Relationship between endothelin and the pathophysiology of tissue factor-induced and lipopolysaccharide-induced disseminated intravascular coagulation in rats: a study examining the effect of an endothelin receptor antagonist.

We investigated the relationship between endothelin, a potent vasoconstrictor peptide, and the pathophysiology of disseminated intravascular coagulation (DIC), using two models of DIC. Experimental DIC was induced by sustained infusion of 50 mg/kg lipopolysaccharide (LPS), or 3.75 U/kg thromboplastin, for 4 h via the rat tail vein. The effect of administration of a non-selective endothelin receptor antagonist (TAK-044) (2, 10, or 50 mg/kg, from -0.5 to 4 h) on thromboplastin-induced DIC was not significant. However, LPS-induced elevation of alanine aminotransferase, creatinine and glomerular fibrin deposition was significantly suppressed by co-administration of TAK-044 in a dose-dependent manner, although no effect of TAK-044 was observed on the platelet count, fibrinogen concentration or the level of thrombin-antithrombin complex. Moreover, plasma levels of D-dimer, which reflect the grade of fibrinolysis of cross-linked fibrin, were significantly increased by co-administration of each dose of TAK-044 in the LPS-induced DIC model in rats. Our results suggest that vasoconstriction, as well as depressed fibrinolysis, contribute to severe organ dysfunction in LPS-induced, but not thromboplastin-induced, DIC, and that endothelin plays a role in the development of organ injury in LPS-induced DIC in rats.     

Effects of alterations of glomerular fibrin deposition on renal inflammation in rats at different age stages

Recent data indicated that aging accelerated glomerular fibrin deposition induced by lipopolysaccharide (LPS) in mice. Our hypothesis was that aging may exacerbate glomerular inflammatory responses induced by glomerular fibrin deposition. Both young and aged rats with glomerular fibrin deposition induced by LPS were treated with tranexamic acid (TA) and TA plus urokinase (UK). Infiltrating inflammatory cells and expressions of monocyte chemoattractant protein 1, intercellular adhesion molecule 1, and vascular endothelial-cadherin were markedly upregulated in the LPS+TA group compared with the LPS group. Reduction of fibrin deposition in the LPS+TA+UK group was associated with downregulation of the above indices (p < .05), whereas the alteration of vascular endothelial-cadherin protein expression was negatively correlated with the fibrin deposition. There were also significant differences in increased expressions of monocyte chemoattractant protein 1 and intercellular adhesion molecule 1 between young and aged rats. These in vivo data demonstrated that fibrin deposition contributed to glomerular inflammatory responses, which could be exacerbated by aging.     

Heparin blunts endotoxin-induced coagulation activation

BACKGROUND: Lipopolysaccharide (LPS) is a major trigger of sepsis-induced disseminated intravascular coagulation (DIC) via the tissue factor (TF)/factor VIIa-dependent pathway of coagulation. Experimental endotoxemia has been used repeatedly to explore this complex pathophysiology, but little is known about the effects of clinically used anticoagulants in this setting. Therefore, we compared with placebo the effects of unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) on LPS-induced coagulation. METHODS AND RESULTS: In a randomized, double-blind, placebo-controlled trial, 30 healthy male volunteers received LPS 2 ng/kg IV followed by a bolus-primed continuous infusion of UFH, LMWH, or placebo. In the placebo group, activation of coagulation caused marked increases in plasma levels of prothrombin fragment F(1+2) (P<0.01) and polymerized soluble fibrin, termed thrombus precursor protein (TpP; P<0.01); TF-positive monocytes doubled in response to LPS, whereas levels of activated factor VII slightly decreased and levels of TF pathway inhibitor remained unchanged. UFH and LMWH markedly decreased activation of coagulation caused by LPS, as F(1+2) and TpP levels only slightly increased; TF expression on monocytes was also markedly reduced by UFH. TF pathway inhibitor values increased after either heparin infusion (P<0.01). Concomitantly, factor VIIa levels dropped by >50% at 50 minutes after initiation of either heparin infusion (P<0.01). CONCLUSIONS: This experimental model proved the anticoagulatory potency of UFH and LMWH in the initial phase of experimental LPS-induced coagulation. Successful inhibition of thrombin generation also translates into blunted activation of coagulation factors upstream and downstream of thrombin.     

Lepirudin blunts endotoxin-induced coagulation activation

During sepsis, lipopolysaccharide (LPS) triggers the development of disseminated intravascular coagulation (DIC) via the tissue factor-dependent pathway of coagulation resulting in massive thrombin generation and fibrin polymerization. Recently, animal studies demonstrated that hirudin reduced fibrin deposition in liver and kidney and decreased mortality in LPS-induced DIC. Accordingly, the effects of recombinant hirudin (lepirudin) was compared with those caused by placebo on LPS-induced coagulation in humans. Twenty-four healthy male subjects participated in this randomized, double-blind, placebo-controlled, parallel group study. Volunteers received 2 ng/kg LPS intravenously, followed by a bolus-primed continuous infusion of placebo or lepirudin (Refludan, bolus: 0.1 mg/kg, infusion: 0.1 mg/kg/h for 5 hours) to achieve a 2-fold prolongation of the activated partial thromboplastin time (aPTT). LPS infusion enhanced thrombin activity as evidenced by a 20-fold increase of thrombin-antithrombin complexes (TAT), a 6-fold increase of polymerized soluble fibrin, termed thrombus precursor protein (TpP), and a 4-fold increase in D-dimer. In the lepirudin group, TAT increased only 5-fold, TpP increased by only 50%, and D-dimer only slightly exceeded baseline values (P <.01 versus placebo). Concomitantly, lepirudin also blunted thrombin generation evidenced by an attenuated rise in prothrombin fragment levels (F(1 + 2), P <. 01 versus placebo) and blunted the expression of tissue factor on circulating monocytes. This experimental model proved the anticoagulatory potency of lepirudin in LPS-induced coagulation activation. Results from this trial provide a rationale for a randomized clinical trial on the efficacy of lepirudin in DIC. (Blood. 2000;95:1729-1734)     

Beneficial effect of JTV-803, a new synthetic inhibitor of activated factor X, against both lipopolysaccharide-induced and tissue factor-induced disseminated intravascular coagulation in rat models.

We examined whether JTV-803, a specific activated factor X inhibitor independent of antithrombin III (ATIII), is effective against disseminated intravascular coagulation (DIC) in rat models induced by tissue factor (TF) or lipopolysaccharides (LPS). In male Wistar rats, DIC was induced by a 4 h infusion of thromboplastin (3.75 U/kg) or LPS (50 mg/kg). The rats were given JTV-803 (0.3 or 3 mg/kg, bolus intravenously) (JTV-803 groups) or low molecular weight heparin (LMWH groups) (200 U/kg, bolus intravenously) prior to an injection of TF or LPS. The results showed that JTV-803 was dose-dependently effective against DIC in both TF-induced and LPS-induced rat models. This anti-DIC effect of JTV-803 at higher doses was almost equivalent to that of LMWH in both types of DIC. Plasma ATIII activity was more prominent in the group treated with JTV-803 than in that treated with LMWH. None of rats died in the TF-induced DIC model with or without drug administration. On the contrary, seven of 22 rats died (mortality rate, 31.8%) in the LPS-induced DIC model without drug administration. Although the mortality rate of rats induced with LPS and treated with LMWH was quite high (6/16, 37.5%), none of the LPS-induced rats treated with JTV-803 died. These findings suggested that JTV-803 can treat both TF-induced and LPS-induced DIC models, and that this drug has greater potential in preserving ATIII and in improving the prognosis of DIC.     

Pathophysiology of disseminated intravascular coagulation (DIC) progresses at a different rate in tissue factor-induced and lipopolysaccharide-induced DIC models in rats.

Tissue factor (TF) and lipopolysaccharide (LPS) are frequently used to induce disseminated intravascular coagulation (DIC) in experimental animal models. Although the pathophysiology of DIC may differ depending on which agent is used for induction, previous studies on models of DIC have not distinguished which DIC-inducing agent was used. In the present paper, we evaluate the characteristics of TF-induced and LPS-induced DIC using two types of DIC models, with special reference to selected hemostatic parameters and pathological findings within the kidney. Male Wistar rats were administered TF (3.75 U/kg; sustained infusion for 4 h) or LPS (30 mg/kg; sustained infusion for 4 h) via the tail vein, and blood sampling was performed at 0, 1, 3, 4, 5, 7, 9, 11, and 28 h. Judging from changes in the levels of thrombin-antithrombin complex, fibrinogen levels, and platelet counts, it is reasonable to conclude that the severity of both types of experimental DIC is similar with regard to hemostatic activation and consumption coagulopathy. A marked elevation in the level of D-dimer was noted without any organ dysfunction or much fibrin deposition in the kidney upon administration of TF. However, a markedly prolonged period of elevation in plasminogen activator inhibitor activity, a prolonged depression in antithrombin III activity, severe organ failure, and a markedly prolonged period of fibrin deposition in the kidney was observed following LPS administration. A modest number of the rats from the TF-induced DIC model died during the experimental period, whereas a large number of rats died during LPS-induced DIC, especially after 9 h. Since the time course of the pathophysiology differed remarkably among the TF-induced and LPS-induced DIC models in rats, we recommend that TF-induced and LPS-induced DIC be approached as distinct models in order to determine the implications of their experimental and clinical use.     

All-trans retinoic acid is partially effective against lipopolysaccharide-induced but not against tissue-factor-induced disseminated intravascular coagulation in rat models.

All-trans retinoic acid (ATRA) has been introduced to the management of acute promyelocytic leukemia (APL) as a differentiation treatment. This drug not only causes complete remission, but also improves disseminated intravascular coagulation (DIC) without adding anticoagulants in APL. We have attempted to determine whether ATRA is effective against DIC in rat models induced by tissue factor (TF) or lipopolysaccharide (LPS), because the anticoagulant effect of ATRA has been considered to induce thrombomodulin upregulation and TF downregulation on endothelial cells as well as on APL cells. In male Wistar rats, DIC was induced by a 4-h infusion of thromboplastin (3.75 U/kg) or lipopolysaccharide (30 mg/kg). The rats were given ATRA orally each day at a dose of 100 mg/kg per day for 1 week before the injection of TF or LPS in ATRA treatment groups, or given low molecular weight heparin (LMWH) 10 min before the injection of TF or LPS (200 U/kg, bolus intravenously) in LMWH treatment groups. No significant changes in hemostatic parameters or markers of organ dysfunction were caused by the ATRA administration, while DIC was significantly improved by LMWH in the TF-induced model. DIC was significantly improved by both ATRA and LMWH in the LPS-induced model. These findings suggested that ATRA was useful for treating DIC only in the LPS-induced model, and that drug efficacy should be carefully assessed because the agents used to induce DIC considerably influenced the outcome.     

Endotoxin-induced activation of the coagulation cascade in humans: effect of acetylsalicylic acid and acetaminophen.

During Gram-negative septic shock, lipopolysaccharide (LPS, endotoxin) induces tissue factor (TF) expression. TF expression is mediated by nuclear factor kappaB and amplified by activated platelets. TF forms a highly procoagulant complex with activated coagulation factor VII (FVIIa). Hence, we hypothesized that aspirin, which inhibits LPS-induced, nuclear factor kappaB-dependent TF expression in vitro and platelet activation in vivo, may suppress LPS-induced coagulation in humans. Therefore, we studied the effects of aspirin on systemic coagulation activation in the established and controlled setting of the human LPS model. Thirty healthy volunteers were challenged with LPS (4 ng/kg IV) after intake of either placebo or aspirin (1000 mg). Acetaminophen (1000 mg) was given to a third group to control for potential effects of antipyresis. Neither aspirin nor acetaminophen inhibited LPS-induced coagulation. However, LPS increased the percentage of circulating TF(+) monocytes by 2-fold. This increase was associated with a decrease in FVIIa levels, which reached a minimum of 50% 24 hours after LPS infusion. Furthermore, LPS-induced thrombin generation increased plasma levels of circulating polymerized, but not cross-linked, fibrin (ie, thrombus precursor protein), whereas levels of soluble fibrin were unaffected. In summary, a single 1000-mg dose of aspirin did not decrease LPS-induced coagulation. However, our study showed, for the first time, that LPS increases TF(+) monocytes, substantially decreases FVIIa levels, and enhances plasma levels of thrombus precursor protein, which may be a useful marker of fibrin formation in humans.     

Pretreatment of curcumin attenuates coagulopathy and renal injury in LPS-induced endotoxemia

Disseminated intravascular coagulation (DIC) is a lethal situation in severe infections, characterized by the systemic formation of microthrombi complicated with bleeding tendency and organ dysfunction. Current clinical trials are not promising. In this study, we investigated the protective effect of curcumin in a lipopolysaccharide (LPS)-induced DIC model in rats. Experimental DIC was induced by sustained infusion of LPS (10 mg/kg body weight) for 4 h through the tail vein. Curcumin (60 mg/kg body weight) was given intraperitoneally 3 h before LPS infusion. Results showed that, in vivo, curcumin reduced the mortality rate of LPS-infused rats by decreasing the circulating TNF-alpha levels and the consumption of peripheral platelets and plasma fibrinogen. Furthermore, in vivo curcumin also has the effect of preventing the formation of fibrin deposition in the glomeruli of kidney. These results reveal the therapeutic potential of curcumin in infection-related coagulopathy of DIC.     

调控纤维蛋白水平对不同鼠龄肾脏炎症反应的影响

目的　探讨调控纤维蛋白在不同鼠龄肾脏沉积水平对肾脏炎症反应的影响及其机制。　方法　青年及老年鼠均随机分4组,对照组予生理盐水腹腔注射;脂多糖组腹腔注射脂多糖,氨甲环酸组注射脂多糖加氨甲环酸,尿激酶组注射脂多糖及氨甲环酸加尿激酶。应用激光共聚焦显微镜分析纤维蛋白沉积,应用RT PCR、免疫组化及蛋白质印迹法分别检测肾组织细胞间黏附分子(ICAM 1)基因和蛋白质表达。　结果　(1)青年与老年鼠比较脂多糖、氨甲环酸、尿激酶组纤维蛋白、ICAM 1表达差别均有统计学意义(P<0 05);(2)氨甲环酸组与脂多糖、尿激酶组间比较纤维蛋白、ICAM 1基因及蛋白质表达差异均有统计学意义(P<0 05)。　结论　纤维蛋白可上调ICAM 1基因及蛋白质表达,促进肾脏炎症反应;增龄能促进肾脏纤维蛋白沉积及炎症反应。     

Role of hepatic fibrin in idiosyncrasy-like liver injury from lipopolysaccharide-ranitidine coexposure in rats

Coadministration of nonhepatotoxic doses of the histamine 2-receptor antagonist ranitidine (RAN) and bacterial lipopolysaccharide (LPS) results in hepatocellular injury in rats, the onset of which occurs in 3 to 6 hours. This reaction resembles RAN idiosyncratic hepatotoxicity in humans. Early fibrin deposition occurs in livers of rats cotreated with LPS/RAN. Accordingly, we tested the hypothesis that the hemostatic system contributes to liver injury in LPS/RAN-treated rats. Rats were given either LPS (44.4 x 10(6) EU/kg) or its vehicle, then RAN (30 mg/kg) or its vehicle 2 hours later. They were killed 2, 3, 6, 12, or 24 hours after RAN treatment, and liver injury was estimated from serum alanine aminotransferase activity. A modest elevation in serum hyaluronic acid, which was most pronounced in LPS/RAN-cotreated rats, suggested altered sinusoidal endothelial cell function. A decrease in plasma fibrinogen and increases in thrombin-antithrombin dimers and in serum concentration of plasminogen activator inhibitor-1 occurred before the onset of liver injury. Hepatic fibrin deposition was observed in livers from LPS/RAN-cotreated rats 3 and 6 hours after RAN. Liver injury was abolished by the anticoagulant heparin and was significantly attenuated by the fibrinolytic agent streptokinase. Hypoxia, one potential consequence of sinusoidal fibrin deposition, was observed in livers of LPS/RAN-treated rats. In conclusion, the results suggest that the hemostatic system is activated after LPS/RAN cotreatment and that fibrin deposition in liver is important for the genesis of hepatic parenchymal cell injury in this model.     

Immunodepletion of extrinsic pathway inhibitor sensitizes rabbits to endotoxin-induced intravascular coagulation and the generalized Shwartzman reaction

We have reported earlier that immunodepletion of extrinsic pathway inhibitor (EPI) sensitizes rabbits to disseminated intravascular coagulation (DIC) induced by infusing a low concentration of tissue factor (TF). We now describe the effect of immunodepletion of EPI in rabbits administered endotoxin. Cortisone-treated rabbits were administered anti-rabbit EPI immunoglobulin (IgG) or Fab fragments or were administered control nonimmune material before an injection of endotoxin. In four of seven rabbits administered anti-EPI, plasma EPI activity levels were reduced by 70% to 80% of initial levels for 6 to 8 hours. In these rabbits the endotoxin induced extensive DIC, as evidenced by substantial decreases in fibrinogen, factor V, factor VIII, and platelets, and gross hemorrhagic necrosis of the kidneys due to massive deposition of fibrin in the glomerular microcirculation (the generalized Shwartzman reaction). In three rabbits administered anti-EPI, plasma EPI levels were only transiently reduced. In these rabbits and in four rabbits administered nonimmune IgG or Fab, endotoxin induced minimal to moderate intravascular clotting and deposits of fibrin were not found in the glomerular capillaries. Because it is believed that TF expressed on monocytes triggers endotoxin-induced coagulation, these data are taken as evidence that EPI functions as a natural anticoagulant that can regulate factor VIIa/TF activity expressed on cell surfaces in vivo. They support a hypothesis that EPI prevents thrombotic complications that might otherwise result from exposure of blood to cytokine-induced generation of small amounts of TF on cell surfaces in many inflammatory and infectious disease states.     

Effects of low molecular weight heparin,alone or combined with antithrombin III,on mortality,fibrin deposits and hemostatic parameters in endotoxin-induced disseminated intravascular coagulation in rabbits

The effect of low molecular weight heparin (LMWH) with or without antithrombin III (AT III) has been studied in a rabbit model of disseminated intravascular coagulation (DIC) induced by continuous infusion of 100 μg/kg/hr of Escherichia coli endotoxin for 6 hr. LMWH (5 and 10 IU/kg/hr/6 hr), alone or in combination with AT III (20 U/kg/hr/6 hr), or saline were administered simultaneously with endotoxin. Hemostatic markers at 0, 2, and 6 hr as well as kidney fibrin deposits and the mortality rate at 24 hr were determined. Rabbits receiving only endotoxin showed an impairment in hemostasis, as well as high kidney fibrin deposits and a high mortality rate. LMWH alone did not exert any effect. The simultaneous infusion of LMWH and AT III exerted a beneficial effect on the hemostatic markers and reduced the kidney fibrin deposits as well as the mortality rate in a LMWH dose-dependent manner. Fibrinogen and protein C consumption were significantly higher and renal fibrin deposits more intense in the rabbits that had died in the first 24 hr. There was also a significant positive correlation between kidney fibrin deposits and platelets, fibrinogen, and protein C consumption, taking the whole rabbit population. It is concluded that the simultaneous infusion of LMWH and AT III is useful in this DIC model and would make it possible to reduce significantly the AT III doses used when AT III is given alone. Am. J. Hematol. 60:6–11, 1999. © 1999 Wiley-Liss, Inc.     

Prednisolone inhibits endotoxin-induced disseminated intravascular coagulation and improves mortality in rats: importance of inflammatory cytokine suppression.

In order to determine whether prednisolone has a protective effect against the development of disseminated intravascular coagulation (DIC), we measured the effect of prednisolone on changes in hemostatic parameters and plasma levels of inflammatory cytokines in endotoxin-treated rats. Decreases in platelet count and fibrinogen levels, prolongation of prothrombin time, and increases in the plasma fibrin degradation products and levels of thrombin-antithrombin III (TAT) complex following the administration of endotoxin, all of which are associated with DIC, were significantly suppressed by the administration of prednisolone. Heparin administration significantly suppressed changes in all these parameters except for the decrease in platelet count. The combination of prednisolone and heparin was more effective than either treatment alone. In order to determine whether these effects of prednisolone are correlated with the suppression of inflammatory cytokine production, we examined the relationship between changes in plasma levels of cytokine, the hemostatic parameters listed above, and mortality using a number of intervention regimens designed to alter events of the experimentally induced DIC. Changes in hemostatic parameters associated with DIC following 30 mg/kg per 4 h of endotoxin infusion were significantly suppressed by treatment with 1 mg/kg prednisolone 30 min before beginning endotoxin infusion, followed by administration of 250 U/kg heparin 2 h after the start of endotoxin infusion (prednisolone-endotoxin-heparin regimen). The heparin and prednisolone were administrated subcutaneously. The administration of prednisolone and heparin in the reverse order (i.e. heparin first and prednisolone second: heparin-endotoxin-prednisolone regimen) also suppressed changes in hemostatic parameters, albeit to a smaller degree. Cytokine production was also significantly suppressed by the first treatment, but was not affected by the regimen in which heparin was administered first. Administration of prednisolone alone or heparin alone 30 min before endotoxin significantly reduced the number of renal glomeruli with fibrin thrombi. Plasma levels of creatinine and alanine transferase were reduced only by prednisolone. Increased plasma levels of interleukin-1beta, tissue necrosis factor-alpha and interleukin-6 were suppressed by prednisolone but not by heparin, and there were significant correlations between plasma levels of TAT and cytokines. Prednisolone was more effective than heparin in reducing mortality at 24 h after 100 mg/kg over 4 h of endotoxin infusion (four of 20 versus 15 of 20 deaths for prednisolone and heparin, respectively). These findings suggest that prednisolone inhibits the development of endotoxin-induced DIC and reduces mortality by a different mechanism than heparin, possibly through suppressing the production of inflammatory cytokines. Prednisolone may be efficacious in preventing DIC and multiple organ dysfunction caused by endotoxin.     

胰岛素对内毒素所致的急性肺损伤的防治作用

目的 观察胰岛素（insulin,ISL）对内毒素（LPS）引起的兔急性肺损伤（ALI）的预防与治疗作用,并初步探讨其作用机制。方法 将新西兰兔随机分为生理盐水（NS）对照组、LPS组、ISL+LPS组及LPS+ISL组,气管内滴注LPS建立兔ALI模型。采用微量注射泵经兔耳缘静脉滴注不同的液体,NS组和LPS组:滴注生理盐水;ISL+LPS组:滴注ISL混合液（ISL+葡萄糖+KCl）0.5 h后,再于气管内滴注LPS;LPS+ISL组:先经气管内滴注LPS 0.5 h后,再滴注ISL混合液。滴注时间持续4 h,期间监测兔平均颈总动脉压（mCAP）、血糖及血钾的变化。实验结束后处死实验动物,取肺组织观察形态学改变、测定肺湿/干质量的比值（W/D）,并分别用亚硝酸盐显色法和硫代巴比妥法测定肺组织匀浆中超氧化物歧化酶（SOD）和丙二醛（MDA）的含量及活性。结果 LPS组兔随时间 mCAP逐渐下降,实验结束时下降至(8.09±1.12)kPa,与NS组相比差异显著(P<0.05)。应用ISL预防和治疗后, mCAP下降的趋势缓慢,基本保持平稳,与LPS组相比有显著性差异（P<0.05）。LPS组兔的血糖随时间延长逐渐增高,实验结束时达峰值至(12.8±5.6)mmol/L,与NS组相比差异显著（P<0.05）。应用ISL预防和治疗后,兔的血糖随时间变化不明显,与LPS组相比差异明显（P<0.05）。实验期间各组兔的血钾基本保持平稳。形态学观察表明,LPS组肺组织水肿有点、片状出血,大量炎性细胞浸润,肺泡间隔显著增厚,肺泡腔变窄,结构消失。ISL+LPS组及LPS+ISL组的肺损伤明显减轻,肺组织结构均趋于正常;肺泡腔及支气管腔炎细胞及渗出物明显减少。与NS组相比,LPS组兔的肺W/D明显增加（P<0.05）,肺组织匀浆中SOD的活性显著降低（P<0.05）,MDA的含量显著升高（P<0.05）;而ISL+LPS组及LPS+ISL组兔的肺W/D明显减少（P<0.05）,肺组织匀浆中SOD的活性显著增加（P<0.05）,MDA的含量显著降低（P<0.05）。结论 ISL对LPS所致兔ALI具有预防与治疗的作用,其作用可能与抑制肺组织中的氧化应激作用有关。     

Endotoxin-induced mortality in bile duct-ligated rats after administration of reconstituted high-density lipoprotein

Cholestatic patients have substantial morbidity because of increased susceptibility to endotoxin (lipopolysaccharide [LPS]). Although reconstituted high-density lipoprotein (rHDL) can bind and neutralize LPS, cholestasis is associated with a near complete absence of HDL. Effects of rHDL infusion on the outcome of LPS-induced inflammatory responses in cholestatic rats were determined. Bile duct-ligated (BDL) and sham rats were treated with rHDL or saline and challenged with LPS. Distribution of cholesterol over the lipoprotein subclasses changed by ligation: levels in low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) were increased 2-fold and 5-fold, respectively, and were decreased in HDL 2-fold. rHDL treatment did not affect cholesterol distribution. LPS was mainly found in the HDL fraction, and ligation affected only levels of HDL-bound LPS (50% decrease; P<.05). Although rHDL infusion effectively normalized the lipoprotein-bound LPS distribution, it resulted in increased sensitivity (mortality: 88% in the ligation + rHDL group versus 44% in the ligation + saline group, 25% in the sham + saline group, and 0% in the sham + rHDL group, P <.05). In accordance with these results, plasma tumor necrosis factor (TNF) was significantly highest in the BDL + rHDL group at several hours after LPS challenge as well as the accumulation of LPS in the liver (P<.05). rHDL infusion leads to increased LPS-induced mortality in cholestatic rats. These results sharply contrast with the protective effects of rHDL suppletion in experimental endotoxemia in animals and human volunteers without biliary obstruction and suggest that there may be danger in administration of rHDL to cholestatic patients.     

Down-regulated expression of AQP5 on lung in rat DIC model induced by LPS and its effect on the development of pulmonary edema

Disseminated intravascular coagulation (DIC) is an acquired syndrome characterized by the widespread activation of coagulation, which leads to failure of multiple organs in the body. DIC of rat with lipopolysaccharide (LPS) is associated with subsequent pulmonary edema. Lung tissue is highly water permeable and expresses several aquaporins (AQPs). We therefore explored whether AQP5 involved in the pathogenesis of LPS-induced lung edema. The rats were intravenously infused with LPS (30 mg/kg) for 4 h, 6 h, 8 h, 10 h, and 12 h to induce DIC. Platelets count (PLT), D-Dimer (DD), fibrinogen (FIB), prothrombin time (PT), and activated partial thromboplastin time (APTT) were determined. Real-time quantitative PCR and Western blot were used to analyze the mRNA and protein expression of AQP5. Lung samples were stained with hematoxylin-eosin and lung wet/dry weight (W/D) ratios were measured. Here, we demonstrated that PLT and FIB values were significant decreased, the values for DD, PT, and APTT were marked increased, microthrombus was observed in lung specimens, and simultaneously with the AQP5 showed down-regulated expression following LPS infused from 4 h to 12 h. However, histopathological changes such as pulmonary edema and the increased lung W/D weight ratio were observed after LPS infused from 6 h to 12 h. These results indicated that the decreased expression of AQP5 maybe induce liquid transport obstacles between alveolar and capillary, and provides the report of AQP5 gene regulation, revealing the pathogenesis of pulmonary edema in DIC model of rat.     

Antithrombin III injection via the portal vein suppresses liver damage

AIM: To investigate the effects of antithrombin III (AT III) injection via the portal vein in acute liver failure.METHODS: Thirty rats were intraperitoneally challenged with lipopolysaccharide (LPS) and D-galactosamine (GalN) and divided into three groups: a control group; a group injected with AT III via the tail vein; and a group injected with AT III via the portal vein. AT III (50 U/kg body weight) was administrated 1 h after challenge with LPS and GalN. Serum levels of inflammatory cytokines and fibrin degradation products, hepatic fibrin deposition, and hepatic mRNA expression of hypoxia-related genes were analyzed.RESULTS: Serum levels of alanine aminotransferase, tumor necrosis factor-α and interleukin-6 decreased significantly following portal vein AT III injection compared with tail vein injection, and control rats. Portal vein AT III injection reduced liver cell destruction and decreased hepatic fibrin deposition. This treatment also significantly reduced hepatic mRNA expression of lactate dehydrogenase and heme oxygenase-1.CONCLUSION: A clinically acceptable dose of AT III injection into the portal vein suppressed liver damage, probably through its enhanced anticoagulant and anti-inflammatory activities.     

Lipid peroxidation and deformability of red blood cells in experimental sepsis in rats: The protective effects of melatonin

Sepsis has been associated with a lipopolysaccharide (LPS) induced bacterial infection and causes biochemical, hemodynamic and physiological alterations in a system. Erythrocyte deformability is very critical for a microcirculatory system to function effectively. Hence, we were interested in examining the effects of a potent antioxidant, melatonin (Mel), on lipid peroxidation and deformability of eythrocytes in LPS-induced experimental sepsis. Male Swiss Albino rats were used in 6 groups, each group comprising of 10 animals. The first group was the control, and the other groups were administered LPS (10 mg/kg, i.p.), Mel (10 mg/kg, i.p.), LPS + L-NAME (5 mM, i.p.), Mel + LPS and Mel + LPS + L-NAME, respectively. Deformability of the RBCs decreased significantly (p < 0.05) in the LPS group in comparison to all other groups. This reduction was prevented with both L-NAME and Mel, but was not as significant as when administering L-NAME or Mel alone. This result was adversely seen in nitric oxide levels, i.e. RBCD was reduced when the NO levels were higher. Therefore in the Mel group the NO levels were reduced while the RBCD enhanced. In addition to these, as an index of lipid peroxidation, the Malondialdehyde levels were elevated in LPS groups whereas the deformability was reduced. This lipid peroxidation was suppressed by Mel and/or L-NAME significantly, where the RBCD was enhanced. These results show that, Melatonin can elevate the RBCD in experimental sepsis due to its nitric oxide scavenging activity and antioxidant effect as revealed by lipid peroxidation.     

The course of disseminated intravascular coagulation is predicted by changes in thrombin-antithrombin III complex levels--is there any difference between treatment with standard heparin or low-molecular-weight heparin?

Changes in thrombin-antithrombin III complex (TAT) over a one week period studied in 42 cases of disseminated intravascular coagulation (DIC); 19 treated with standard (or unfractionated) heparin (UFH) and 23 treated with low-molecular-weight heparin (LMWH). Closer examination of short term changes in TAT (determined 2, 6, 12, 24, 48, and 72 h after starting anticoagulant therapy) was performed in ten cases of DIC; six treated with UFH and four treated with LMWH. In twelve of the 19 cases of DIC treated with UFH and 19 of the 23 cases treated with LMWH, plasma levels of TAT decreased one day after starting anticoagulant therapy, and no exacerbation of DIC was observed for the following week. In the other cases, these levels further increased and most patients had persistently high levels of TAT for the next week. Plasma levels of TAT were significantly lower in patients treated with LMWH than in those treated with UFH, which may suggest that LMWH is more beneficial in DIC. A transient increase in plasma levels of TAT was observed 6 h after the start of anticoagulant therapy in two of the six cases treated with UFH and one of the four cases treated with LMWH. From these results we conclude that fluctuation of TAT was not influenced by the type of heparin (UFH or LMWH), and that the course of DIC for the following week can be predicted by the changes in plasma TAT levels one day after starting anticoagulant therapy.