Diphosphoryl lipid A protects rats from lethal hyperoxia.

Bacterial endotoxin has been shown to protect rats from lethal hyperoxia. The structure of endotoxin contains diphosphoryl lipid A (DPL) as the lipid backbone stripped of protein and polysaccharides. DPL is the component of the endotoxin molecule that has been demonstrated (in previous studies) to be responsible for the immunologic, mitogenic, pyrogenic, and lethal properties of endotoxin. Monophosphoryl lipid A (MPL) is a nonpyrogenic, nontoxic modification of the DPL molecule that retains its immunostimulatory and mitogenic properties. We hypothesized that DPL may be the actual active component of endotoxin that protects rats from lethal hyperoxia. We also hypothesized that the protection from hyperoxia that is afforded by the DPL component may be related to endogenous release of tumor necrosis factor alpha which should allow MPL to also be protective. To test these hypotheses, we performed a series of experiments in which rats were treated with endotoxin, DPL, MPL or vehicle and exposed to room air or hyperoxia. We found that DPL and endotoxin both protected rats from lethal hyperoxia, but MPL alone was not protective. Even though MPL was not protective, DPL and MPL both increased endogenous release of tumor necrosis factor alpha early after injection (peak DPL level, 3619 +/- 1500 pg/ml, peak MPL level, 4038 +/- 500 pg/ml). Protection in both the endotoxin- and DPL-treated animals was associated with increases in lung antioxidant enzyme activities. We concluded that DPL protect rats from hyperoxia but that MPL is not protective in spite of its immunostimulatory and mitogenic effects.     

Multiple-organ effect of normobaric hyperoxia in neonatal rats

PURPOSE: Prolonged exposure to normobaric hyperoxia (NH) is associated with blood leukocyte activation and sequestration in the lung. Whether NH-induced leukocyte activation and sequestration can affect extrapulmonary organs or blood cellular profile has not been systematically investigated. We studied simultaneous changes in blood cellular profile and pulmonary, renal, and intestinal histology during NH and after return to air breathing ("weaning"). MATERIALS AND METHODS: One-day-old rats were exposed to 2 to 4 days of NH (FiO2 >0.98) or normoxia (FiO2 = 0.21), with or without weaning. Pups were then euthanized and 100 microL of blood was collected (cardiac puncture) for differential white blood cells analysis (n = 12 per group). The lungs, a piece of distal ileum, and the left kidney were removed for histologic evaluation. RESULTS: Both NH and weaning generated significant increases in blood neutrophil count, whereas lymphocyte population was significantly increased only after weaning (P < .05; analysis of variance with Bonferroni correction for multiple comparisons). Normobaric hyperoxia created mild increases in the renal tubular necrosis, dilation, regeneration, and interstitial inflammation. A significant increase in the intestinal serosal and submucosal vasodialation and vascularization occurred 1 day after weaning from 4 days of NH (P < .001). These extrapulmonary events coincided with the development of histologic manifestations of pulmonary oxygen toxicity. CONCLUSIONS: Development of pulmonary oxygen toxicity in neonatal rats is associated with significant changes in differential leukocyte counts and histologic alterations in the kidney and ileum. We speculate that activation of circulating leukocytes and/or direct effect of NH may affect certain peripheral organs independently from the NH-induced pulmonary pathology.     

促红细胞生成素衍生物抗糖尿病大鼠心肌纤维化的作用

目的探讨氨甲酰促红细胞生成素(CEPO)对实验性糖尿病大鼠心脏的保护作用。方法高脂高糖饲料喂养联合链脲佐菌素建立糖尿病大鼠模型,建模成功后按处理方式不同分为:空白组(A组),糖尿病模型组(B组),糖尿病+CEPO低剂量组(C组),糖尿病+CEPO中剂量组(D组),糖尿病+CEPO高剂量组(E组),重组人促红细胞生成素(rh EPO)+糖尿病组(F组)。利用HE染色、Masson染色观察大鼠心肌形态学变化。免疫组化方法检测心肌转化生长因子(TGF)-β1、结缔组织生子因子(CTGF)蛋白表达情况。应用SPSS 13.0统计软件包进行数据处理,多组间比较采用单因素方差分析,组间两两比较采用SNK检验。结果糖尿病大鼠心肌内胶原组织明显增多,TGF-β1、CTGF蛋白表达增多,与对照组比较差异有统计学意义(TGF-β1:9.84±1.33 vs.4.91±1.16;CTGF:9.67±1.52 vs.3.44±1.34;P<0.05),CEPO可使心肌内胶原组织减少,TGF-β1、CTGF蛋白表达减少,并且剂量越大疗效越明显(TGF-β1:6.38±1.26;CTGF:6.09±1.66,P<0.05)。结论 CEPO可改善糖尿病大鼠心肌纤维化程度,其疗效具有剂量依赖性。     

Vitamin A protects the small intestine from methotrexate-induced damage in rats

A protective effect of vitamin A (VA) against cytotoxic antitumor drug-induced damage of rat small intestine was found. Oral administration of methotrexate (MTX) for the small intestinal mucosa of rats resulted in a severe histological change, whereas rats coadministered VA with MTX showed a histological status similar to that of control rats. The p.o. administration of MTX led to a decrease in the amounts of membrane proteins and lipids in rat small intestine and its brush border membrane. When administered p.o. with VA, this decrease failed to occur. The brush border membrane of MTX plus VA-treated rats, when monitored by the fluorescence of cationic safranin O and anionic 8-anilino-1-naphthalenesulfonic acid, was found to resemble that from control rats rather than that from MTX-treated rats. The in vitro permeation of MTX in the small intestine of MTX plus VA-treated rats was enhanced, in contrast with the decrease noted for MTX-treated rats. However, that of untreated rats was not affected by the presence of VA. Thus, VA is unlikely to affect the transport process of MTX directly. When administered p.o. with VA, MTX was absorbed effectively to the same or a slightly greater extent than when administered by itself. Consequently, it has been shown histologically, biochemically, physicochemically and physiologically that VA protects the small intestine from the damage induced by MTX.     

Intrinsic vasodilation protects Wistar Kyoto rats from progressive glomerulosclerosis after unilateral nephrectomy

Genetically determined differences in functional and structural determinants that govern the development of progressive glomerulosclerosis (GS) were studied in aging sham-operated or unilaterally nephrectomized male rats of two strains. Wistar rats showed an increase of proteinuria and GS with age, which was enhanced by unilateral nephrectomy (UN). In contrast, intact and UN Wistar Kyoto rats did not show an increase of proteinuria with age and 7 months after UN, no GS was seen in these rats. Systemic blood pressure was comparable in both strains and was not affected by UN. Functional studies in a separate group of rats 1 month after UN showed an identical increase in glomerular filtration rate in both strains as compared with sham-operated controls. The Wistar rats did not show an effect of UN on renal plasma flow, and consequently, there was an increase in filtration fraction, in contrast to Wistar Kyoto rats, which showed an increase in renal plasma flow with an unchanged filtration fraction. Glomerular volume was increased in both strains at 1 month and 7 months after UN. Mesangial expansion was not observed at 1 month after UN in either strain, which indicates that this is not a decisive factor in the development of GS. These data indicate that the genetically determined susceptibility to the development of GS in these two rat strains may be related to the degree of vasoconstriction, whereas glomerular volume expansion per se does not lead to GS but can well be a consequence of hyperfiltration. These studies are concordant with previous studies that revealed the role of hemodynamics in the pathogenesis of GS irrespective of glomerular expansion.     

Inhibition of pseudocholinesterase activity protects from cocaine-induced cardiorespiratory toxicity in rats.

We studied the effect of inhibition of pseudocholinesterase by a specific pseudocholinesterase inhibitor, tetraisopropyl pyrophosphoramide (ISO-OMPA) on the cardiorespiratory toxicity of intravenously injected cocaine in rats. Group 1 rats received ISO-OMPA subcutaneously, whereas group 2 rats received saline placebo subcutaneously. Thirty minutes later, rats were anesthetized with 40 mg/kg of sodium pentobarbital intraperitoneally and were then given 10 mg/kg (least toxic dose) cocaine intravenously. Thirty minutes after the first injection of cocaine, about half of the rats that survived from each group were given 12 mg/kg cocaine (low toxic dose) intravenously, and the other half was given 13.5 mg/kg cocaine (high toxic dose) intravenously. Five minutes after each injection, rats were classified as either survivors or fatalities. In group 1 (ISO-OMPA treated), five of 29 (17%) rats that received 10 mg/kg cocaine, two of 11 (19%) that received 12 mg/kg cocaine, and three of 13 (24%) that received 13.5 mg/kg cocaine died of cardiorespiratory toxicity. In group 2 (saline treated), two of 29 (7%) that received 10 mg/kg cocaine, six of 12 (50%) that received 12 mg/kg cocaine, and 10 of 15 (67%) that received 13.5 mg/kg cocaine died of cardiorespiratory toxicity (p less than 0.03). Pseudocholinesterase activity (mean +/- SEM) of groups 1 and 2 were 0.6 +/- 0.2 and 7.3 +/- 0.7 units, respectively (p less than 0.01). Our results show that rats with lower pseudocholinesterase activity had lower fatality rates than rats with higher pseudocholinesterase activity.     

Saturated hydrogen saline protects rats from acute lung injury induced by paraquat

BACKGROUND: Paraquat (PQ) intoxication causes lung oxidative stress damage. Saturated hydrogen saline, a newly explored antioxidant, has been documented to play a powerful antioxidant role in preventing oxidative stress damage. This study aimed to investigate the protective effects and the possible mechanisms of intoxication on rats with acute lung injury (ALI) caused by paraquat poisoning.METHODS: Thirty PQ poisoned rats were randomly divided into a PQ intoxication group (intoxication group), a saturated hydrogen saline intervention group (intervention group), and a control group, with 10 rats in each group. The first two groups accepted an intragastric administration of PQ at a dose of 50 mg/kg for every single rat, and the control group was fed with a same volume of normal saline. Five mL/kg of saturated hydrogen saline was given to the intervention group three times a day by peritoneal injection for three days after intoxication. Arterial blood gas was detected on the third day. The rats were executed and their lungs were taken for measurement of wet dry weight ratio, homogenate malondialdehyde (MDA), and 8-hydroxy-2'-deoxyguanosine (8-OhdG). Histological changes of the lungs were also observed.RESULTS: Compared with the control group, the intoxication group had more serious hypoxemia, greater wet/dry weight ratio, higher MDA level, higher expression of 8-OhdG and more severe lung damage (P<0.01 or P<0.05). However, after intervention with saturated hydrogen saline, poisoned animals turned to have lighter hypoxemia, smaller wet/dry weight ratio, lower MDA level, lower expression of 8-OhdG, and milder lung damage (P<0.01 or P<0.05).CONCLUSIONS: Saturated hydrogen saline is effective in preventing acute lung injury caused by PQ. Possibly, it can neutralize toxic oxygen radicals selectively and alleviate the oxidative stress injury induced by PQ.     

Thymoquinone protects against cardiac damage from doxorubicin-induced heart failure in Sprague-Dawley rats

Heart failure is a complex end stage result of various cardiovascular diseases, and has a poor prognosis. The mechanisms for the development and progression of heart failure have always been an important topic in cardiovascular research, and previous studies have shown that thymoquinone (TQ) protects against cardiotoxicity and cardiac damage. The aim of this study was to investigate the possible protective effects of thymoquinone against cardiac damage in doxorubicin (DOX)-induced heart failure in Sprague-Dawley Rats (SDR). Forty-five male SDR were randomly divided into three groups and administered different treatment regimens for 8 weeks. Left ventricular fractional shortening (LVFS) and ejection fraction (LVEF) were higher in the DOX + TQ group than those in the DOX group. Significant pathophysiology changes (HE and Masson staining) were observed in rats of the DOX group compared to those of the DOX + TQ group. The addition of Thymoquinone inhibited DOX-induced cardiac fibrosis (TGF-β, Smad3, collagen I, collagen III, and α-SMA) and apoptosis (P53, bcl-2, caspase-3, caspase-9, and BAX) in SDR, indicating that thymoquinone may be a potential therapeutic target for cardiac damage caused by DOX-induced heart failure.

Heart failure is a complex end stage result of various cardiovascular diseases, and has a poor prognosis.     

高浓度氧对未成年大鼠肺部炎症反应的影响

目的 探讨高浓度氧对未成年大鼠肺部炎症反应的影响.方法 将40只出生21 d的SD大鼠按随机数字表法分为空气对照组及高氧暴露12、24、48、72 h组,每组8只,分别将大鼠置于空气和常压高氧箱(氧含量达92%～94%)中.于相应时间点采用放血法处死大鼠后取肺组织,并行支气管肺泡灌洗.采用硫代巴比妥酸法和比色法分别测定肺组织丙二醛(MDA)含量及髓过氧化物酶(MPO)活性;采用酶联免疫吸附法(ELISA)检测支气管肺泡灌洗液(BALF)中肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)和IL-10含量;观察肺组织病理改变,并进行肺损伤评分.结果 与空气对照组比较,高氧暴露12 h肺组织MDA含量(mmol/g)即显著升高(2.24±0.43比1.57±0.31),MPO活性(U/g)于高氧暴露24 h显著升高(1.24±0.25比0.69±0.22),并均随高氧暴露时间延长逐渐增加(P<0.05或P<0.01).BALF中TNF-α、IL-6和IL-10含量于高氧暴露24 h时较空气对照组显著增加[TNF-α(ng/L):135.2±44.0比94.5±22.3,IL-6(ng/L):73.1±14.2比55.7±17.3,IL-10(ng/L):67.9±21.7比48.2±7.6,P<0.05或P<0.01];但高氧暴露48 h时较24 h时显著降低(48 h时BALF中TNF-α、IL-6、IL-10分别为105.4±17.0,54.3±17.4,50.9±6.9,均P<0.05).高氧暴露12 h时肺损伤评分(分)即较空气对照组显著升高(4.5±1.4比1.3±0.5),并随高氧暴露时间延长进一步升高(P<0.05或P<0.01).结论 高浓度氧可引起未成年大鼠肺部炎症损伤;炎症细胞因子的出现高峰均在高氧暴露24 h.     

N-乙酰半胱氨酸对急性胰腺炎模型大鼠的保护作用

背景：急性胰腺炎是由胰腺腺泡细胞损伤介导的常见炎性疾病,白细胞浸润是其主要的发病特征。近来发现N-乙酰半胱氨酸能够控制白细胞游走并在一些严重的炎症疾病中发挥调节炎症反应的作用。
　　目的：观察N-乙酰半胱氨酸在体内对牛黄胆酸盐诱导的急性胰腺炎大鼠模型的保护作用。
　　方法：90只SD大鼠随机等分为正常对照组、急性胰腺炎组和N-乙酰半胱氨酸组,后2组以十二指肠大乳头逆行注射牛黄胆酸盐制备急性大鼠胰腺炎模型。N-乙酰半胱氨酸组大鼠由尾静脉给予N-乙酰半胱氨酸治疗。结果与结论：急性胰腺炎模型诱导后大鼠血浆淀粉酶活性较正常对照组大鼠显著升高(P<0.05)。急性胰腺炎组白细胞介素1β,6,10和肿瘤坏死因子α表达水平明显高于正常对照组(P<0.05)。免疫荧光化学显示N-乙酰半胱氨酸主要表达在胰岛细胞上,急性胰腺炎组织 N-乙酰半胱氨酸的表达从 mRNA 水平到蛋白水平都明显低于正常组织。N-乙酰半胱氨酸治疗显著降低了大鼠血清淀粉酶水平,髓过氧化物酶活性以及促炎性细胞因子产物生产和胰腺及肺组织损伤,但N-乙酰半胱氨酸治疗并没有明显抑制胰腺组织核因子κB的激活。提示N-乙酰半胱氨酸能改善急性胰腺炎大鼠胰腺和肺脏的组织损伤,并发挥抗炎症的作用。     

Adenovirus-mediated atrial natriuretic protein expression in the lung protects rats from hypoxia-induced pulmonary hypertension

Endogenous as well as exogenous atrial natriuretic peptide (ANP) attenuates the development of chronic hypoxic pulmonary hypertension (CHPH) in rats. We built a recombinant adenovirus type 5 containing ANP cDNA under the control of the Rous sarcoma virus long terminal repeat (Ad.ANP). The efficiency of this vector in delivering the ANP gene was first examined in rat primary cultures of pulmonary vessel smooth muscle cells (SMCs) in comparison with Ad.beta GAL. Conditioned medium collected from Ad.ANP-infected cells (1000 TCID(50)/cell) contained 5 x 10(9) M immunoreactive ANP and elicited relaxation of isolated rat pulmonary arteries preconstricted with phenylepinephrine. To examine the effects of adenovirus-mediated ANP expression in the CHPH rat lung, Ad.ANP or Ad.beta GAL was administered via the tracheal route. Immunoreactive ANP was detected in bronchoalveolar fluid as early as 4 days and until 10-17 days after Ad.ANP administration (5 x 10(8) TCID(50)). Lung ANP immunostaining was mainly localized in bronchial and alveolar epithelial cells. As compared with Ad.beta GAL-treated controls, rats given Ad.ANP (5 x 10(8) TCID(50)) on the day before a 2-week exposure to hypoxia (10% O(2)) had lower values for pulmonary artery pressure (32.1 +/- 1.93 vs. 35.5 +/- 2 mmHg, p < 0.01) and Fulton's index (0.52 +/- 0.089 vs. 0.67 +/- 0.12, p < 0.001) and less severe right ventricular hypertrophy and distal vessel muscularization. These results suggest that induction of ANP expression in the lung may hold promise in the treatment of pulmonary hypertension.     

Dose-related effects of hyperoxia on the lung inflammatory response in septic rats

We evaluated the effects of hyperoxia on pulmonary inflammatory changes in sepsis induced by cecal ligation and puncture (CLP) in rats. Seven groups were studied: sham-operated rats breathing air for 20 or 48 h; CLP breathing air for 20 or 48 h; and CLP + 100% oxygen for 20 h, or 70% oxygen for 48 h, or 100% oxygen intermittently (6 h/d) for 48 h. Video microscopy was used to monitor lung macromolecular leak, microvascular flow velocity, and shear rates, and lung morphometry was used for leukocyte infiltration and solid tissue area. Cell counts, tumor necrosis factor α, and nitrites were determined in peripheral blood and lung lavage fluid. Expression of adhesion molecules in blood leukocytes was evaluated by flow cytometry. Cecal ligation and puncture induced inflammation manifested in leukopenia, left shift, thrombocytopenia, increased expression of L selectin and CD11, increased serum and lavage fluid tumor necrosis factor α and leukocytes, and increased lung tissue area, macromolecular leak, and sequestration of leukocytes. Inhalation of 100% oxygen for 20 h increased nitrites (P < 0.01) and decreased leukocyte count in lavage fluid (P < 0.05) and attenuated lung macromolecular leak and changes in solid tissue area (P < 0.01). Inhalation of 70% oxygen (48 h) attenuated expression of adhesion molecules (P < 0.001) but failed to attenuate markers of lung inflammation. In contrast, intermittent 100% oxygen exerted favorable effects on markers of inflammation, attenuated leukocyte expression of L selectin and CD11 (P < 0.01), decreased pulmonary sequestration of leukocytes (P < 0.001), and ameliorated changes in macromolecular leak (P < 0.01) and lung solid tissue area (P < 0.05). Our data support the beneficial effects of safe subtoxic regimens of normobaric hyperoxia on the systemic and pulmonary inflammatory response following CLP.     

Tolerance of rats to hyperoxia. Lung antioxidant enzyme gene expression.

Tolerance to hyperoxia usually requires an increase of lung antioxidant enzyme (AOE) activity. We used rats with different degrees of tolerance to > 95% O2 to evaluate the importance of individual AOEs for tolerance; we also explored the regulation of AOE gene expression. During exposure of adult rats to > 95% O2, lung manganese superoxide dismutase (MnSOD) activity fell approximately 50% despite a threefold increase of MnSOD mRNA concentration; addition of a reducing agent to lung extracts from O2-exposed rats partially restored MnSOD activity. Endotoxin induced tolerance to O2 (a) without elevating Cu,Zn superoxide dismutase activity, (b) with increases of catalase and glutathione peroxidase (GP) activity of the same magnitude as occurred in O2-saline rats, but (c) with MnSOD activity 1.5-1.9-fold higher than in air-saline rats and 1.4-3.6-fold higher than in O2-saline rats. Endotoxin elevated the concentration of MnSOD and GP mRNAs without increasing their stability. O2 elevated MnSOD mRNA concentration, and increased its stability. O2 plus endotoxin increased the concentration and stability of MnSOD, catalase, and GP mRNAs. These data suggest that in adult rats tolerance to hyperoxia requires increased MnSOD activity; the data show gene expression and regulation vary among the AOEs, and that increased stability of the AOEs' mRNAs plays an important role in AOE gene expression and in tolerance to hyperoxia.     

DNA vaccination with CD25 protects rats from adjuvant arthritis and induces an antiergotypic response

Ab's to the alpha-chain of the IL-2 receptor (anti-CD25) are used clinically to achieve immunosuppression. Here we investigated the effects of DNA vaccination with the whole CD25 gene on the induction of rat adjuvant arthritis. The DNA vaccine protected the rats and led to a shift in the cytokine profile of T cells responding to disease target antigens from Th1 to Th2. The mechanism of protection was found to involve the induction of an antiergotypic response, rather than the induction of anti-CD25 Ab's. Antiergotypic T cells respond to activation molecules, ergotopes, expressed on syngeneic activated, but not resting, T cells. CD25-derived peptides function as ergotopes that can be recognized by the antiergotypic T cells. Antiergotypic T cells taken from control sick rats did not proliferate against activated T cells and secreted mainly IFN-gamma. In contrast, antiergotypic cells from CD25-DNA-protected rats proliferated against activated T cells and secreted mainly IL-10. Protective antiergotypic T cells were found in both the CD4+ and CD8+ populations and expressed alpha/beta or gamma/delta T cell receptors. Antiergotypic alpha/beta T cells were MHC restricted, while gamma/delta T cells were MHC independent. Thus, CD25 DNA vaccination may induce protection from autoimmunity by inducing a cytokine shift in both the antiergotypic response and the response to the antigens targeted in the disease.     

PEP-1-SOD1 protects brain from ischemic insult following asphyxial cardiac arrest in rats

Aim of the study

Reperfusion following cerebral ischemia leads to excessive production of reactive oxygen species (ROS) and consumption of endogenous antioxidants. Antioxidant enzymes are considered to have beneficial effects against various diseases mediated by ROS. Copper, zinc-superoxide dismutase (SOD1) is one of the major defensive mechanisms by which cells counteract the deleterious effects of ROS after ischemia. However, exogenous SOD1 can not be delivered into living cells because of the poor permeability and selectivity of the cell membrane, thus its application for protecting cells/tissues from oxidative stress damage is greatly limited.

Methods

The purified SOD1 or PEP-1-SOD1 fusion proteins were injected into rats via their tail veins, the transduction ability of PEP-1-SOD1 was examined with immunofluorescent staining and SOD1 activity was measured. Moreover, we determined whether or not PEP-1-SOD1 can protect brain from ischemic injury in an experimental asphyxial cardiac arrest rat model through histopathologic analysis, evaluating the levels of malondialdehyde (MDA), S100β and neuron specific enolase (NSE).

Results

SOD1 protein was observed in PEP-1-SOD1-treated animals and SOD1 activity was significantly increased. However, SOD1 protein was not detected in SOD1-treated animals. The transduced PEP-1-SOD1 significantly attenuated cerebral ischemia-reperfusion damage, inhibited ischemia-induced lipid peroxidation, and protected neurons in hippocampus from the damage induced by transient global ischemic insults.

Conclusions

PEP-1-SOD1 fusion protein can be transduced into the neurons in vivo and protect the neurons from the transient global ischemia-induced damage, suggesting PEP-1-SOD1 may be used for the treatment of oxidative stress-associated disorders such as transient global cerebral ischemia.     

Hypothermia protects against endotoxin-induced acute lung injury in rats

OBJECTIVE: Hypothermia in humans and animals is known to decrease the number and function of circulating neutrophils. Because an activation of circulating neutrophils and their sequestration into the lung are important pathogenetic phenomena in endotoxin-associated lung injury, we conjectured that hypothermia could prevent this type of lung injury. DESIGN AND SETTING: Animal study at a university-affiliated research institute. SUBJECTS: Thirty-six Sprague-Dawley rats. INTERVENTIONS: After anesthesia, the rats were randomly assigned to normothermia (37 degrees C, rectal temperature) or hypothermia (27 degrees C), which was induced by surface cooling. After 1 h of stable temperature, the rats were administered intratracheal doses of lipopolysaccharide (LPS; 3 mg/kg) (normothermia-LPS; hypothermia-LPS) or an equivalent volume of normal saline (normothermia-saline; hypothermia-saline). The rectal temperature was maintained within +/-1 degrees C of the target temperature for 6 h after the intratracheal treatment. MEASUREMENTS AND RESULTS: Compared with the normothermia-LPS group, the neutrophil count in bronchoalveolar lavage (BAL) fluid (p=0.002) and the myeloperoxidase activity of lung tissues (p=0.002) of the hypothermia-LPS group were both lower. Compared with the normothermia-LPS group, the BAL interleukin-1beta level of the hypothermia-LPS group was lower (p<0.001), whereas the BAL interleukin-10 level of the hypothermia-LPS group was higher (p=0.026). Compared with the normothermia-LPS group, the histologic scores for acute lung injury of the hypothermia-LPS group were lower (p=0.007). CONCLUSIONS: Hypothermia pretreatment decreased the pulmonary sequestration of neutrophils, induced a favorable balance between pro- and anti-inflammatory cytokines, and attenuated histologic injury in endotoxin-challenged rats.     

Sesame oil protects against lipopolysaccharide-stimulated oxidative stress in rats

OBJECTIVE: The aim of this study was to determine the effects and the defense mechanisms of sesame oil on lipopolysaccharide-induced oxidative stress in rats. DESIGN: Laboratory in vivo study of the effect of sesame oil on lipid peroxide, superoxide anion, superoxide dismutase, catalase, glutathione, and nitrite concentrations. To assess the effect of sesame oil on hepatic function, we determined serum aspartate aminotransferase, total bilirubin, and liver histology. SETTING: University laboratory. SUBJECTS: Male SPF Wistar rats. INTERVENTIONS: Blood testing, administration of oils, and liver biopsies. MEASUREMENTS AND MAIN RESULTS: Oxidative stress induced by lipopolysaccharide (5 mg/kg, intraperitoneally) was assessed by determination of lipid peroxidation. Sesame oil was given orally immediately after lipopolysaccharide administration, and lipid peroxidation concentrations were determined. The reactive oxygen species superoxide anion was measured by chemiluminescence analyzer. The enzyme activities of superoxide dismutase and catalase and the concentrations of glutathione and nitrite also were determined. Hepatic injury was evaluated by determining the concentrations of serum aspartate aminotransferase and total bilirubin and by liver histologic examination. Sesame oil significantly reduced lipid peroxidation but failed to affect nitrite concentrations in lipopolysaccharide-treated rats. Superoxide anion counts were decreased, and glutathione, but not superoxide dismutase or catalase, was increased in sesame oil-treated groups with lipopolysaccharide-induced oxidative stress. Only sesame oil-treated groups, but not corn oil- or mineral oil-treated groups, showed attenuated hepatic disorder induced by lipopolysaccharide. In addition, sesame oil given 6 hrs after lipopolysaccharide also attenuated lipid peroxidation and hepatic disorder. Furthermore, sesame oil given immediately or 6 hrs after lipopolysaccharide administration significantly reduced morphologic changes induced by lipopolysaccharide. CONCLUSION: A single dose of sesame oil may attenuate oxidative stress and subsequently relieve hepatic disorder in endotoxemic rats.