Changes in the levels of lipid peroxides in regenerating rat liver and the effect of pretreatment with CoQ10

The present study was undertaken to determine whether CoQ10 pretreatment could modify cellular free radical metabolism in regenerating rat liver and enhance hepatic DNA synthesis. Male Wistar rats (250-300 g) were used. Partial 70% hepatectomy was performed according to Higgins and Anderson. CoQ10 (6 mg/kg body weight) and its solvent as a placebo were injected intravenously 1 hour before operation. Twenty-four hours or 48 hours after 70% hepatectomy resulted in 55% or 50% decreases of hepatic ATP, and marked decreases of endogenous CoQ homologs (CoQ9 and CoQ10), alpha-tocopherol and reduced glutathione (GSH) in remnant liver and was accompanied by 2.5-fold increases in lipid peroxides. However, in CoQ10-treated animals synthesis of ATP was accelerated after 48 hours after partial hepatectomy. There were no changes in the levels of CoQ9, alpha-tocopherol, or GSH or in the level of the enhanced CoQ10 in regenerating liver. The pretreatment also completely suppressed the elevation of lipid peroxide. Moreover, CoQ10 administration markedly increased hepatic DNA synthesis at 48 hours after partial hepatectomy. These results indicate that cellular damage during hepatic regeneration is in part due to lipid peroxidation, and suggest that CoQ10 is effective in the pretreatment of liver resection.     

Role of free radicals in ischemic rat liver cell injury: prevention of damage by alpha-tocopherol administration

The present study was undertaken to determine whether alpha-tocopherol pretreatment could modify cellular free radical metabolism during hepatic ischemia and subsequent reperfusion and prolong the viability of the liver. Although ischemia of the liver for 90 minutes did not permit survival of the animals, alpha-tocopherol administration (10 mg/kg of body weight) for 3 days increased the survival rate to 45.5%. The period of ischemia was accompanied by decreases in the hepatic adenosine triphosphate (ATP) level, endogenous alpha-tocopherol, and total glutathione (reduced and oxidized) without any significant increase in endogenous coenzyme Q (CoQ) homologs (CoQ9 and CoQ10) and lipid peroxide formation. The subsequent restoration of blood flow resulted in a low recovery of ATP and marked decreases in endogenous alpha-tocopherol, total glutathione, and CoQ homologs and, on the contrary, a marked increase in lipid peroxide levels. In alpha-tocopherol-treated animals, however, resynthesis of ATP was accelerated even after 90 minutes of ischemia, and there were no changes in the levels of total glutathione or CoQ homologs or in the level of the enhanced alpha-tocopherol during the reperfusion period. The pretreatment also completely suppressed the elevation of lipid peroxide levels. These results are compatible with the assumption that cellular damage caused by hepatic ischemia can be explained by free radical reaction processes during ischemia and especially reperfusion and suggest that administration of a free radical scavenger and antioxidant, alpha-tocopherol, is effective in ischemic liver cell injury.     

诱导性一氧化氮合酶抑制药对感染性休克鼠肝、肺组织学改变的影响

目的　研究诱导性一氧化氮合酶 ( i NOS)抑制药氨基胍 ( AG)和非选择性 NOS抑制药L- N-硝基精氨甲酯 ( L- NAME)对感染性休克鼠肝肺组织学改变的影响。方法　小鼠腹腔内注射 ( i.p.)内毒素 ( L PS,2 0 mg· kg- 1 )后 4小时随机分为 L PS组 ( n=60 ) ,L PS L - NAME组 ( 3 0 mg· kg- 1i.p.,n=60 )。和 L PS AG组 ( 2 0 mg· kg- 1 i.p.,n=60 )。5小时后取受试鼠的肝肺组织进行光镜和电镜检查。并观察 2 4小时内受试鼠的生存率。结果　 L PS组、L PS L- NAME组和 L PS AG组 2 4小时内生存率分别为 3 7.5 % ,5 %和 64 .3 % ( P<0 .0 5 )。光镜下 L PS组和 L PS L- NAME组肝细胞和核肿胀 ;肺间质增厚。电镜下可见 L PS组和 L PS L- NAME组可见肝细胞核、细胞膜和线粒体膜明显破坏 ;肺血气屏障明显增厚。 L PS AG组肝细胞和肺部的改变明显轻于其它两组。结论　感染性休克中 c NOS介导的一定量的 NO对器官有保护作用。以氨基胍选择性抑制 i NOS合成的 NO,疗效好于非选择性 NOS抑制药     

Effect of oxygen-free radical scavengers on survival in sepsis

Sepsis remains a leading cause of death in the surgical intensive care unit (SICU) patient following major surgery or trauma. Recent work has demonstrated that oxygen-free radicals (OFR) generated during sepsis contribute to the pathogenesis of this syndrome. The purpose of this study was to evaluate the effect of various new free radical scavengers on survival in sepsis. A total of 85 male Sprague-Dawley rats were placed into one of the following treatment groups. CONTROL: cecal ligation and puncture (CLP); PRE-AT: pretreatment with alpha-tocopherol (AT) 10 mg/100 gm SC x 3 days, and 5 mg/100 gm IV prior to CLP; AT: 20 mg/100 gm at time of CLP and 4 hours following CLP; U74006F: (21-aminosteroid which inhibits lipid peroxidation) 3 mg/kg IV at the time of and 4 hours following CLP; U78517F: (alpha-tocopherol analogue) 3 mg/kg at the time of and 4 hours following CLP. Survival was determined at various time points up to 72 hours. Pretreatment with AT resulted in improved survival, whereas the novel OFR scavengers U78517F and U74006F significantly improved survival and were efficacious without pretreatment. It was concluded that OFR scavengers can improve survival in sepsis.     

Attenuation of chloroquine-induced renal damage by alpha-lipoic acid: possible antioxidant mechanism

The toxic effect of chloroquine (CQ) has been attributed to oxidative stress with the consequences of lipid peroxidation. This study investigates the effects of alpha-lipoic acid (LA) on CQ-induced nephrotoxicity in rats. A single oral administration of CQ (970 mg/kg)-induced nephrotoxicity, manifested biochemically by a significant increase in serum creatinine and blood urea nitrogen concentrations. In addition, renal tissue from CQ-treated rats showed a significant increase in lipid peroxides measured as thiobarbituric acid reactive substances and hydroperoxides, along with significant decrease in nonenzymic antioxidants (vitamin C, vitamin E, and reduced glutathione) and enzymic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase) levels. Oral administration of LA (10, 30, or 100 mg/kg) in different doses for 10 days produced a significant protection against nephrotoxicity induced by CQ. Treatment with LA markedly reduced the elevated lipid peroxidation, restored the depleted renal antioxidant defense system. LA at 100 mg/kg was effective when compared with other doses (10 and 30 mg/kg). This was accompanied by the histopathological observations in kidney tissue. The results suggest that LA ameliorate the lipid peroxidation and the loss of cellular antioxidants, thereby protecting the CQ-induced oxidative damage in kidney.     

Attenuation of Chloroquine‐Induced Renal Damage by α‐Lipoic Acid: Possible Antioxidant Mechanism

The toxic effect of chloroquine (CQ) has been attributed to oxidative stress with the consequences of lipid peroxidation. This study investigates the effects of α‐lipoic acid (LA) on CQ‐induced nephrotoxicity in rats. A single oral administration of CQ (970 mg/kg)‐induced nephrotoxicity, manifested biochemically by a significant increase in serum creatinine and blood urea nitrogen concentrations. In addition, renal tissue from CQ‐treated rats showed a significant increase in lipid peroxides measured as thiobarbituric acid reactive substances and hydroperoxides, along with significant decrease in nonenzymic antioxidants (vitamin C, vitamin E, and reduced glutathione) and enzymic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione‐S‐transferase) levels. Oral administration of LA (10, 30, or 100 mg/kg) in different doses for 10 days produced a significant protection against nephrotoxicity induced by CQ. Treatment with LA markedly reduced the elevated lipid peroxidation, restored the depleted renal antioxidant defense system. LA at 100 mg /kg was effective when compared with other doses (10 and 30 mg/kg). This was accompanied by the histopathological observations in kidney tissue. The results suggest that LA ameliorate the lipid peroxidation and the loss of cellular antioxidants, thereby protecting the CQ‐induced oxidative damage in kidney.     

Lipid peroxidation in focal cerebral ischemia

To verify whether lipid peroxidation is associated with focal cerebral ischemia, a unilateral middle cerebral artery occlusion was carried out in rats. The concentrations of various endogenous antioxidants in the ischemic center were measured, including alpha-tocopherol and ubiquinones as lipid-soluble antioxidants and ascorbate as a water-soluble antioxidant. At 30 minutes after ischemia, alpha-tocopherol decreased to 79% of baseline, reduced ubiquinone-9 to 73%, ubiquinone-10 to 66%, and reduced ascorbate to 76%. Six hours after ischemia, alpha-tocopherol decreased to 63% and reached a plateau, whereas reduced ubiquinones and reduced ascorbate declined further to 16% and 10%, respectively, 12 hours after ischemia and then reached plateau levels. These results suggest functional and durational differences between antioxidants and lipid peroxidation in this ischemic model. Although the reciprocal increase in oxidized ubiquinones during ischemia was not observed, that of oxidized ascorbate was noted. The complementary antioxidant system between cytoplasmic and membranous components, the combination alpha-tocopherol/ascorbate, was estimated from the calculated consumption ratio of these antioxidants on the basis that the loss of these reduced antioxidants is due to neutralization of free radicals. This system is suggested to play an important role in the early ischemic period. Urate also increased during ischemia. The possible involvement of the xanthine-xanthine oxidase system in initiating free radical reactions in cerebral ischemia is also discussed.     

Disorders of the "lipid peroxidation-antioxidant" system and ways of their correction after transplantation of vascularized tissue complexes

An experimental investigation in 40 rabbits and 13 dogs has shown that arrest of blood flow in tissues is accompanied by activation of lipid peroxidation processes with reduced activity of the antioxidant system. Tissue anoxia during 4h sharply activates lipid peroxidation processes which is considerably aggravated after early performance of oxygenobarotherapy sessions (1h after revascularization). Relatively late sessions of oxygenobarotherapy (10h after the reestablishment of bloodflow) are not accompanied by activation of lipid peroxidation and decrease of the level of antioxidants of lipid nature, alpha-tocopherol acetate has a marked antioxidation effect and enhances tissue survival after anoxia.     

Fibronectin suppresses apoptosis and protects mice from endotoxic shock

Multiple-organ failure related to septicemia is a common cause of early mortality after liver transplantation. Endotoxemia following living donor hepatectomy may be a cause of postoperative death. Plasma fibronectin (Fn) exerts a broad range of biological effects on cellular adhesion, motility, differentiation, apoptosis, hemostasis, wound healing, reticuloendothelial system function, and ischemic injury. We studied the therapeutic effect of plasma Fn in mice after an intraperitoneal injection of lipopolysaccharide (LPS) and d-galactosamine (GalN). Female Balb/c mice received simultaneous intraperitoneal injection of LPS (50 microg/kg) and GalN (400 mg/kg). Thirty minutes prior to GalN/LPS administration, plasma Fn or bovine serum albumin was given intravenously. A single administration of plasma Fn (500 mg/kg) protected in dose-dependent fashion against lethal shock after GalN/LPS challenge. Plasma Fn significantly reduced the serum tumor necrosis factor-alpha, interferon-gamma, and interleukin-6 levels and significantly increased the serum interleukin-10 levels after GalN/LPS administration. Furthermore, plasma Fn significantly inhibited liver necrosis at 9 hours after GalN/LPS injection. The fraction of apoptotic-positive cells in these plasma Fn-treated mice was significantly lower than in the control group. These results support the protective treatment of endotoxin-induced liver injury by plasma Fn.     

Effects of the 21-aminosteroid U74006F on experimental head injury in mice

The ability of a novel non-glucocorticoid 21-aminosteroid U74006F to inhibit lipid peroxidation of central nervous system tissue in vitro and to enhance the early neurological recovery and survival of mice after a severe concussive head injury is described. In the in vitro studies, U74006F was found to be an extremely potent inhibitor of lipid peroxidation in an assay system where the glucocorticoid steroid methylprednisolone and the non-glucocortoid steroids U72099E and U75718A were almost completely ineffective. In the head-injury studies, unanesthetized male CF-1 mice were subjected to a 900 gm-cm closed head injury produced by a 50-gm weight being dropped 18 cm. This concussive injury resulted in immediate unconsciousness (loss of righting reflex) in all animals and death in approximately 30%. Survivors received a tail vein injection of either vehicle or U74006F (0.001 to 30 mg/kg) within 5 minutes postinjury. Their neurological status was evaluated 1 hour later using a grip test. The grip-test score indicated that intravenous administration of a single dose of U74006F resulted in a significant improvement by as much as 168.6% in the neurological status 1 hour postinjury over a broad dose range (0.003 to 30 mg/kg). A 1-mg/kg dose given intravenously within 5 minutes and again at 1 1/2 hours after a severe injury, in addition to improving early recovery, also increased the 1-week survival rate to 78.6% compared to 27.3% in vehicle-treated mice (p less than 0.02). The compound was also effective in enhancing early recovery after a more moderate injury. This study demonstrates that early treatment after severe concussive head injury with a potent inhibitor of iron-dependent lipid peroxidation can significantly benefit the injured brain in mice and promote both early neurological recovery and long-term survival.     

Investigation of lipid peroxidation in regenerating rat liver]

The purpose of this study was to estimate the effects of lipid peroxidation in regenerating rat liver. Partial 70% hepatectomy was performed in rat according to Higgings and Anderson. EPC (alpha Toc: Ascorbic acid = 6:4, radical scavenger) was injected intravenously (5mg/kg weight) one hour before operation. Lipid peroxidation in regenerating liver reached a peak at 24 hours after operation. The administration of EPC markedly suppressed the increase of lipid peroxide in the plasma and remnant liver and that of GPT after hepatectomy, with subsequent good liver regeneration ratio. Moreover, the pretreatment with EPC remarkably elevated the activity of thymidine kinase (index of DAN synthesis). The EPC administration had not notable effects on the level of plasma ketone body ratio in animal but pathologically caused early advent of glycogen granule in the remnant liver tissue after partial hepatectomy, which reflected restoration of mitochondrial energy level. The results of the present study suggest that scavenger may be useful not only for impairment of liver dysfunction but also for recovery of mitochondrial energy level and DNA synthesis after liver resection.     

The role of alpha-tocopherol and allopurinol in lipid peroxidation and mitochondrial respiration in the ischemic rat liver

In the present study, the effects of alpha-tocopherol and allopurinol in liver ischemia and reperfusion injury on lipid peroxidation and mitochondrial respiratory function were investigated in rats. Ischemia was induced in the left and median liver lobes clamping the vessels for 90 minutes. After declamping reperfusion was continued for 60 minutes. Liver tissue was taken before and 90 minutes after ischemia and 60 minutes after reperfusion to measure lipid peroxides and mitochondrial respiratory function. In one group of rats alpha-tocopherol (10mg/kg) was given intraperitoneally for three consecutive days preoperatively and in the other group allopurinol (50mg/kg) was given intravenously 10 minutes before ischemia. alpha-Tocopherol caused inhibition of increase in lipid peroxides at reperfusion and improvement in lowering of mitochondrial respiratory function. This improvement was less than previously reported, probably due to not only reperfusion injury but also ischemic injury. Allopurinol, on the other hand, caused neither such inhibition nor such improvement, suggesting the other source of oxygen-derived free radicals than xanthine oxidase system.     

D-氨基半乳糖致敏小鼠内毒素性休克模型的建立

目的 建立适用于拮抗内毒素/脂多糖(LPS)药物研究的昆明小鼠内毒素性休克模型.方法 将不同剂量的D-氨基半乳糖(D-Gal)及LPS先后注射于小鼠腹腔,根据注射药物不同分为1组:等渗盐水(NS)+LPS 80 mg/kg;2组:Ns+LPS 90 mg/kg;3组:D-Gal 500 mg/kg+NS;4组:D-Gal 500 mg/kg+LPS 25μg/kg;5组:D-Gal 500 mg/kg+LPS 50 μg/kg;6组:D-Gal 500 mg/kg+LPS 250μg/kg;7组:D-Gal 600 mg/kg+NS;8组:D-Gal 600 mg/kg+LPS 10 μg/kg;9组:D-Gal 600 mg/kg+LPS25μg/kg;10组:D-Gal 600 mg/kg+LPS 50 μg/kg.观察注射后小鼠死亡情况,计算其死亡率.选择死亡率100%的剂量组合刺激小鼠,分为对照组:注射D-Gal 600 mg/kg+Ns;LPS组:注射D-Gal 600mg/kg+LPS 50μg/kg.于注射后30、75、120 min取小鼠静脉血,检测其血清肿瘤坏死因子α(TNF-α)水平.另取小鼠10只,同前分组,于注射后5 h处死,取其肺、肝、小肠行病理学观察.结果 2、6、10组小鼠死亡率达100%(P＜0.01).对照组小鼠血清TNF-α含量保持在较低水平;LPS组伤后各时相点TNF-α含量均显著高于对照组(P＜0.01),在注射后75 min时达高峰(6365±2087)ng/L.LPS组小鼠肺、肝、小肠出现明显炎性反应;对照组仅肝脏有轻微病理改变.结论 D-Gal致敏小鼠对LPS的反应符合内毒素性休克的特征,该小鼠模型适用于拮抗LPS的药理学研究.     

Ischemic damage prevention by coenzyme Q10 treatment of the donor before orthotopic liver transplantation: biochemical and histologic findings

This study was undertaken to determine whether pretreatment of the donor rat with coenzyme Q10 (CoQ10) would protect against hepatic ischemia induced for 30 minutes at normothermic body temperature. Fresh liver transplants were used as controls (minus warm ischemia of 30 minutes) and gave a 1-week survival rate of 84.6%. CoQ10 was administered intravenously (10 mg/kg body weight) to the donor rat 1 hour before induction of warm ischemia (group A). In another group (B), the same dose was given intravenously not only to the donor rat but also to the recipient rat 1 hour before grafting. None of the placebo group survived more than 2 days. The 1-week survival rates of the groups pretreated with CoQ10 were 45.5% for group A and 50% for group B. There was no significant difference between groups A and B. A statistically significant difference was demonstrated between the placebo group and both CoQ10-treated groups (p less than 0.05). It was therefore assumed that CoQ10, accumulated in the donor liver, was a primary factor in improving survival. Serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), serum alkaline phosphatase (SALP), total bilirubin, and total protein were measured by means of light and electron microscopic examination of the liver 6 months after transplantation. Long-term-surviving rats with transplanted, ischemically damaged liver that was pretreated with CoQ10 showed a decrease in the activity of SGOT and SGPT and an increase in levels of total protein to the normal range (as well as to those levels exhibited by fresh-liver-transplanted rats) with practically no change in levels of SALP, total bilirubin, or in histologic findings. These results indicate that donor pretreatment with CoQ10 is useful for increasing survival after warm ischemic damage of rat liver grafts.     

Effect of antileukocyte adhesion molecule antibodies, nitric oxide synthase inhibitor, and corticosteroids on endotoxin shock in mice

We compared the therapeutic effects of anti-leukocyte adhesion molecule antibodies (mAbs), a nitric oxide (NO) synthase inhibitor (monomethyl-l,-arginine, NMLA), and methylprednisolone (MP) on experimental endotoxin-induced shock in mice. Lipopolysaccharide (LPS, 30mg/kg) was administered to ICR mice intraperitoneally, While 1mg/kg mAb, 5–20 mg/kg NMLA, or 30mg/kg MP was administered intravenously. The placebo group received phosphate-buffered saline. The survival rate of the placebo group 48 h after LPS injection was 36%. The administration of anti-CD11a, anti-CD18, anti-lectin cell adhesion molecule-1 (anti-LECAM-1), and MP increased the survival rate to 70, 62, 64, and 100%, respectively; however, NMLA had no significant effect. A FACS analysis revealed that the CD18 expression of granulocytes increased 12-fold within 30 min after LPS administration. MP significantly suppressed its expression. The plasma level of nitrate/nitrite increased from 20 to 260 and 1000M 4 and 16h, respectively, 20 mg/kg NMLA abolished NO production at 4h, while MP inhibited it for up to 16h. The hepatic malondialdehyde level increased from 0.50 to 2.46 nmol/mg protein at 4h. Administration of anti-CD18 and MP reduced the level to 1.80 and 1.41 nmol/mg protein, respectively, whereas NMLA did not affect it. The mAbs and MP were concluded to be useful agents for endotoxin shock. The abolition of NO production had little influence on the hepatic cellular injury associated with endotoxemia.     

Lipid peroxidation and changes in xanthine oxidase in cerebral ischemia

To verify the lipid peroxidation in the focal cerebral ischemia, the levels of alpha-tocopherol, ubiquinone and ascorbate were measured in the ischemic center in rats. The former two were endogeneous lipid soluble antioxidants and the last was a water soluble antioxidant. alpha-Tocopherol, reduced ubiquinone-9 and -10, and reduced ascorbate decreased to 79%, 73%, 66%, and 76% 0.5 hour after ischemia, respectively. alpha-Tocopherol decreased to 63% 6 hours after ischemia, and then reached a plateau, while reduced ubiquinones and reduced ascorbate declined further to 16% and 10% 12 hours after ischemia, respectively, and then reached plateau levels. These results suggest their functional and durational differences as antioxidants against lipid peroxidation in this ischemic model. Although the reciprocal increase in oxidized ubiquinones during ischemia was not observed, that in oxidized ascorbate was noted. The complementary antioxidant system between cytoplasmic and membranous components, the combination alpha-tocopherol/ascorbate, was estimated from the calculated consumption ratio of these antioxidants, assuming that the loss of these reduced antioxidants is due to neutralization of free radicals. This system was suggested to play an important role in an early ischemic period. Urate also markedly increased during ischemia. Therefore, xanthine oxidase activity was measured in rats both in normal brain and in ischemic brain induced by four-vessel occlusion method. In the control rat, the enzyme activity was 0.87 +/- 0.13 nmol/g wet brain/min at 25 degrees C (mean +/- S.D.): 92.4% was associated with the NAD-dependent dehydrogenase form and only 7.6% with the oxygen-dependent superoxide-producing oxidase form. However, the ratio of the latter form increased to 43.7% after 0.5 hour of global ischemia despite the same level in total xanthine oxidase activity. This result suggests the involvement of the oxygen free radicals generated from the xanthine oxidase pathway in the pathogenesis of the ischemic injury of the rat brain.     

Modulatory effects of diallyl sulfide against testosterone- induced oxidative stress in Swiss albino mice

Aim:To investigate the protective effect of diallyl sulfide(DAS),a constituent of garlic,against testosterone-inducedoxidative stress in male Swiss albino mice.Methods:The animals were given low(250 mg/animal)and high dose(500 mg/animal)of DAS in corn oil for 7 days along with testosterone(5 mg/kg body weight,i.p.).At the end of thestudy period,the prostate and the liver were dissected to determine various antioxidant enzyme levels(catalase,superoxide dismutase,glutathione reductase,glutathione-s-transferase)and lipid peroxidation.Results:In testoster-one treated mice,depleted antioxidant enzyme level was accompanied with enhancement in lipid peroxidation inprostate and liver.DAS significantly restored the testosterone-induced antioxidant enzymes and lipid peroxidation inthe both organs.These changes appear to be mediated by the antioxidant-enhancing effects of DAS.Conclusion:The results of the present study suggest that DAS is effective in exerting antioxidant effects by inhibiting testosterone-induced oxidative stress and might be helpful in preventing prostate cancer.(Asian J Androl 2006 Nov;8:719-723)     

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.     

Early postburn lipid peroxidation: effect of ibuprofen and allopurinol

We measured lipid peroxidation of plasma, lung, and liver in anaesthetized sheep after third-degree burns involving 30% of total body surface. Animals were resuscitated to baseline filling pressures with lactated Ringer's solution and killed 10 hours after burn. Six sheep were pretreated with ibuprofen (12.5 mg/kg) and five with allopurinol (50 mg/kg). We used conjugated dienes and malondialdehyde as measures of lipid peroxidation. Circulating conjugated dienes increased from a baseline of 0.48 +/- 0.06 to 0.64 +/- 0.05 after burn, while protein-rich burn tissue lymph flow increased up to eightfold. We also noted a significant increase in lung tissue malondialdehyde from 45 +/- 4 to 60 +/- 6 nmol/gm and liver malondialdehyde from 110 +/- 20 to 271 +/- 34 nmol/gm along with increased tissue neutrophil sequestration. Ibuprofen attenuated lung-tissue malondialdehyde but had no effect on lung inflammation, circulating lipid peroxides or burn edema, indicating that ibuprofen most likely decreased O2 radical release in lung tissue by the already-sequestered neutrophils. Allopurinol, possibly via xanthine oxidase inhibition, markedly attenuated burn QL and circulating lipid peroxides and prevented all pulmonary lipid peroxidation and inflammation, indicating that release of oxidant from burn tissue was in part responsible for local burn edema, as well as distant inflammation and oxidant release, the latter most likely from complement activation. Neither antioxidant decreased lipid peroxidation in the liver; this indicates that its mechanism of production was different from that seen in burn tissue, in plasma, or in the lung. An ischemic event resulting from a selective decrease in splanchnic blood flow may be the cause of the liver changes.     

Effect of lazaroid U-74389G and methylprednisolone on endotoxin-induced shock in mice

BACKGROUND: Lazaroids are nonglucocorticoid analogs of methylprednisolone with multiple actions. We investigated whether lazaroid U-74389G could attenuate endotoxin-induced liver injury. We hypothesized that U-74389G treatment may protect against hepatic injury by suppressing proinflammatory gene up-regulation through inhibition of activation of nuclear factor kappa B (NF-kappa B). We also compared the efficacy of U-74389G with methylprednisolone in endotoxin-induced liver injury. METHODS: Lipopolysaccharide (Escherichia coli, 30 mg/kg given intraperitoneally) was administered to male ICR mice, and U-74389G (3 mg/kg intraperitoneally) or methylprednisolone (30 mg/kg intravenously) was administered simultaneously. Phosphate-buffered saline solution (0.15 mL intravenously) was administered to mice that served as a control group. RESULTS: U-74389G and methylprednisolone treatment significantly increased survival rates 48 hours after lipopolysaccharide injection and protected against lipopolysaccharide-induced liver injury in vivo, as indicated by the decreased hepatic lipid peroxidation, tumor necrosis factor-alpha, and inducible nitric oxide synthase messenger RNA formation, hepatic enzyme release, and neutrophil infiltration in the liver. U-74389G and methylprednisolone also showed inhibitory effects on NF-kappa B activation in the liver. CONCLUSIONS: These findings suggest that U-74389G can suppress proinflammatory gene up-regulation through inhibition of NF-kappa B activation and that it is a promising new antioxidant drug for the treatment of endotoxin shock.