大蒜素对全脑缺血再灌注大鼠脑保护机制的研究

目的：通过大蒜素预处理,观察全脑缺血再灌注大鼠海马区ICAM-1 的表达,从而探讨大蒜素的脑保护机制。方法：雄性 Wistar 大鼠30 只,随机分为5 组：假手术组、缺血再灌注组、缺血再灌注+ 大蒜素10、20、30 mg/kg 组。采用四血管闭塞法制备大 鼠全脑缺血再灌注模型,于再灌注24 h 取出海马,硫堇染色观察海马组织的形态学改变,免疫组织化学染色测定海马CA1 区 ICAM-1 免疫反应阳性细胞面积和积分光密度值。结果：通过给予大鼠全脑缺血8 min 再灌注24 h处理,海马CA1 区组织形态学 改变显著,神经元密度明显降低;ICAM-1的表达显著增加。静脉给予大蒜素可使缺血再灌注海马组织形态学改变明显改善,存活 神经元数目增加,ICAM-1 表达显著较少。结论：大蒜素可以通过减少ICAM-1 的表达抑制全脑缺血再灌注后的炎症损失从而发 挥脑保护作用。     

Leukocyte and endothelial cell adhesion molecules in a chronic murine model of myocardial reperfusion injury

Expression of endothelial and leukocyte cell adhesion molecules is a principal determinant of polymorphonuclear neutrophil (PMN) recruitment during inflammation. It has been demonstrated that pharmacological inhibition of these molecules can attenuate PMN influx and subsequent tissue injury. We determined the temporal expression of alpha-granule membrane protein-40 (P-selectin), endothelial leukocyte adhesion molecule 1 (E-selectin), and intercellular cell adhesion molecule 1 (ICAM-1) after coronary artery occlusion and up to 3 days of reperfusion. The expression of all of these cell adhesion molecules peaked around 24 h of reperfusion. We determined the extent to which these molecules contribute to PMN infiltration by utilizing mice deficient (-/-) in P-selectin, E-selectin, ICAM-1, and CD18. Each group underwent 30 min of in vivo, regional, left anterior descending (LAD) coronary artery ischemia and 24 h of reperfusion. PMN accumulation in the ischemic-reperfused (I/R) zone was assessed using histological techniques. Deficiencies of P-selectin, E-selectin, ICAM-1, or CD18 resulted in significant (P < 0.05) attenuation of PMN infiltration into the I/R myocardium (MI/R). In addition, P-selectin, E-selectin, ICAM-1, and CD18 -/- mice exhibited significantly (P < 0.05) smaller areas of necrosis after MI/R compared with wild-type mice. These data demonstrate that MI/R induces coronary vascular expression of P-selectin, E-selectin, and ICAM-1 in mice. Furthermore, genetic deficiency of P-selectin, E-selectin, ICAM-1, or CD18 attenuates PMN sequestration and myocardial injury after in vivo MI/R. We conclude that P-selectin, E-selectin, ICAM-1, and CD18 are involved in the pathogenesis of MI/R injury in mice.     

Anti-shock effects of human superoxide dismutase in splanchnic artery occlusion (SAO) shock

We studied the effects of human superoxide dismutase (h-SOD) in splanchnic artery occlusion (SAO) shock. Pentobarbital anesthetized rats subjected to total occlusion of the superior mesenteric and the celiac arteries for 40 min developed a severe shock state usually resulting in a fatal outcome within 20 min after the release of the occlusion. h-SOD (10 mg/kg) was infused intravenously starting at reperfusion and lasting for 10 min. SAO shock rats treated with h-SOD maintained postreperfusion MABP at significantly higher values compared to rats receiving the vehicle (final MABP 84 +/- 6 vs 46 +/- 1 mm Hg, P less than 0.01, respectively). Treatment with h-SOD attenuated the plasma accumulation of free amino-nitrogen compounds (P less than 0.01 from vehicle) as well as the activity of the lysosomal protease cathepsin D (P less than 0.05 from vehicle). Furthermore, the plasma activity of a myocardial depressant factor was significantly lower in h-SOD-treated rats than in SAO rats receiving only the vehicle (27 +/- 1 vs 64 +/- 3 U/ml, P less than 0.01). SAO shock rats treated with h-SOD also exhibited a significantly higher survival rate than the SAO shock +/- vehicle group (88% vs 11%, P less than 0.01, respectively). These results support the role of oxygen-derived radicals in the pathophysiology of SAO shock, and indicate that h-SOD effectively ameliorates the deleterious effects of oxygen radicals in this severe model of ischemia and reperfusion.     

芹菜素对缺血再灌注大鼠心肌核转录因子-κB和ICAM-1表达的影响

目的研究芹菜素对缺血再灌注大鼠心肌核转录因子-κB(NF-κB)和粘附分子ICAM-1表达的影响,探讨其抗心肌缺血再灌注损伤的可能机制。方法将Wistar大鼠随机分为6组:假手术组、缺血再灌注组(IR组)、溶剂对照组、维拉帕米阳性对照组、芹菜素低、高剂量用药组。采用结扎左冠状动脉前降支制作缺血再灌注模型,心肌缺血30 min,再灌注2 h。免疫组化染色检测心肌组织的NF-κB和ICAM-1的表达.结果芹菜素组可降低心肌组织NF-κB和ICAM-1的表达,与IR组比较有显著差异(P0.05)。结论芹菜素对缺血再灌注心肌的保护作用可能与其减少心肌缺血再灌注后NF-κB和ICAM-的激活有关。     

Leukocyte trafficking and myocardial reperfusion injury in ICAM-1/P-selectin-knockout mice

P-selectin and intercellular adhesion molecule-1 (ICAM-1) mediate early interaction and adhesion of neutrophils to coronary endothelial cells and myocytes after myocardial ischemia and reperfusion. In the present study, we examined the physiological consequences of genetic deletions of ICAM-1 and P-selectin in mice. In wild-type mice, after 1 h of ischemia followed by reperfusion, neutrophil influx into the area of ischemia was increased by 3 h with a peak at 24 h and a decline by 72 h. ICAM-1/P-selectin-deficient mice showed a significant reduction in neutrophils by immunohistochemistry or by myeloperoxidase activity at 24 h but no significant difference at 3 h. Infarct size (area of necrosis/area at risk) assessed 24 h after reperfusion was not different between wild-type and deficient mice after 30 min and 1 h of occlusion. Mice with a deficiency in both ICAM-1 and P-selectin have impaired neutrophil trafficking without a difference in infarct size due to myocardial ischemia-reperfusion.     

Involvement of inhibition of nucleus GAPDH over-expression in erythropoietin's reduction of neuronal apoptosis induced by brain ischemia/reperfusion in rats

To study whether recombinant human erythropoietin (rhEPO) reduces neuronal apoptosis through inhibiting over-expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in nucleus induced by brain ischemia/reperfusion in rats, 48 adult Sprague-Dawley rats were randomly divided into 3 groups: sham, saline and EPO groups. Animal models of brain ischemia/reperfusion were established by middle cerebral artery occlusion in rats. The effects of EPO on the sizes of ischemia tissue were observed by TTC staining. The over-expression of GAPDH in nucleus was detected by Hoechst-33258 and anti-GAPDH antibody double staining. The neuronal apoptosis in penumbral was detected by Nissl's staining and Hoechst-33258 immunofluorescence, respectively. The results showed that rhEPO treatment (3 000 U/kg, three times daily, i.p.) apparently reduced the sizes of infarct brain tissue in ischemia/reperfusion rats. rhEPO inhibited over-expression of GAPDH in nucleus of apoptotic neurons. In the meantime rhEPO decreased the number of apoptotic neurons in ischemia/reperfusion rats. These results suggest that rhEPO may induced reduction of neuronal apoptosis in penumbra may be through inhibiting over-expression of GAPDH in nucleus of apoptotic neurons induced by ischemia/reperfusion. Reduction of GAPDH over-expression in nucleus may play a pivotal role in EPO inhibiting neuronal apoptosis in cerebral ischemia/reperfusion rats, providing experimental evidence for EPO neuro-protecting effects against ischemia/reperfusion.     

NO对大鼠肢体缺血/再灌注后肾脏P-选择素表达的影响及意义

目的：探讨一氧化氮（NO）对大鼠LI／R后肾脏P-选择素表达的影响及意义。方法：采用本室常规方法复制大鼠LI／R模型。将大鼠随机分为四组：对照组,LI／R组,L—Arg组和L-NAME组。观察肢体缺血4h再灌注4h后各组动物血浆NO及肌酐（Cr）、尿素氮（BUN）的变化;观察肾组织NO、髓过氧化物酶（MPO）、总一氧化氮合酶（tNOS）、诱导型一氧化氮合酶（iNOS）、结构型一氧化氮合酶（cNOS）的改变;测定尿蛋白含量、利用聚丙烯酰胺凝胶电泳法检测尿蛋白性质;免疫组织化学方法检测肾组织P-选择素（P—selectin）的蛋白表达,结合自动图象分析系统对其结果进行定量分析;肾组织切片经六氨银染色在光镜下观察其形态学改变。结果：与control组比较．LI／R组大鼠血浆NO、BUN、Cr均明显升高;肾组织MPO、NO、tNOS、iNOS均明显增加,而cNOS明显下降;尿蛋白含量增多,电泳显示,有大分子量蛋白排出;光镜下可见肾小管上皮细胞水肿,有炎细胞浸润：免疫组化结果显示：P-selectin蛋白表达明显较control组增强。与LI／R组相比,L-Arg组各项损伤指标明显减轻;肾组织P—selectin蛋白表达明显减弱;L-NAME组血浆和肾组织各项损伤指标明显加重;肾组织P—selectin蛋白表达明显增加。结论：大鼠LI／R后急性肾损伤的发生可能与P—selectin的表达有关;NO可能通过减弱P-selectin的表达及中性粒细胞的浸润,减轻LI／R后肾脏组织形态学及肾功能的损伤性变化。     

Peroxynitrite attenuates hepatic ischemia-reperfusion injury

In the present study, we examined the effects ofperoxynitrite on reperfusion injury using a rat model of hepaticischemia-reperfusion (HI/R). The left and median lobes of the liverwere subjected to 30 min of ischemia, followed by 4 h ofreperfusion. Groups A and B rats weresham-operated controls that received vehicle or peroxynitrite;groups C and D rats were subjected to HI/R and received peroxynitrite or vehicle, respectively. A dose of 2 µmol/kg body wt of peroxynitrite, diluted in saline (pH 9.0, 4°C), was administered as a bolus through a portal vein catheter at 0, 60, and120 min after reperfusion. Results showed that superoxide generation inthe ischemic lobes of the liver and plasma alanine aminotransferase(ALT) activity of group C were decreased by 43% and 45%,respectively, compared with group D. Leukocyte accumulations in the ischemic lobes of liver and circulating leukocytes were decreased by 40% and 27%, respectively, in group C vs.D. The ratios of mRNA of P-selectin and intercellularadhesion molecule-1 (ICAM-1) to glyceraldehyde-3-phosphatedehydrogenase (GAPDH) mRNA extracted from the ischemic lobes of theliver of group C were decreased compared with groupD. There were no differences between the groups A andB in terms of plasma ALT activity, circulating leukocytes,superoxide generation, and leukocyte infiltration in the ischemic lobesof the liver. Moreover, hemodynamic parameters (i.e., mean arterialblood pressure, cardiac index, stroke index, and systemic vascularresistance) were not significantly different among groups B,C, and D. These results suggest thatadministration of peroxynitrite via the portal vein only has a localeffect. Exogenous peroxynitrite at physiological concentrationsattenuates leukocyte-endothelial interaction and reduces leukocyteinfiltration. The mechanism of the reduction of leukocyte infiltrationinto ischemic lobes of the liver appears because of decreasedexpression of mRNA of P-selectin and ICAM-1. The net effect ofadministration of peroxynitrite may be to reduce adhesionmolecule-mediated, leukocyte-dependent reperfusion injury.

     

Effects of hyperbaric oxygen in circulatory shock induced by splanchnic artery occlusion and reperfusion in rats

We studied the effects of hyperbaric oxygen in a severe model of circulatory shock induced by occlusion and reperfusion of major splanchnic arteries (splanchnic artery occlusion (SAO) shock). Pentobarbital-anesthetized rats subjected to total occlusion of the superior mesenteric and the celiac arteries for 40 min developed a severe shock state, resulting in a uniformly fatal outcome after release of the occlusion. Exposure to hyperbaric oxygen at 2 ATA (atmosphere absolute) (1 ATA = 0.1 MPa) was initiated immediately after reperfusion. SAO shock rats exposed to hyperbaric oxygen maintained mean arterial blood pressure at significantly higher values throughout the postreperfusion period compared with untreated SAO shock rats (p less than 0.01), with final mean arterial blood pressures of 88 +/- 9 and 51 +/- 4 mmHg, respectively. Treatment with hyperbaric oxygen attenuated the increase in plasma activities of the lysosomal hydrolase cathepsin D (p less than 0.05), and diminished the increase of hematocrit (p less than 0.01 from untreated shock rats). Splanchnic occlusion shock rats treated with hyperbaric oxygen also exhibited a significantly higher survival rate than the untreated shock group (77 vs. 0%, respectively; p less than 0.01). Our results suggest that the beneficial effects of exposure to hyperbaric oxygen immediately after reperfusion of the splanchnic region outweigh its possible deleterious effect.     

微血栓形成和纤维蛋白原、载脂蛋白比值与大鼠急性心肌缺血再灌注无再流现象的相关性

摘要 目的：探讨微血栓形成和纤维蛋白原、载脂蛋白比值与大鼠急性心肌缺血再灌注无再流现象的相关性。方法：选择70只SD大鼠构建大鼠急性心肌缺血再灌注模型,根据再灌注后有无再流分为2组,分别为无再流组（n=42）和有再流组（n=28）。分析各组大鼠血流动力学、微血栓形成、纤维蛋白原、载脂蛋白比值以及血清细胞因子水平,并分析微血栓形成和纤维蛋白原、载脂蛋白比值与大鼠急性心肌缺血再灌注无再流现象的相关性。结果：有再流组大鼠HR和LVEDP值、纤维蛋白原水平、VCAM-1值显著高于无再流组,而SBP、DBP和LVSP值、微血栓形成数量、ApoB值和ApoB/ApoA1值、P-selectin、ICAM-1、IL-6和IL-10值则显著低于无再流组,差异均有统计学意义（P<0.05）。微血栓形成（r=0.654,P=0.005）和载脂蛋白比值（r=0.582,P=0.004）与大鼠急性心肌缺血再灌注无再流现象之间存在正相关关系;纤维蛋白原（r=-0.552,P=0.002）与大鼠急性心肌缺血再灌注无再流现象之间存在负相关关系。结论：微血栓形成和纤维蛋白原、载脂蛋白比值与急性心肌缺血再灌注无再流现象之间存在一定的相关性,三者可作为急性心肌缺血再灌注无再流现象的预测因子。     

Endothelial protective and antishock effects of a selective estrogen receptor modulator in rats

This study investigated whether idoxifene, a selective estrogen receptor modulator (SERM), exerted protective effects against ischemia-reperfusion-induced shock. Ovariectomized rats were treated with vehicle, idoxifene, or 17beta-estradiol for 4 days. Rats were subjected to splanchnic artery occlusion (SAO) followed by reperfusion (SOA/R). In vehicle-treated rats, SAO/R resulted in hypotension, hemoconcentration, increased plasma tumor necrosis factor (TNF)-alpha levels, intestinal neutrophil accumulation, and endothelial dysfunction. 17beta-Estradiol treatment increased plasma estradiol concentration and reduced SAO/R-induced tissue injury. Idoxifene treatment had no effect on plasma estradiol concentration but reduced SAO/R-induced hemoconcentration (+8.8 +/- 1.3 vs. +14 +/- 1.3% in the vehicle group, P < 0.01), TNF-alpha production (98 +/- 3.2 vs. 214 +/- 13 pg/ml, P < 0.01), and neutrophil accumulation (0.025 +/- 0.005 vs. 0.047 +/- 0.005 U/g protein, P < 0.01). It also improved endothelial function, prolonged survival time (172 +/- 3.5 vs. 147 +/- 8 min, P < 0.01), and increased survival rate (69 vs. 23%, P < 0.01). Moreover, treatment with 17beta-estradiol or idoxifene in vivo reduced TNF-alpha-induced endothelial dysfunction in vitro. Taken together, these results demonstrated that idoxifene exerted estrogen-like, endothelial-protective, and antishock effects in ovariectomized rats, suggesting that SERMs have therapeutic potential in tissue injury resulting from ischemia-reperfusion.     

Apolipoprotein A-I attenuates renal ischemia/reperfusion injury in rats

Apolipoprotein A-I (ApoA-I), the major protein component of serum high-density lipoprotein (HDL), exhibits its anti-inflammatory activity in inflammatory responses. As renal inflammation plays an important role in ischemia/reperfusion (I/R) injury of the kidney, the aim of this study was to investigate the beneficial effect of ApoA-I on renal I/R injury in rats and the underlined mechanism. Using rats subjected to renal I/R by occlusion of bilateral renal pedicles, we found that administration of ApoA-I significantly reduced serum creatinine levels, serum TNF-α and IL-1β levels as well as tissue myeloperoxidase (MPO) activity, compared with I/R controls. Moreover, ApoA-I treatment suppresses the expression of intercellular adhesion molecules-1 (ICAM-1) and P-selectin on endothelium, thus diminishing neutrophil adherence and the subsequent tissue injury. These results showed that ApoA-I reduced I/R-induced inflammatory responses, decreased renal microscopic damage and improved renal function. It seems likely that ApoA-I protects kidney from I/R injury by inhibiting inflammatory cytokines release and neutrophil infiltration and activation.     

淋浆对内毒素休克大鼠微循环障碍的干预作用

目的：探讨淋浆对内毒素休克的干预作用及其机制。方法：Wistar雄性大鼠60只,随机分为对照组、模型组和淋浆组,以颈静脉注射LPS（15 mg/kg）复制内毒素休克模型,造模15 min后,淋浆组自颈静脉注射正常淋浆（占全血量1/15）,观察对平均动脉血压（MAP）、回肠下段肠系膜微循环、细静脉壁白细胞粘附数、血浆P-选择素和细胞间粘附分子（ICAM-1）含量的影响。结果：正常淋浆可防止内毒素休克的MAP进行性下降,解除肠系膜微血管的病理性缩窄,减少白细胞在细静脉壁的粘附,改善微循环的流态,降低血浆P-选择素和ICAM-1的水平。结论：小量正常淋浆对LPS攻击导致内毒素休克的微循环障碍和低血压均有良好的干预作用,其机制与减少细胞粘附分子生成有关。     

Protective effects of n-acetylcysteine on lung injury and red blood cell modification induced by carrageenan in the rat.

Oxidative stress has been suggested as a potential mechanism in the pathogenesis of lung inflammation. The pharmacological profile of n-acetylcysteine (NAC), a free radical scavenger, was evaluated in an experimental model of lung injury (carrageenan-induced pleurisy). Injection of carrageenan into the pleural cavity of rats elicited an acute inflammatory response characterized by fluid accumulation in the pleural cavity that contained many neutrophils (PMNs), an infiltration of PMNs in lung tissues and subsequent lipid peroxidation, and increased production of nitrite/nitrate, tumor necrosis factor alpha, and interleukin 1beta. All parameters of inflammation were attenuated by NAC treatment. Furthermore, carrageenan induced an up-regulation of the adhesion molecules ICAM-1 and P-selectin, as well as nitrotyrosine and poly (ADP-ribose) synthetase (PARS), as determined by immunohistochemical analysis of lung tissues. The degree of staining for the ICAM-1, P-selectin, nitrotyrosine, and PARS was reduced by NAC. In vivo NAC treatment significantly reduced peroxynitrite formation as measured by the oxidation of the fluorescent dihydrorhodamine-123, prevented the appearance of DNA damage, an decrease in mitochondrial respiration, and partially restored the cellular level of NAD+ in ex vivo macrophages harvested from the pleural cavity of rats subjected to carrageenan-induced pleurisy. A significant alteration in the morphology of red blood cells was observed 24 h after carrageenan administration. NAC treatment has the ability to significantly diminish the red blood cell alteration. Our results clearly demonstrate that NAC treatment exerts a protective effect and clearly indicate that NAC offers a novel therapeutic approach for the management of lung injury where radicals have been postulated to play a role.     

Heat shock preconditioning reduces the formation of 8-hydroxy-2'-deoxyguanosine and 4-hydroxy-2-nonenal modified proteins in ischemia-reperfused liver of rats

Heat shock preconditioning (HSPC) is a promising strategy for providing ischemic tolerance. The objective of this study is to investigate the effectiveness of HSPC in preventing oxidative damage of cellular proteins and DNA during ischemia-reperfusion of the liver. Male Wistar rats were divided into a heat shock group (group HS) and control (group C). Forty-eight hours prior to ischemia, rats in group HS received HSPC at 42 degrees C for 15 min. All rats received hepatic warm ischemia for 30min and subsequent reperfusion. The formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), 4-hydroxy-2-nonenal (HNE) modified proteins in liver tissue, survival rate of the animals, and changes in biochemical and histological parameters were compared between groups. Heat shock protein 72 was produced only in group HS. The 7-day survival of rats was significantly better in group HS (10/10) than in group C (5/10) (p < 0.01). The serum release of alanine aminotransferase (n = 10, p < 0.01) and the concentration of adenosine triphosphate in liver tissue (n = 10, p < 0.01) 40min after reperfusion was significantly better in group HS than in group C. The formation of 8-OHdG in liver tissue measured by high-performance liquid chromatography was suppressed in group HS (p < 0.01). The production of HNE-modified proteins as determined by Western-blot analysis was also decreased in group HS. These results were also confirmed by immunohistochemical analysis. As determined by levels of 8-OHdG and HNE-modified proteins produced during ischemia-reperfusion of the liver, HSPC reduced the oxidative injury of cellular proteins and DNA in the liver tissue.     

Reduction of rat myocardial ischemia and reperfusion injury by sialyl Lewis x oligosaccharide and anti-rat P-selectin antibodies

Polymorphonuclear leukocytes (PMN) are directly involved indevelopment of ischemic myocardial injury. Adhesion of PMN toendothelial cells is an initial step that triggers a sequentialprocess leading to acute inflammatory responses. Interactionbetween P-selectin and its oligosaccharide ligand, sialyl Lewisx (sLe^x), plays an important role in the early stage of theadhesion. To examine the role of P-selectin in various animaldisease models especially in rats, we have cloned rat E- andP-selectin cDNAs and established monoclonal antibodies againstthese rat selectins. In this report, we describe the generationand characterization of anti-rat P-selectin antibodies (ARPs).These antibodies detect cell surface P-selectin on thrombin-stimulatedrat platelets. More importantly, intravenous administrationof ARP2-4 reduced infarction developed after 30 min of ischemiafollowed by 24 h of reperfusion in a rat myocardial injury model.In addition, similar protective effect was also observed byadministration of a sLe^x- oligosaccharide. These results indicatethat cell adhesion mediated via P-selectin is involved in thedevelopment of ischemia and reperfusion injury in rat heart. ischemia and reperfusion injury monoclonal antibodies selectins sialyl Lewis x     

The reduction of myocardial damage and leukocyte polymorphonuclear accumulation following coronary artery occlusion by the tyrosine kinase inhibitor tyrphostin AG 556

We investigated the effects of tyrophostin AG 556, a tyrosine kinase inhibitor, on the phenomenon of leukocyte accumulation during ischaemia and reperfusion of the myocardium. Male anaesthetized rats were subjected to total occlusion (45 min) of the left main coronary artery followed by 5 h reperfusion (MI/R). Sham myocardial ischaemia-reperfusion rats (Sham MI/R) were used as controls. Myocardial necrosis, myocardial myeloperoxidase activity (MPO), serum creatinine phosphokinase activity (CPK) serum Tumor Necrosis Factor (TNF-alpha) and Interleukin 6 (IL-6), cardiac intercellular adhesion molecule-1 (ICAM-1) and TNF-alpha expression and myocardial contractility (left ventricle dP/dt(max)) were evaluated. Myocardial ischaemia plus reperfusion in untreated rats produced marked myocardial necrosis, increased serum CPK activity (196.5 +/- 19 U/100 ml, at the end of reperfusion) and myeloperoxidase activity (MPO, a marker of leukocyte accumulation) both in the area-at-risk (4.5 +/- 0.5 U/g/tissue) and in necrotic area (8.2 +/- 1.2 U/g/tissue), reduced myocardial contractility (1,706 +/- 52 mmHg/s, at the end of reperfusion) and induced a marked increase in the serum levels of TNF-alpha (1,950 +/- 97 pg/ml, at 1 h of reperfusion) and IL-6 (998 +/- 16 U/ml, at the end of reperfusion). Finally, myocardial ischaemia-reperfusion injury also increased cardiac mRNA for TNF-alpha and ICAM-1 in the myocardium-at risk. Tyrphostin AG 556 (0.5, 1 and 2 mg/kg subcutaneously 5 min after the onset of reperfusion) lowered myocardial necrosis and myeloperoxidase activity in the area-at-risk (1.5 +/- 0.2 U/g/tissue, following the highest dose) and in necrotic area (2.9 +/- 0.3 U/g/tissue following the highest dose), decreased serum CPK activity (96 +/- 9 U/100 ml, at the end of reperfusion), lowered serum TNF-alpha and IL-6, increased myocardial contractility (2,096 +/- 88 mmHg s, at the end of reperfusion) and reduced cardiac mRNA levels for TNF-alpha and ICAM-1. The present data suggest that tyrosine kinase inhibitors protect against myocardial ischaemia-reperfusion injury by reducing leukocyte accumulation to the ischaemic myocardium.     

肠淋巴再灌注加重肠系膜上动脉闭塞性休克大鼠肺部炎症反应

目的：研究肠系膜淋巴再灌注对肠系膜上动脉闭塞,Ig（SMAO）休克大鼠肺部炎症反应的影响。方法：24只Wistar雄性大鼠均分为4组：SMAO组,MLR组,SMAO＋MLR组,SHAM组。再灌注2h后,迅速留取肺组织,一部分制备组织匀浆,检测细胞间粘附分子（ICAM-1）和晚期糖基化产物受体（RAGE）。再另外选取固定位置肺部组织放入中性甲醛中固定,用于测定肺内HMGB1、RAGE的表达。结果-SMAO与SMAO＋MLR组肺部组织匀浆ICAM-1、RAGE含量显著高于MLR与SHAM组．且SMAO＋MLR组肺组织匀浆的ICAM-1、RAGE含量高于SMAO组。肺部组织内HMGB1和RAGE在MLR组与SHAM组基本不表达,或少量表达,MLR加重了SMAO休克模型中HMOB1和RAGE的表达。结论：MLR加重SMAO休克大鼠肺部炎症反应．进一步证实肠淋巴途径在SMAO休克发病学中具有重要作用,同时证实HMGB1及RAGE在SMAO休克大鼠的炎症失常反应中起重要作用。     

Acute effects of unsaturated fatty acids in splanchnic artery occlusion shock

Diets enriched with omega-3 unsaturated fatty acids are associated with decreased hypercholesterolemia and decreased risk of ischemic and atherosclerotic diseases. We studied the acute intravascular effects of some of these unsaturated fatty acids (i.e., eicosapentaenoic acid, EPA; docosahexaenoic acid, DHA) along with omega-6 unsaturated fatty acids, (i.e., linoleic and linolenic acid) in splanchnic artery occlusion (SAO) shock in rats. Anesthetized rats subjected to total occlusion of the celiac and superior mesenteric arteries for 40 minutes followed by reperfusion usually resulted in a fatal outcome 90-120 minutes after releasing the clamps. SAO shock rats treated with the omega-3 unsaturated fatty acid, EPA, exhibited an improved survival time and rate (p less than 0.05 from vehicle) compared to those receiving only vehicle (i.e., 50% ethanol). EPA and DHA treated SAO rats also exhibited lower plasma activities of the lysosomal protease, cathepsin D, free amino-nitrogen compounds, and the cardiotoxic peptide, myocardial depressant factor. These results indicate that omega-3 unsaturated fatty acids, especially EPA, have some acute beneficial effects in SAO shock in rats.     

Heat Shock Preconditioning Reduces the Formation of 8-hydroxy-2′-deoxyguanosine and 4-hydroxy-2-nonenal Modified Proteins in Ischemia-reperfused Liver of Rats

Heat shock preconditioning (HSPC) is a promising strategy for providing ischemic tolerance. The objective of this study is to investigate the effectiveness of HSPC in preventing oxidative damage of cellular proteins and DNA during ischemia-reperfusion of the liver. Male Wistar rats were divided into a heat shock group (group HS) and control (group C). Forty-eight hours prior to ischemia, rats in group HS received HSPC at 42°C for 15 &#117 min. All rats received hepatic warm ischemia for 30 &#117 min and subsequent reperfusion. The formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), 4-hydroxy-2-nonenal (HNE) modified proteins in liver tissue, survival rate of the animals, and changes in biochemical and histological parameters were compared between groups. Heat shock protein 72 was produced only in group HS. The 7-day survival of rats was significantly better in group HS (10/10) than in group C (5/10) ( p <0.01). The serum release of alanine aminotransferase ( n =10, p <0.01) and the concentration of adenosine triphosphate in liver tissue ( n =10, p <0.01) 40 &#117 min after reperfusion was significantly better in group HS than in group C. The formation of 8-OHdG in liver tissue measured by high-performance liquid chromatography was suppressed in group HS ( p <0.01). The production of HNE-modified proteins as determined by Western-blot analysis was also decreased in group HS. These results were also confirmed by immunohistochemical analysis. As determined by levels of 8-OHdG and HNE-modified proteins produced during ischemia-reperfusion of the liver, HSPC reduced the oxidative injury of cellular proteins and DNA in the liver tissue.