The effect of aminoguanidine on blood and tissue lipid peroxidation in jaundiced rats with endotoxemia induced with LPS.

Obstructive jaundice (OJ) is a severe condition that leads to several complications. One of the important problems in OJ is the increased incidence of endotoxemia, which is the result of bacterial translocation (BT) and defective host immune response. Lipid peroxidation (LP) is an important problem in OJ and sepsis in which nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) activity are increased and antioxidative activity is decreased. Formation of peroxynitrite (ONOO(-)) anion leads to cellular damage and apoptosis. In this experimental study, we explore the effect of specific iNOS inhibitor aminoguanidine (AG) on blood and tissue (liver and renal) LP and iNOS levels in jaundiced rats with endotoxemia induced with lipopolysaccharide (LPS). Rats were randomized into six groups; group A, sham; group B, obstructive jaundice (OJ); group C, OJ + LPS; group D, OJ + AG; group E, OJ + LPS + AG; group F, OJ + AG + LPS. Serum malondialdehyde (MDA) and serum myeloperoxidase (MPO) activity and liver and renal tissue MDA, MPO, and Na(+)/K(+)-ATPase activity levels were detected in biochemical methods. Liver and renal tissue iNOS levels were examined immunohistopathologically. Serum and tissue MDA and MPO levels and tissue iNOS expression were increased significantly in groups B, C, and E, while tissue ATPase levels were decreased significantly in the same groups. In the group treated with AG (group D), serum and tissue MDA and MPO levels and tissue iNOS expression were decreased while tissue ATPase levels were increased significantly. In group F, if AG was administrated before LPS, we observed that serum and tissue MDA and MPO levels and tissue iNOS expression were decreased while tissue ATPase levels were increased significantly. Thus, our study showed that AG had a protective effect when it was administrated before LPS, but it failed to prevent tissue iNOS expression and LP if there was established endotoxemia in OJ.     

Effect of N-acetylcysteine on blood and tissue lipid peroxidation in lipopolysaccharide-induced obstructive jaundice.

In obstructive jaundice, free radical production is increased and antioxidative activity is reduced. N-Acetylcysteine (NAC) has a beneficial effect with anti-inflammatory and antioxidant activity, acting as a free radical scavenger. NAC inhibits inducible nitric oxide synthase, suppresses cytokine expression/release, and inhibits adhesion molecule expression and nuclear factor kappa B. The aim of this study was to investigate the effects of NAC on liver/renal tissue and serum lipid peroxidation in lipopolysaccharide (LPS)-induced obstructive jaundice. We randomized 60 rats into 6 groups: group 1, Sham; group 2, obstructive jaundice (OJ) induced after bile-duct ligation; group 3, OJ + NAC (100 mg kg- 1 subcutaneously); group 4, OJ + LPS (10 mg kg-1); group 5, OJ + NAC + LPS; and group 6, OJ + LPS + NAC. For each group, the biochemical markers of lipid peroxidation and the antioxidant products were measured in serum and liver/renal tissue after sacrifice. Almost all lipid peroxidation products levels were increased and antioxidant products levels were decreased in groups who received LPS (groups 4, 5, and 6), but the effect was less remarkable when NAC was administered before LPS (group 5). The same trend was seen for groups with OJ +/- LPS who did not received NAC or received it after induced toxemia (groups 2, 4, and 6) as compared to groups 1 and 3. Moreover, in the case of OJ + LPS, rats treated with NAC before LPS (group 5) had lower lipid peroxidation products levels and higher antioxidant products levels as compared to those who did not received NAC (group 4). This phenomenon was not reproducible with NAC administered after LPS (group 6). Thus, results of this study showed that NAC prevents the deleterious effects of LPS in obstructive jaundice by reducing lipid peroxidation in serum and liver/renal tissue if administered before LPS. Nonetheless, NAC failed to prevent the lipid peroxidation in the case of established endotoxemia in obstructive jaundice.     

The effect of N-acetylcysteine on pulmonary lipid peroxidation and tissue damage

BACKGROUND: We aimed to investigate the effect of N-acetylcysteine (NAC) on pulmonary lipid peroxidation and tissue damage in experimental obstructive jaundice (OJ) stimulated by lipopolysaccharide (LPS) in this study. MATERIALS AND METHODS: We randomized 40 rats into five groups. Group A: Sham (n = 8); group B: OJ (n = 8); group C: OJ + lipopolysaccharide (LPS; n = 8); group D: OJ + NAC + LPS (n = 8); group E: OJ + LPS + NAC (n = 8). OJ was performed by common bile duct ligation and division in all groups except the sham group. At the fifth day, the rats were jaundiced. At the fifth day of OJ, LPS was injected 10 mg/kg intraperitoneally to the rats and at the tenth day, the rats were sacrificed in group C. In group D; at the fifth day of OJ, NAC was started 100 mg/kg subcutaneously and the same dose NAC injection repeated every day for 5 days. At the tenth day of OJ, LPS was injected 10 mg/kg intraperitoneally to the rats and then after 6 h they were sacrificed. In group E; 10 mg/kg LPS was administered intraperitoneally at fifth day of OJ and after then NAC was started 100 mg/kg subcutaneously and the same dose NAC injection repeated every day for 5 days and at the tenth day, the rats were sacrificed. Tissue samples were harvested through a midline incision, and lungs were resected and examined histopathologically and immunohistochemically for tissue damage scoring. The blood was taken by cardiac puncture and malondialdehyde (MDA), myeloperoxidase (MPO), and levels of total antioxidant status were detected with biochemical methods to evaluate lung tissue damage. RESULTS: Increase in lung and serum MDA and MPO levels, as well as decrease in total antioxidant status, were observed in groups B and C when compared with the sham group (P = 0.0001, for each comparison). Furthermore, the lung tissue damage was observed in the same groups by histopathological examination when compared with sham group. There was significant decrease at serum and lung MPO and MDA levels after the NAC application in groups D and E, when compared with group C (P = 0.0001, for each comparison). Antioxidant status in groups D and E were increased in the presence of NAC (P = 0.0001, for each comparison). Lung histology was prevented relatively in group D when compared with groups B and C. CONCLUSION: Results of the study indicate that NAC has protective effect on pulmonary lipid peroxidation and tissue damage before and after LPS administration.     

促红细胞生成素预先给药对大鼠内毒素性急性肺损伤的影响

目的 探讨促红细胞生成素(EPO)预先给药对大鼠内毒素性急性肺损伤的影响.方法 成年雄性SD大鼠32只,体重180～220 g,随机分为4组(n=8),C组腹腔注射生理盐水4 ml/kg(EPO溶剂对照),30 min后静脉注射生理盐水2 ml/kg[脂多糖(LP3)溶剂对照];EPO组腹腔注射EPO3 000 U/kg,30 min后静脉注射生理盐水2 ml/kg;LPS组腹腔注射生理盐水4 ml/kg,30 min后静脉注射LPS 6 mg/kg;EPO+LPS组腹腔注射EPO 3 000 U/kg,30 min后静脉注射LPS 6 mg/kg.于静脉注射LPS后4 h时处死大鼠,观察肺组织病理学结果 ,计算肺组织湿/干重(W/D)比;测定肺组织髓过氧化物酶(MPO)活性和丙二醛(MDA)、一氧化氮(NO)含量;采用Western blot法测定肺组织诱导型一氧化氮合酶(iNOS)和硝基酪氨酸(NT)的表达.结果 与C组相比,LPS组和EPO+LPs组肺组织W/D比、MPO活性、MDA和NO含量升高,iNOS和NT表达上调(P<0.01);与LPS组相比,EPO+LPS组肺组织W/D比、MPO活性、MDA和NO含量降低,iNOS和NT表达下调(P<0.01).结论 EPO预先给药可减轻大鼠内毒素性急性肺损伤,与其下调iNOS表达,减少NO生成有关.     

青藤碱对梗阻性黄疸大鼠急性肾损伤的保护作用

目的：探讨青藤碱对梗阻性黄疸（OJ）大鼠急性肾损伤的保护作用及机制。 方法：将24只大鼠随机分均为假手术组、模型组与青藤碱干预组,后两组大鼠行胆总管结扎切断制作OJ模型。青藤碱干预组大鼠于术后第1天起给予青藤碱（80 mg/kg）灌胃,每天1次,而假手术组与模型组大鼠以同样方式给予等量生理盐水代替。术后第8天处死各组大鼠,取血检测血清尿素氮（SUN）、血清肌酐（Scr）含量,取肾组织行病理学检查,检测肾组织丙二醛（MDA）、髓过氧化物酶（MPO）水平和总抗氧化能力（T-AOC）以及转化生长因子（TGF-β1）蛋白与mRNA的表达。 结果：除假手术组外,其余两组大鼠术后均出现OJ表现以及明显的肾损伤病理学改变,但青藤碱干预组的肾损伤轻于模型组。与假手术组比较,其余两组大鼠SUN、Scr水平均明显升高;肾组织MDA、MPO含量、TGF-β1蛋白和mRNA表达明显升高,T-AOC明显降低（均P<0.05）,但青藤碱干预组以上指标的改变程度均明显低于模型组（均P<0.05）。 结论：青藤碱对OJ大鼠急性肾损伤具有保护作用,其机制可能与其抗氧化作用以及抑制TGF-β1的表达有关。

     

The protective effects of early treatment with propofol on endotoxin-induced acute lung injury in rats

To investigate the effects of treatment with propofol administration at different time point in acute lung injury of endotoxin-induced shock rats. METHODS: 76 male wistar rats were randomly assigned to five groups: A) control group; B) endotoxemic group, receiving intravenous lipopolysaccharide (LPS) 8 mg.kg-1; C) pretreatment group, treated identically to endotoxemic group with the additional administration of propofol (5 mg.kg-1 bolus, followed by infusion at 10 mg.kg-1.h-1) of 1 hr prior to the injection of LPS; D) simultaneously treatment group, treated identically to endotoxemic group with the additional administration of propofol simultaneously with the injection of LPS; E) post-treatment group, which was treated identically to endotoxemic group except for administration of propofol 1 hr after the injection of LPS. PaO2, pH, MAP and survival rate were recorded and plasma NO, TNF-alpha were measured during 5-hr after the injection of LPS. After the rats were killed, lung tissue was sampled to measured expression of inducible nitric oxide synthase (iNOS), nitrotyrosine (NT), myeloperoxidase (MPO) activity, malondialdehyde (MDA), wet-to-dry lung weight ratio (W/D), and pulmonary permeability index (PPI). RESULTS: Compared with the endotoxemic group, both the pretreatment and simultaneously treatment groups, significantly improved PaO2, pH, MAP and 5th hour survival rate of rats, and attenuated endotoxin-induced increased iNOSmRNA, NT expression, MPO activity and MDA level in lung tissue, and decreased pulmonary microvascular permeability, TNF-alpha, NO in plasma. But these beneficial efficacies were blunted in the post-treatment group. CONCLUSIONS: These findings showed that propofol administration may provide protective effects on acute lung injury in endotoxin-induced shock.     

NF-κB信号通路在异丙酚抑制脂多糖诱导RAW264.7细胞诱导型一氧化氮合酶基因表达上调中的作用

目的 探讨NF-κB信号通路在异丙酚抑制脂多糖(LPS)诱导RAW264.7细胞诱导型一氧化氮合酶( iNOS)基因表达上调中的作用.方法 体外培养RAW264.7细胞,以5×105/ml密度接种于6 cm培养皿(3 ml/皿)或6孔板(2 ml/孔),采用随机数字表法,将其随机分为3组(n=18):正常对照组(C组)、LPS组(L组)和LPS+异丙酚(LP组).C组不做任何处理;L组和LP组均加入1μg/mlLPS,LP组于加入LPS前2h加入50 μmol/L异丙酚.于LPS孵育30 min时,每组取6皿和6孔,收集细胞,分别采用免疫印迹法测定磷酸化IκB激酶(p-IKK)和NF-κB活性;于LPS孵育6h时,每组取6皿,收集细胞,测定iNOS mRNA表达.结果 与C组比较,L组p-IKK和iNOS mRNA表达上调,NF-κB活性升高(P＜0.05);与L组比较,LP组p-IKK和iNOS mRNA表达下调,NF-κB活性降低(P＜0.05).结论 NF-κB信号通路参与了异丙酚抑制脂多糖诱导的RAW264.7细胞iNOS基因表达上调.     

Effective inhibition of nitric oxide production by aminoguanidine does not reverse hypotension in endotoxaemic rats

BACKGROUND: Excess production of nitric oxide (NO) by the inducible NO synthase (iNOS) has been implicated in the pathophysiology of septic shock. Using methaemoglobin (metHb) and the stable NO metabolite nitrate as markers of NO formation, we assessed the effect of iNOS blockade by aminoguanidine (AG) on hypotension and NO formation in endotoxaemic rats. METHODS: In 32 male Wistar rats under chloralose anaesthesia, MetHb (at 15 and 330 min, respectively) and plasma nitrate (at 330 min) were determined. Mean arterial pressure, heart rate and haematocrit were monitored. The LPS group (n=8) received bacterial endotoxin (LPS), 3 mg kg(-1) i.v. and was subsequently monitored for 5 h. At 2 h after LPS, the LPS+AG20 group (n=8) received AG, 5 mg kg(-1), and 5 mg kg(-1) h(-1) for the remaining 3 h. The LPS+AG100 group (n=8) instead received 25 mg kg(-1), followed by 25 mg kg(-1) h(-1). The NaCl group (n=8) was given corresponding volumes of isotonic saline. RESULTS: AG decreased the LPS-induced rise in plasma nitrate by about 50% in the LPS+AG20 group. MetHb levels, however, were not appreciably reduced by this dose. Both NO metabolites reached control levels after the higher dose of AG. LPS caused a progressive decrease in haematocrit. AG did not influence the LPS-induced hypotension, tachycardia or haemodilution. CONCLUSION: AG inhibited NO formation in a dose-dependent way. Yet, AG had no haemodynamic effects, suggesting a minor cardiovascular influence of iNOS in this endotoxin model, in parallel to what has been found in microbial sepsis.     

Evaluation of Gadolinium Pre-Treatment with or without Splenectomy in the Setting of Renal Ischemia Reperfusion Injury in Rats

Introduction.?This study aims to investigate gadolinium chloride (Gd) pre-treatment with/without splenectomy (Splx) in the setting of renal ischemia/reperfusion (IR) injury in rats. Materials and Methods.?Under anesthesia, male Wistar albino rats with or without splenectomized (Splx) were right nephrectomized and subjected to 45 min of renal pedicle occlusion followed by 3 h of reperfusion. Gadolinium chloride (10 mg kg^?1) or saline was administered 24 hours prior to ischemia via penile vein. Right nephrectomy and intravenous saline administration was performed in the control group. At the end of the reperfusion period, following decapitation, kidney samples were taken for histological examination or determination of renal malondialdehyde (MDA) and glutathione (GSH) levels and myeloperoxidase (MPO) and Na⁺-K⁺ ATPase activities. Creatinine, blood urea nitrogen (BUN), lactate dehydrogenase (LDH), TNF-α, and IL-1β were assayed in the serum samples. Results.?Ischemia/reperfusion caused significant increases in the serum TNF-α, IL-1β, BUN, creatinine, AST, ALT, LDH, and tissue MDA levels and MPO activity, while either Gd pre-treatment or Splx decreased these parameters significantly. On the other hand, IR induced a decrease in the tissue GSH, and Na⁺-K⁺ ATPase activity was restored by both gadolinium and Splx. Furthermore, histopathological alterations induced by IR were also reversed.?Conclusion.?The extent of renal IR injury depends on the pro-inflammatory cytokine response. Gd pre-treatment decreases macrophage-derived cytokine secretion and thereby effectively limits the extent of renal IR injury in rats similar to Splx. Further studies needed to define an optimal way of decreasing macrophage-derived cytokine release due to the clinical limitations of Gd.     

The Role of Oxygen Free Radicals in Acute Renal Failure Complicating Obstructive Jaundice: An Experimental Study

Oxydant injury is considered to be an important mechanism in the pathophysiology of acute renal failure. It has been thought that decrease in extracellular and intracellular fluid and endotoxemia seen in obstructive jaundice may cause an increase in production of oxygen free radicals and impairment in antioxydant defense mechanism. This study is designed to investigate the possible role of oxydant injury in renal failure seen in jaundiced patients. In this study, 28 rats were divided into four groups: Control(C) (N=7); Renal ischemia (RI) (N=7); Obstructive jaundice+renal ischemia (OJ+RI) (N=7); Obstructive jaundice (OJ) (N=7). All groups were compared with each other according to renal failure findings and enzyme activities, such as Xanthine oxidase (XOD), Superoxide Dismutase (SOD) and Catalase in renal cortex and Glutathione Peroxidase (GSH-Px), in blood at 3rd day after ischemia and reperfusion. Renal failure findings monitored by blood urea and creatinine levels, seemed more evident in OJ+RI than RI group (p <0.05). When compared with RI, in OJ+RI group, increase in XOD activity at 3rd day was statistically significant [0.259 ±0.01 U/g (tissue) and 0.362±0.03 U/g (tissue) respectively] (p <0.05). SOD and GSH-Px activities of each ischemic group at 3rd day were decreased compared to non-ischemic groups. This fall was significant (p <0.05). But there was no statistical difference between jaundiced and non-jaundiced groups. Alterations in catalase activities also had no statistical significance.These findings may suggest that the injury induced by oxygen free radicals at re-oxygenation of tissue after ischemia may also play a role in the pathogenesis of acute renal failure developed in obstructive jaundice.     

诱导性一氧化氮合酶在大鼠肝缺血再灌注损伤中的作用

目的 探讨诱导性一氧化氮合酶（iNOS）在大鼠部分肝缺血再灌注损伤中的作用.方法 选取雄性Sprague-Dawley大鼠30只,体重225～250 g,随机分成氨基胍（AG）组、脂多糖（LPS）组、对照组.每组均按相同方法建立70%的肝缺血再灌注损伤模型（缺血1 h,再灌注6 h）,取再灌注大鼠肝组织及血清样本.氨基胍（AG）组（n=10）：术前30 min尾静脉注射AG 100 mg/kg（质量浓度10 kg/L）;脂多糖（LPS）组（n=10）：术前30 min尾静脉注射LPS 10 mg/kg（质量浓度1 kg/L）;对照组（n=10）：术前30 min尾静脉注射生理盐水（10 μL/kg）.检测血清谷氨酸转氨酶（ALT）水平,实时荧光定量PCR测定肝组织iNOS mRNA的表达,Western blot测定肝组织iNOS蛋白的表达,考马斯法测定肝组织匀浆丙二醛（MDA）含量、超氧化物歧化酶（SOD）活性,HE染色光镜下组织学观察等.结果 AG组与对照组相比,肝组织中iNOS mRNA表达量明显下降（P〈0.05）,iNOS蛋白表达量明显下降（P〈0.05）;ALT和MDA明显下降（P〈0.05）;SOD明显升高（P〈0.05）;肝细胞水肿较轻,排列相对整齐.LPS组与对照组相比,肝组织中iNOS mRNA表达量明显升高（P〈0.05）,iNOS蛋白表达量明显升高（P〈0.01）;ALT和MDA明显升高（P〈0.05）;SOD则明显降低（P〈0.05）;肝细胞水肿,排列紊乱,并且出现水样变性.结论 iNOS 升高会加重缺血再灌注损伤,这一过程可能通过改变氧化还原状态实现.     

氨基胍对内毒素休克大鼠肝损伤的保护作用研究

目的 探讨诱导型一氧化氮合酶(iNOS)抑制剂氨基胍对内毒素休克大鼠肝脏的组织学和超微结构的影响。方法 取雄性wistar大鼠24只．随机分为正常对照组、内毒素对照组和氨基胍治疗组．每组各8只。用大肠杆菌内毒素(LPS)复制大鼠内毒素性休克模型．氨基胍治疗组采用氨基胍治疗。观察并比较三组大鼠肝脏的组织学、超微结构及其血浆一氧化氮(NO)含量的变化。结果 光镜下可见．内毒素组肝组织有散在小脓肿灶形成．肝细胞坏死，中性白细胞浸润．而氨基胍治疗组的肝组织受损程度较轻。电镜下可见，内毒素组的肝细胞核出现融解性空斑．线粒体肿胀和线粒体嵴数量减少．而氨基胍则对肝脏的结构起到一定的保护作用。内毒素对照组血浆NO水平明显高于正常对照组．给予氨基胍治疗后血浆NO水平明显下降．但仍高于正常对照组。结论 氨基胍通过选择性抑制iNOS活性．抑制了大鼠内毒素休克时过量的NO的产生．保护了肝脏的功能．具有潜在的临床应用价值．值得更深入地研究。     

一氧化氮在阻塞性黄疸病人肝脏损害中的作用

目的　探讨一氧化氮 (NO)在阻塞性黄疸病人肝脏损害中的作用。方法　选取 30例阻塞性黄疸 (OJ)病人和 30例对照 ,采用免疫组化方法检测肝脏组织诱生型一氧化氮合酶 (iNOS)的表达 ,用硝酸还原酶法测定外周血和胆汁中一氧化氮水平 ,用放射免疫法检测肿瘤坏死因子 (TNF) ,计算机图像分析仪对肝脏组织坏死面积进行检测。结果　 (1)OJ组外周血NO、GPT、TBil、TNF和胆汁中NO水平较对照组显著增高 (P <0 0 1) ;(2 )iNOS在 86 7%的OJ肝脏组织中阳性表达 ,在对照组肝脏组织中不表达 ;(3)肝脏组织坏死面积与iNOS表达强度及NO水平呈显著正相关 (P <0 0 1)。结论　NO参与了阻塞性黄疸病人肝脏损害的过程并起重要作用。     

盐酸戊乙奎醚对内毒素血症大鼠全身炎性反应的影响

目的 探讨盐酸戊乙奎醚对内毒素血症大鼠血清TNF-α、诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS),肺组织NF-κB亚基p65亲和肽(NF-κB p65)含量的影响. 方法 健康SD大鼠60只,采用随机数字表法分为5组(每组12只):对照组(C组)、内毒素组(LPS组)、LPS+低剂量盐酸戊乙奎醚组(P1组)、LPS+中剂量盐酸戊乙奎醚组(P2组)、LPS+高剂量盐酸戊乙奎醚组(P3组).LPS组腹腔注射内毒素8 mg/kg制备内毒素血症模型,C组给予等量生理盐水,P1组～P3组给予相应剂量的盐酸戊乙奎醚5 min后注射LPS,给药6h后处死动物取标本.采用ELISA检测血清TNF-α含量,采用比色法测血清iNOS活力,Western blot检测肺组织NF-κB p65含量,并观察肺组织病理学改变. 结果 与C组比较,LPS组、P1组、P2组、P3组血清TNF-α含量显著升高(P＜0.05),iNOS活力水平明显升高(P＜0.05),肺组织NF-κB p65表达明显增高(P＜0.05);与LPS组比较,P2组、P3组血清TNF-α、iNOS活力水平和肺组织NF-κB p65含量均下降(P＜0.05),而P1组TNF-α、iNOS活力和NF-κB p65表达水平,差异无统计学意义(P＞0.05);P2组、P3组间各指标表达水平比较,差异无统计学意义(P＞0.05);P2组、P3组肺组织病理学损伤程度明显轻于LPS组(P＜0.05). 结论 盐酸戊乙奎醚可能通过下调TNF-α、NF-κB p65的表达,减少iNOS活化来抑制内毒素休克大鼠全身炎症反应.     

L-精氨酸对内毒素诱导大鼠肺组织线粒体损伤的影响

目的 评价L精氨酸(L-Arg)对内毒素(LPS)诱导大鼠肺组织线粒体损伤的影响,探讨其减轻内毒素性急性肺损伤的作用机制.方法 雄性SD大鼠24只,随机分为3组(n=8):假手术组(S组)、LPS组和L-Arg组.LPS组和L-Arg组静脉注射LPS 5 mg/kg(用生理盐水稀释至1 ml/kg),S组给予生理盐水1 ml/kg,3 h后L-Arg组腹腔注射L-Arg 500 mg/kg(用生理盐水稀释至1 ml/kg),S组和Au组给予生理盐水1 ml/kg.注射L-Arg或生理盐水后3 h.取肺组织.提取线粒体,测定超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、ATPase、丙二醛(MDA)、一氧化氮合酶(NOS)、诱生型一氧化氮合酶(iNOS)、结构型一氧化氮合酶(cNOS)、一氧化氮(NO)的水平、线粒体膜肿胀度、线粒体活力和线粒体膜流动性;电镜观察肺组织超微结构.结果 与S组比较,LPS组SOD、GSH-Px、ATPase、线粒体活力和线粒体膜流动性降低,MDA、NOS、iNOS、NO及线粒体膜肿胀度升高(P<0.01);与LPs组比较,L-Arg组SOD、GSH.Px、ATPase、线粒体活力和线粒体膜流动性升高,MDA含量和线粒体膜肿胀度降低(P<0.05).L-Ars组细胞肿胀、线粒体肿胀和空泡化的程度轻于LPS组.结论 L-Arg可减轻LPS诱导大鼠肺组织线粒体损伤,其机制与增强抗过氧化能力有关.     

Exogenous normal lymph alleviates lipopolysaccharide-induced acute kidney injury in rats

Abstract

Background: Acute kidney injury (AKI) is a common pathological process which occurs in hemorrhage, intoxication, etc. It has been shown that the lymphatic circulation plays an important regulatory role in the pathogenesis of hemorrhage shock, and that exogenous normal lymph (ENL) has a beneficial effect on multiple organ injuries. In the present study, we investigated the effect of ENL on lipopolysaccharide (LPS)-induced AKI in rats. Methods: The AKI was induced by the jugular vein injection of LPS (iv, 15?mg/kg). After 15?min of LPS injection, saline or ENL without cell components (5?mL/kg) was iv infused at the speed of 0.5?mL per minute. Then, the renal function indices in plasma and renal histomorphology, and the levels of P-selectin, intercellular adhesion molecule-1 (ICAM-1), myeloperoxidase (MPO) and Na⁺-K⁺-ATPase in renal tissue were assessed at 3 or 6?h after LPS injection. Results: LPS induced a severe kidney injury including increased levels of urea, creatinine in plasma, aggrandized activities of ICAM-1 and MPO in renal tissue, and decreased the Na⁺-K⁺-ATPase activity in renal cells. These deleterious effects of LPS were significantly ameliorated by ENL treatment. Conclusion: The present results indicate that ENL protect against LPS-induced AKI, suggesting an alternative therapeutic strategy for treatment of kidney injury accompanied with severe infection or sepsis.     

内毒素血症时肺动脉和胸主动脉内一氧化氮合酶表达的比较

目的 观察内毒素血症时肺动脉和胸主动脉中诱导型一氧化氮合(iNOS)基因和蛋白表达的时间依从性变化。方法 48只Wistar大鼠350－450g，雌雄兼备，随机均分成对照组（C组），3h组，8h组和48h组。对照组腹腔内注射2ml生理盐水，余各实验组腹腔内注射脂多糖（LPS）4mg/kg，溶于2ml生理盐水，分别在LPS腹腔内注射后3h,8h和48h颈椎脱臼法处死大鼠取肺动脉和胸主动脉，RT－PR和Western blot法测定各组肺动脉和胸主动脉中iNOS的mRNA和蛋白表达。结果 LPS注射后大鼠肺动脉中iNOS的mRNA和蛋白表达逐渐上升，8h达到高峰，48h恢复到LPS注射前水平；胸主动脉中iNOS的蛋白表达3h即达峰值，以后逐渐下降，48h恢复到LPS注射前水平。LPS注射后3h和8h大鼠iNOS的mRNA及蛋白表达水平肺动脉比胸主动脉高。结论 内毒素大鼠的肺动脉和胸主动脉中iNOS的mRNA和蛋白的表达呈现时间依从性变化，iNOS的mRNA和蛋白表达峰值胸主动脉早于肺动脉，肺动脉中iNOS的mRNA和蛋白表达程度高于胸主动脉。     

intermedin对大鼠肾脏缺血再灌注损伤的保护作用及其机制

目的 观察intermedin（IMD）对大鼠肾脏缺血再灌注损伤（IRI）的保护作用并探讨其机制。 方法 健康雄性Wistar大鼠24只随机分为对照组、IRI组、转空质粒组、转IMD质粒组。动物右肾切除后,用超声微泡技术将质粒转染入肾脏,1周后制作肾脏IRI模型。PAS染色观察肾脏病理损伤,比色法检测肾组织超氧化物岐化酶（SOD）、髓过氧化物酶（MPO）和天冬氨酸半胱氨酸蛋白酶3（caspase-3）,以及脂质过氧化物丙二醛（MDA）含量。免疫组织化学方法检测细胞间黏附分子1（ICAM-1）、P选择素及内皮素1（ET-1）表达。TUNEL染色检测肾组织细胞凋亡。 结果 PAS染色结果显示,IRI组肾小管及间质病理损伤显著重于对照组（P < 0.01）;转IMD组肾组织病理损伤则显著轻于IRI组（P < 0.01）。IRI组肾组织SOD活性显著低于对照组（P < 0.05）,MPO活性、活性caspase-3、MDA含量及ICAM-1、P选择素和 ET-1表达均显著高于对照组（均P < 0.01）;转IMD组SOD活性显著高于IRI组（P < 0.05）,MPO活性、活性caspase-3、MDA含量及ICAM-1、P选择素和ET-1表达均显著低于IRI组（均P < 0.01）。TUNEL染色显示,IRI组肾组织凋亡细胞数显著高于对照组（34.83%±8.75%比3.33%±0.47%,P < 0.01）;转IMD组肾组织凋亡细胞数（20.67%±7.71%）则较IRI组显著减轻（P < 0.01）。转空质粒组和IRI组以上指标差异均无统计学意义。 结论 IMD能减轻肾脏IRI,其机制至少部分与抑制氧自由基生成、炎细胞浸润及炎性因子ICAM-1、P选择素生成、ET-1生成、细胞凋亡有关,从而减轻肾组织局部氧化应激反应产生的活性氧。