ALT level after 4 and 8 h of reperfusion, respectively, P<0.001). CONCLUSION: The data suggest that NF-kappaB decoy ODNs protects against I/R injury in liver graft by suppressing NF-kappaB activation and subsequent expression of proinflammatory mediators.     

Delayed ethyl pyruvate therapy attenuates experimental severe acute pancreatitis via reduced serum high mobility group box 1 levels in rats

AIM： To investigate the effect of delayed ethyl pyruvate （EP） delivery on distant organ injury, survival time and serum high mobility group box 1 （HMGB1） levels in rats with experimental severe acute pancreatitis （SAP）.
METHODS： A SAP model was induced by retrograde injection of artificial bile into the pancreatic ducts of rats. Animals were divided randomly into three groups （n = 32 in each group）： sham group, SAP group and delayed EP treatment group. The rats in the delayed EP treatment group received EP （30 mg/kg） at 12 h, 18 h and 30 h after induction of SAP. Animals were sacrificed, and samples were obtained at 24 h and 48 h after induction of SAP. Serum HMGB1, aspartate arninotransferase （AST）, alanine arninotransferase （ALT）, blood urea nitrogen （BUN）, and creatinine （Cr） levels were measured. Lung wet-to-dry-weight （W/D） ratios and histological scores were calculated to evaluate lung injury. Additional experiments were performed between SAP and delayed EP treatment groups to study the influence of EP on survival times of SAP rats.
RESULTS： Delayed EP treatment significantly reduced serum HMGB1 levels, and protected against liver, renal and lung injury with reduced lung W/D ratios （8.22 ±0.42 vs 9.76 ± 0.45, P 〈 0.01）, pulmonary histological scores （7.1 ± 0.7 vs 8.4 ± 1.1, P 〈 0.01）, serum AST （667 ± 103 vs 1 368 ± 271, P 〈 0.01）, ALT （446 ± 91 vs 653 ± 98, P 〈 0.01） and Cr （1.2 ± 0.3 vs 1.8 ± 0.3, P 〈 0.01） levels. SAP rats had a median survival time of 44 h. Delayed EP treatment significantly prolonged median survival time to 72 h （P 〈 0.01）.
CONCLUSION： Delayed EP therapy protects against distant organ injury and prolongs survival time via reduced serum HMGBllevels in rats with experimental SAP. EP may potentially serve as an effective new therapeutic option against the inflammatory response and multiple organ dysfunction syndrome （MODS） in SAP patients.     

血红素氧合酶-1对老龄脓毒症大鼠微循环及肝脏功能的影响

目的研究血红素氧合酶-1(HO-1)对老龄脓毒症大鼠微循环及肝脏功能的影响及其作用机制。方法采用盲肠结扎穿孔术(CLP)制备老龄脓毒症大鼠模型,72只老龄Wistar雄性大鼠按随机数字表法分为四组:假手术组(sham组)、脓毒症组(CLP组)、氯化血红素组(CLP+hemin组)及锌卟啉原组(CLP+znpp组),分时相检测各组丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、凝血酶原时间(PT)、活化部分凝血活酶时间(APTT),ELISA法检测血浆活化蛋白C(APC)、蛋白C(PC)、肿瘤坏死因子(TNF)-α水平变化;应用MSB(Martius-Scarlet-Blue)染色对比各组肝脏组织血栓形成情况;应用免疫荧光共聚焦显微镜比较各组大鼠肝脏PC表达情况;Western印迹检测肝脏组织HO-1、PC表达水平。结果与对照组相比,CLP组大鼠血浆APC、PC水平下降(P<0.05),TNF-α水平上升(P<0.05),PT、APTT缩短(P<0.05),肝脏微血栓形成增加(P<0.05),ALT、AST升高(P<0.05),肝脏PC表达下降(P<0.05),此变化在CLP+znpp组中更为明显;而与CLP组相比,CLP+hemin组大鼠血浆APC、PC水平上升(P<0.01),TNF-α水平下降(P<0.05),PT、APTT延长(P<0.05),肝脏微血栓明显减少(P<0.05),ALT、AST下降(P<0.01),肝脏PC表达上调(P<0.01)。结论 HO-1可以上调老龄脓毒症大鼠肝脏中PC表达,提高血浆中PC、APC水平,通过PC途径抑制老龄脓毒症大鼠肝脏微血栓形成,改善微循环障碍,保护肝脏功能。     

四氯化碳诱导大鼠肝纤维化脂质过氧化相关蛋白表达的动态变化及一贯煎的干预效应

目的 探讨四氯化碳(CCl4)诱导大鼠肝纤维化脂质过氧化相关蛋白表达的动态变化及一贯煎的干预效应.方法 Wistar雄性大鼠57只,其中模型组39只,正常组18只.模型大鼠腹腔注射50％的CCl4橄榄油溶液(1ml/lg),每周2次,共9周.造模3、6周后,随机抽取正常及模型大鼠各6只,处死作动态观察.其余模型大鼠随机分为模型组15只及干预组12只,模型组大鼠在8周时处死4只观察成模情况.第7周开始,继续造模的同时,干预组用一贯煎(2.682 g/kg)蒸馏水稀释灌胃,1次/d,共计3周.用药3周结束后,处死大鼠,检测肝功能、肝组织羟脯氨酸(Hyp)和丙二醛(MDA)含量、超氧化物歧化酶(SOD)与谷胱甘肽(GSH)活性,以及热休克蛋白70 (HSP70)、血红素加氧酶-1(HO-1)、转铁蛋白(Transferrin)、过氧化还原酶(Prxd)6、肝脏型脂肪酸结合蛋白(L-FABP)等的表达.计量资料采用单因素方差分析,计数资料采用Ridit分析. 结果 (1)与对照组比较,模型组大鼠6、9周时肝组织MDA含量显著升高[(4.23±0.45) nmol/mg比(2.22±0.59)nmol/mg; (6.29±1.23) nmol/mg比(2.22±0.59) nmol/mg,F值分别为60.13、66.99,P值均＜ 0.05];SOD活性显著降低[(196.94±39.20) U/mg比(264.50±30.44)U/mg,F=11.12,P＜ 0.05; (152.21±51.65) U/mg比(264.50±30.44) U/mg,F=23.11,P＜0.01];GSH含量显著降低[(48.47±7.27) nmol/mg比(60.74±9.04) nmol/mg,F=6.71,P＜0.05;(37.89±9.01) nmol/mg比(60.74±9.04)nmol/mg,F=24.06,P＜0.01];与9周模型组比较,干预组MDA显著降低[(4.25±0.86) nmol/mg比(6.29±1.23) nmol/mg,F=19.52,P＜ 0.01],SOD显著升高[(198.35±46.48) U/mg比(152.21±51.65) U/mg,F=4.65,P＜0.05],GSH显著升高[(53.73±7.54) nmol/mg比(37.89±9.01) nmol/mg,F=19.23,P＜0.01];(2)与正常组比较,9周时模型组大鼠HSP70蛋白表达量升高(1.21±0.06比0.58±0.07,F=166.87,P＜0.0l),HO-1蛋白表达量也升高(1.11±0.06比0.58±0.06,F=123.96,P＜ 0.01),Prdx6蛋白表达量降低(0.04±0.05比1.49±0.05,F=1215.85,P＜0.01),L-FABP表达量降低(0.24±0.02比1.44±0.14,F=219.05,P＜0.01),Transferrin蛋白表达量降低(0.67±0.03比1.67±0.04,F=301.35,P＜0.01).9周时,干预组HSP70和HO-1蛋白表达量分别为0.82±0.04、0.90±0.04,与9周时模型组比较,F值分别为92.31、26.89,P值均＜0.01,差异有统计学意义;9周时,干预组Prdx6、L-FABP和Transferrin蛋白表达分别为0.88±0.11、1.36±0.13、1.04±0.12,与9周时模型组比较,F值分别为150.17、237.19、27.53,P值均＜0.01,差异有统计学意义. 结论 一贯煎具有促进机体抗氧化物质生成、减轻脂质过氧化损伤的作用.     

Protection against hepatic ischemia/reperfusion injury via downregulation of toll-like receptor 2 expression by inhibition of Kupffer cell function

AIM: To elucidate the mechanism of liver protection by inhibition of Kupffer cells (KCs) function. METHODS: All the animals were randomly divided into three groups. Blockade group (gadolinium chloride solution (GdCl3) injection plus ischemia/reperfusion (I/R) injury): GdCl3 solution was injected once every 24 h for 2 d via the tail vein before I/R injury. Non-blockade group (saline solution injection plus I/R injury): saline instead of GdCl3 as a control was injected as in the blockade group. Sham group: saline was injected without I/R injury. Liver samples were collected 4 h after blood inflow restoration. The blockade of the function of KCs was verified by immunostaining with an anti-CD68 mAb. Toll-like receptor 2 (TLR2) was immunostained with a goat antimouse polyclonal anti-TLR2 antibody. Membrane proteins were extracted from the liver samples and TLR2 protein was analyzed by Western blot. Portal vein serum and plasma were taken respectively at the same time point for further detection of the levels of tumor necrosis factor-α (TNF-α) and alanine aminotransferase (ALT), an indicator of liver function. RESULTS: Compared to non-blockade group, CD68+ cells significantly reduced in blockade group (OPTDI, optical density integral): 32.97±10.55 vs 185.65±21.88, P<0.01) and the liver function impairment was relieved partially (level of ALT: 435.89±178.37 U/L vs 890.21±272.91 U/L, P<0.01).The expression of TLR2 protein in blockade group significantly decreased compared to that in non-blockade group (method of immunohistochemistry, OPDTI: 75.74±17.44 vs 170.58±25.14, P<0.01; method of Western blot, A value: 125.89±15.49 vs 433.91±35.53, P<0.01). The latter correlated with the variation of CD68 staining (r= 0.745, P<0.05). Also the level of portal vein TNF-a decreased in blockade group compared to that in non-blockade group (84.45±14.73 ng/L vs 112.32±17.56 ng/L, P<0.05), but was still higher than that in sham group (84.45±14.73 ng/L vs 6.07±5.33 ng/L, P<0.01). CONCLUSION: Inhibition of the function of KCs may protect liver against I/R injury via downregulation of the expression of TLR2.     

Intestinal endotoxemia plays a central role in development of hepatopulmonary syndrome in a cirrhotic rat model induced by multiple pathogenic factors

AIM： To characterize the correlation between severity of hepatopulmonary syndrome （HPS） and degree of hepatic dysfunction, and to explore how intestinal endotoxemia （IETM） affects the development of HPS in cirrhotic rats.
METHODS： Male Wister rats were fed with a diet containing maize flour, lard, cholesterol, and alcohol and injected subcutaneously with CCl4 oil solution every two days for 8 wk to induce typical cirrhosis and development of HPS. The animals were also given a nitric oxide （NO） production inhibitor, N^ω-nitro-L-arginine methyl ester （L-NAME） intraperitoneally, and an iNOS inhibitor, aminoguanidine hydrochloride （AG） via gavage daily from the end of the 4th wk to the end of the 6th or 8th wk, or a HO-1 inhibitor, zinc protoporphyrin （ZnPP） intraperitoneally 12 h prior to killing. Blood, liver and lung tissues were sampled.
RESULTS： Histological deterioration of the lung paralleled to that of the liver in the cirrhotic rats. The number of pulmonary capillaries was progressively increased from 6.1 ± 1.1 （count/filed） at the 4th wk to 14.5 ± 2.4 （count/filed） at the 8th wk in the cirrhotic rats. Increased pulmonary capillaries were associated with increased blood levels of lipopolysaccharide （LPS） （0.31 ± 0.08 EU/mL vs control 0.09 ± 0.03 EU/mL）, alanine transferase （ALT, 219.1 ± 17.4 U/L vs control 5.9 ± 2.2 U/L） and portal vein pressure. Compared with normal control animals, the number of total cells in bronchoalveolar lavage fluid （BALF） of the cirrhotic rats at the 8th wk was not changed, but the number of macrophages and the ratio of macrophages to total cells were increased by nearly 2-fold, protein expression of inducible nitric oxide synthase （iNOS） and endothelial nitric oxide synthase （eNOS） started to increase significantly at the 4th wk, and reached its peak at the 8th wk in the lung of cirrhotic rats. The increase of iNOS expression appeared to be quicker than that of eNOS. NO2^-/NO3^- was also increased, which was cor