Escin attenuates acute lung injury induced by endotoxin in mice

Endotoxin causes multiple organ dysfunctions, including acute lung injury (ALI). The current therapeutic strategies for endotoxemia are designed to neutralize one or more of the inflammatory mediators. Accumulating experimental evidence suggests that escin exerts anti-inflammatory and antiedematous effects. The aim of this study was to evaluate the effect of escin on ALI induced by endotoxin in mice. ALI was induced by injection of lipopolysaccharide (LPS) intravenously. The mice were given dexamethasone or escin before injection of LPS. The mortality rate was recorded. Tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β) and nitric oxide (NO) were measured. Pulmonary superoxide dismutase (SOD), glutathione peroxidase (GPx) activity, glutathione (GSH), malondialdehyde (MDA) contents, and myeloperoxidase (MPO) activity were also determined. The expression of glucocorticoid receptor (GR) level was detected by Western blotting. Pretreatment with escin could decrease the mortality rate, attenuate lung injury resulted from LPS, down-regulate the level of the inflammation mediators, including NO, TNF-α, and IL-1β, enhance the endogenous antioxidant capacity, and up-regulating the GR expression in lung. The results suggest that escin may have potent protective effect on the LPS-induced ALI by inhibiting of the inflammatory response, and its mechanism involves in up-regulating the GR and enhancing the endogenous antioxidant capacity.     

Recombinant fibronectin polypeptide antagonizes hepatic failure induced by endotoxin in mice

INTRODUCTION Fibronectin (FN) is known to be a large multifunc-tional glycoprotein with binding sites for many sub-stances and integrin cell-surface receptors on a varietyof cells including fibroblasts, phagocytes and bacte-ria[1]. Extensive in vitro functional analyses indicatethat FN modulates cell proliferation, migration and sur-vival[2]. FN interacts with cells in cell-binding domainswith RGDS sequence, which is located in the 10th typeIII repeats of FN, the synergy seque…     

GABA(A) alpha 1 subunit knock-out mice do not show a hyperlocomotor response following amphetamine or cocaine treatment

The GABA(A) receptor system provides the major inhibitory control in the CNS, with the alpha 1 beta 2 gamma 2 subunit combination being the most abundant and widely distributed form of the receptor. The alpha1 subunit knock-out (alpha1 KO) mice had a surprisingly mild overt phenotype, despite having lost approximately 60% of all GABA(A) receptors. The alpha1 KO mice had normal spontaneous locomotor activity, but were more sensitive to the sedating/ataxic effects of diazepam than wildtype (WT) mice. Pharmacological modulation of dopamine and N-methyl-D-aspartate (NMDA) receptors also produced altered responses in alpha1 KO mice compared with WT mice. As expected, the NMDA receptor antagonist MK801, amphetamine and cocaine increased locomotor activity in WT mice. Although MK801 increased locomotor activity in alpha1 KO mice, amphetamine and cocaine induced stereotypy not hyperlocomotion. Binding studies showed no gross changes in the total number of D1, D2 or NMDA receptors. Furthermore, pre-pulse inhibition of acoustic startle and the effects of cocaine in conditioned place preference were similar in both alpha1 KO and WT mice, indicating selective rather that global changes in response to dopaminergic agents. These data demonstrate subtle changes in behaviours mediated by neurotransmitters other than GABA in alpha1 KO mice and suggest that compensation may have occurred beyond the GABAergic system.     

Locomotor depression in mice by norcocaine does not involve central alpha 2-adrenergic or presynaptic dopamine receptors

The inhibition of spontaneous locomotor behavior of mice by norcocaine was antagonized neither by the adrenoceptor antagonists yohimbine and phentolamine, nor by the neuroleptics haloperidol and spiperone, at low doses aimed at presynaptic dopamine receptors. In contrast, the antagonists were effective in reducing the hypomotility induced by clonidine and apomorphine, respectively. These results make it unlikely that central alpha 2-adrenergic or presynaptic dopamine receptors are involved in the hypomotive effect of norcocaine.     

Inhaled activated protein C attenuates lung injury induced by aerosolized endotoxin in mice

The serine protease activated protein C (APC) possesses prominent anticoagulant and anti-inflammatory actions. In this study, we investigated the effect of inhaled recombinant human (rh) APC in a murine lung injury model. Animals inhaled 10 mg of Pseudomonas lipopolysaccharide (LPS) in 3 mL normal saline (NS); 30 min prior to LPS, mice were pretreated with inhaled rhAPC (4 mg/3 mL NS; APC+LPS group) or NS (LPS group). A control animal group inhaled vehicle (NS) twice. 24 h later, total cells and cell-types, protein content, and the cytokines tumor necrosis factor-alpha, interleukin (IL)-6, macrophage inflammatory protein-1alpha, and mouse keratinocyte-derived chemokine (a homolog of human IL-8) were estimated in bronchoalveolar lavage fluid (BALF). Lung pathology given as total histology score (THS), wet/dry lung weight ratios, and lung vascular cell adhesion molecule (VCAM)-1 expression were additionally assessed. rhAPC inhalation attenuated the aerosolized LPS-induced increases of: total cells, neutrophils and macrophages in BALF, lung tissue VCAM-1 protein levels, and THS. Total protein levels and cytokines in BALF, and wet/dry weight ratios were increased in the LPS group, but rhAPC pretreatment did not significantly alter the LPS-induced responses. In conclusion, in this murine septic model of lung injury, inhaled rhAPC appears to attenuate lung inflammation, without reversing the observed increases in lung permeability and BALF cytokines. This effect may be associated with leukocyte trafficking modifications, related, at least in part, to VCAM-1 reduction.     

Time course of IL-6 and TNF alpha release during endotoxin-induced endotoxin tolerance in rats.

Development of endotoxin tolerance in rats induced by repeated application of low dosages of endotoxin is associated with repeatable IL-6 formation, reversible drop in white blood cells, pronounced consumption of platelets, gradual formation of alpha 2M as an example of acute phase proteins, and flattening TNF alpha formation. In the status of full tolerance the TNF alpha release is completely eliminated. Inhibition of TNF alpha biosynthesis and induction of acute phase protein formation by IL-6 are discussed as possible factors in the development of endotoxin tolerance.     

Distribution of TNF endogenously induced by various immunopotentiators and Lactobacillus casei in mice.

Intravenous administration of heat-killed Lactobacillus casei YIT 9018 (LC) elicited endogenous cytotoxic factor (CF) production in ICR mice, peaking in serum after 2 h and declining gradually to basal level at 23 h. The endogenous CF production was significantly enhanced by priming with high molecular-weight lignins and glucans, but not by phenylpropenoid precursors or partially hydrolyzed products of glucans. The extent of stimulation of CF production by these priming agents was positively related to that of tumor necrosis factor (TNF) production, as judged by enzyme-linked immunosorbent assay. Endogenously produced TNF was concentrated more in liver, lung and intestine, as well as in serum, than in other organs. Histochemical examination revealed a significant increase in the number and swelling of Kupffer cells and sinusoidal endothelium in the liver of the treated mice.     

Tegumental alterations in Schistosoma mansoni worms induced by treatment of infected mice with naproxen pre- and/or post-infection.

Schistosoma mansoni infected mice were treated with naproxen (CAS 22204-53-1) in a dose of 3-4 mg/kg body weight. Treatment was conducted for 7 days before and/or 28 days post infection. Adult worms, developed 7 weeks post infection, were studied by electron microscopy. In both groups, the dorsal surface of the male worms was much more affected by the drug than that of female ones. The most significant morphological degeneration was the change in the aspect and the form of tubercles. Moreover, shrinkage and loss of spines from the ventral surface were also observed. A small portion of the posterior end of female worms showed loss of spines. However, in the first group given naproxen 7 days before infection, the level and extent of changes increased particularly in male worms. There was pronounced oedema, swelling, wrinkling with constriction and collapse of sensory bulbs.     

Brain enzyme and clinical alterations induced in rats and mice by nitroaliphatic toxicants

The effects of a single subcutaneous (s.c.) injection of the nitroaliphatic toxicants 3-nitropropanol (NPOH) and 3-nitropropionic acid (NPA) dissolved in physiological saline solution were studied in mice and rats, respectively. Clinical signs observed in both NPOH-treated mice and NPA-treated rats included depression, abnormal motor activity, and recumbency. Succinate dehydrogenase (SDH) activity, demonstrated histochemically in frozen brain sections, was markedly reduced in intoxicated mice and rats. The SDH activity of mitochondrial preparations from brains of intoxicated mice and rats was diminished to 18-24% of control values, although the activity of another mitochondrial flavoprotein enzyme, alpha-glycerophosphate dehydrogenase (alpha-GPDH), was not altered.     

Immunological and neurobiochemical alterations induced by repeated oral exposure of phenol in mice

Phenol, a major metabolite of benzene, is a potentially immunotoxic and neurotoxic substance of environmental significance. Male CD-1 mice were continuously exposed to 0, 4.7, 19.5, and 95.2 mg phenol/l in drinking water for 4 weeks. Various immune functions were evaluated and levels of selected neurotransmitters and metabolites measured in discrete brain regions. The doses of phenol did not produce any overt clinical signs of toxicity; peripheral red blood cell counts and hematocrits decreased. A dose of 95.2 mg/l suppressed the stimulation of cultured splenic lymphocytes by lipopolysaccharide, pokeweed mitogen, and phytohemagglutinin and the response in mixed lymphocyte cultures. The two high doses suppressed antibody production response to the T cell-dependent antigen (sheep erythrocytes), as determined by plaque-forming cells, and serum antibody levels. Mice treated with phenol had lower levels of neurotransmitters in several brain regions. In the hypothalamus, a major norepinephrine-containing compartment, the concentrations of norepinephrine significantly decreased by 29 and 40% in groups dosed with 19.5 and 95.2 mg/l, while dopamine concentrations decreased in the corpus striatum by 21, 26, and 35% at 4.7, 19.5 and 95.2 mg/l, respectively. Phenol also decreased 5-hydroxytryptamine in the hypothalamus, medulla oblongata, midbrain and corpus striatum. Levels of monoamine metabolites decreased in the hypothalamus (5-hydroxyindoleacetic acid), midbrain (vanillylmandelic acid), corpus striatum (vanillylmandelic acid and dihydroxyphenylacetic acid), cortex (vanillylmandelic acid), and cerebellum (dihydroxyphenylacetic acid).     

屈头鸡果对内毒素致小鼠急性肺损伤的保护作用

目的 研究屈头鸡果在内毒素致小鼠急性肺损伤中的作用及其机制.方法 将40只SPF级雄性BALB/c小鼠分为正常组、对照组、模型组和实验组,每组各10只.经鼻滴入20 mg·kg-1脂多糖构建内毒素致小鼠急性肺损伤模型,其中对照组和实验组分别灌胃屈头鸡果2.16 g·kg-1,正常组和模型组灌胃等量生理盐水.观察各组小鼠...     

Limitation of polymyxin B on suppression of endotoxin shock induced by Salmonella infection in mice

The protective effects of an antibiotic polymyxin B (PLB), having lipopolysaccharide (LPS)-binding activity, on infection-induced endotoxin shock in mice were investigated. Infection with 10(8) colony forming units of an attenuated Salmonella typhimurium aroA strain caused lethal endotoxin shock to ddY mice. Treatment with PLB 1 h post infection (p.i.) resulted in significant reduction of mortality and bacterial numbers in livers. In addition, treatment with PLB 1 h p.i. resulted in a transient increase at the early stage and gradual decline in plasma LPS levels. Although plasma levels of sCD14 and high mobility group box chromosomal protein-1 (HMGB-1) increased according with progression of infection, increases in plasma levels of sCD14 and HMGB-1 were downregulated by treatment with PLB 1 h p.i. However, the lethal shock was not blocked by treatment with anti-CD14 monoclonal antibody at 3 h and 6 h p.i. Interestingly, administration of PLB 6 h p.i. did not show any protective activities, indicating that a time window for effective PLB action is present.     

Cytogenetic and hematological alterations induced by acute oral exposure of imidacloprid in female mice

Imidacloprid (IMD), 1(6-chloro-3-pyridinyl)methyl)-N-nitro-2-imidazolidinimine, was administered in female mice to study in vivo cytogenetic (chromosomal aberrations (CAs) and micronucleus assay) and hematological effects. The acute oral LD₅₀ was determined to be 150?mg/kg bw in mice following OECD guidelines using AOT StatPgm425 software. The mice were administered orally with distilled water (negative control); mitomycin C (MMC), 1?mg/kg (positive control) and sub-lethal doses of 37.5 (low), 75.0 (medium) and 112.5 (high) mg/kg bw (25%, 50% and 75% of LD₅₀) of IMD to analyze CAs and hematological effects after 24?h, whereas micronucleus test (MT) after 48?h. The genotoxicity analysis revealed that selected test doses of IMD – medium and high doses – induced significantly mitotic inhibition (p?<?0.01), CAs (p?<?0.01) and at high dose micronucleus (MN) formation (p?<?0.05). Significant changes in red blood cell (RBC; p?<?0.01), hemoglobin (Hb; p?<?0.01) and erythrocyte sedimentation rate (ESR; p?<?0.001) were observed, except WBC in which significant increase (p?<?0.001) was observed. Present observation substantiates overall significant dose dependent genotoxic potential (p?<?0.05; r?=?0.98) of IMD. Precautions should be taken to minimize possible risk to exposed farmers of the state of Haryana (India) – an agrarian economy.     

Cyclooxygenase 1 is not essential for hypophagic responses to interleukin-1 and endotoxin in mice

Numerous studies have shown that the effects of interleukin-1 (IL-1) and endotoxin (LPS) on behavior are sensitive to cyclooxygenase (COX) inhibitors. However, neither the location of the COX involved nor the specific isoform, COX1 or COX2, is known. A previous study using selective COX1 and COX2 inhibitors did not provide an unequivocal answer. Therefore, we tested the response of sweetened milk ingestion to IL-1 and LPS in mice in which the COX1 or the COX2 gene was deleted (COX1ko and COX2ko). When IL-1beta was administered 90 min before the milk, COX1ko mice showed responses similar to those of normal mice. In contrast, COX2ko mice exhibited responses considerably less than normal, with some mice showing no response. Indomethacin pretreatment almost prevented the feeding responses to IL-1 in normal and COX1ko mice. The milk intake response to LPS in COX1ko mice was like that of normal mice. The results from COX1ko mice suggest that COX1 is not necessary for the decreased milk intake following IL-1 and LPS. The results from COX2ko mice are consistent with the involvement of COX2 in the IL-1-induced depression of milk intake, but other mechanisms may effect decreases in sweetened milk intake.     

Immunological and neurobiochemical alterations induced by repeated oral exposure of phenol in mice.

Phenol, a major metabolite of benzene, is a potentially immunotoxic and neurotoxic substance of environmental significance. Male CD-1 mice were continuously exposed to 0, 4.7, 19.5, and 95.2 mg phenol/l in drinking water for 4 weeks. Various immune functions were evaluated and levels of selected neurotransmitters and metabolites measured in discrete brain regions. The doses of phenol did not produce any overt clinical signs of toxicity; peripheral red blood cell counts and hematocrits decreased. A dose of 95.2 mg/l suppressed the stimulation of cultured splenic lymphocytes by lipopolysaccharide, pokeweed mitogen, and phytohemagglutinin and the response in mixed lymphocyte cultures. The two high doses suppressed antibody production response to the T cell-dependent antigen (sheep erythrocytes), as determined by plaque-forming cells, and serum antibody levels. Mice treated with phenol had lower levels of neurotransmitters in several brain regions. In the hypothalamus, a major norepinephrine-containing compartment, the concentrations of norepinephrine significantly decreased by 29 and 40% in groups dosed with 19.5 and 95.2 mg/l, while dopamine concentrations decreased in the corpus striatum by 21, 26, and 35% at 4.7, 19.5 and 95.2 mg/l, respectively. Phenol also decreased 5-hydroxytryptamine in the hypothalamus, medulla oblongata, midbrain and corpus striatum. Levels of monoamine metabolites decreased in the hypothalamus (5-hydroxyindoleacetic acid), midbrain (vanillylmandelic acid), corpus striatum (vanillylmandelic acid and dihydroxyphenylacetic acid), cortex (vanillylmandelic acid), and cerebellum (dihydroxyphenylacetic acid).     

ATP depletion does not account for apoptosis induced by inhibition of mitochondrial electron transport chain in human dopaminergic cells

As the mitochondrial electron transport chain (ETC) is necessary for life, its inhibition results in cell death. To date, ETC complex (I-IV) inhibitors (ETCIs) have been thought to induce ATP depletion, triggering cellular apoptosis. To clarify whether the depletion of intracellular ATP is relevant to apoptosis induced by ETCIs, we conducted comparative studies using oxidative phosphorylation inhibitors (OPIs), including a specific F(0)F(1)ATP synthase inhibitor oligomycin, an ionophore valinomycin and an uncoupler 2,4-dinitrophenol, as tools to deplete only ATP without influencing the ETC. In human dopaminergic SH-SY5Y cells, ETCIs (rotenone, thenoyltrifluoroacetone, antimycin A and potassium cyanide) depleted ATP and induced apoptosis. However, OPIs failed to induce apoptosis despite ATP being decreased to an extent comparable to that observed with ETCIs. Reactive oxygen species (ROS) production was augmented by ETCIs, but not by OPIs. Furthermore, ETCI-induced apoptosis was inhibited by the addition of an antioxidant N-acetylcysteine. Apoptosis was induced without ATP depletion by H(2)O(2) at a concentration that generated ROS at an amount comparable to that induced by ETCIs. Our findings demonstrate that ROS production is more relevant than ATP depletion to apoptosis induced by ETCIs.     

Polymorphisms of glutathione S-transferases M1 and T1 do not account for interindividual differences for smoking behavior

To identify whether the polymorphisms of glutathione S-transferase M1 (GSTM1) and GSTT1 genes predict a high-tended risk of using tobacco, the GSTM1 and GSTT1 genotypes of 369 Iranian males (254 nonsmokers and 115 smokers) and 314 Iranian females (245 nonsmokers and 69 smokers) were determined. The frequencies of GSTM1 (males: OR=0.98, 95% CI=0.62-1.57, P=.974; females: OR=1.34, 95% CI=0.75-2.39, P=.358) and GSTT1 (males: OR=1.25, 95% CI=0.76-2.04, P=.412; females: OR=0.84, 95% CI=0.46-1.51, P=.626) null genotypes were similar in nonsmokers and smokers. The risk of being a smoker was to be equally frequent in each combination of the genotypes. The present results revealed that there was no difference between smokers and nonsmokers for these two genetic polymorphisms.     

Estradiol and pesticide methoxychlor do not exhibit additivity or synergism in the reproductive tract of adult ovariectomized mice

The pesticide methoxychlor (MXC) is a DDT substitute that exhibits estrogenic activities in different animals. To determine whether there is synergism between purified MXC and a natural estrogen, ovariectomized adult mice received 3 daily intraperitoneal doses of either 2.5 or 25 ng estradiol-17beta or 0.125, 0.25, or 0.5 mg MXC administered separately or in combination. The mice were sacrificed on d 4. Reproductive tracts were excised, weighed, and one uterine horn was flushed with phosphate-buffered saline, with the fluid electrophoresed on a one-dimensional sodium dodecyl sulfate polyacrylamide gel to determine albumin content. The remaining uterine horn and vagina were prepared for histology and epithelial height measurements. Estradiol significantly increased reproductive-tract weights. Although both the vaginal and uterine epithelial heights increased in mice treated with combined chemicals when compared to controls, the organ histology did not show increased stimulation. Albumin content was significantly elevated only in the estradiol group. The present data do not suggest that either synergism or additive effects occurred between an estrogen and MXC in the reproductive tracts of ovariectomized adult mice. In fact, combining MXC with estradiol suggests inhibitory effects.     

Delayed myocardial protection induced by endotoxin does not involve kinin B(1)-receptors

Endotoxin is known to confer a delayed protection against myocardial infarction. Lipopolysaccharide (LPS) treatment also induces the de novo synthesis of kinin B(1)-receptors that are not present in normal conditions. The aim of this study was to evaluate whether LPS-induced B(1)-receptors are implicated in the reduction of infarct size brought about by LPS. Rabbits were submitted to a 30-min coronary artery occlusion and 3-h reperfusion sequence. Six groups were studied: pretreated or not (control animals) with LPS (5 microgram kg(-1) i.v.) 24 h earlier and treated 15 min before and throughout ischaemia - reperfusion with either the B(1)-antagonist R-715 (1 mg kg(-1) h(-1)), the B(1)-agonist Sar-[D-Phe(8)]-des-Arg(9)-bradykinin (15 microgram kg(-1) h(-1)) or vehicle (saline). Infarct size and area at risk were assessed by differential staining and planimetric analysis. The presence of B(1)-receptors in LPS-pretreated animals was confirmed by a decrease in mean arterial pressure in response to B(1) stimulation. LPS-pretreatment significantly reduced infarct size (6.4+/-1.7%, of area at risk vs 24.1+/-2.5% in control animals, P<0.05). This protection was not modified by B(1)-receptor antagonism (7.4+/-2.2%, NS) or stimulation (5.2+/-1.2%, NS). Neither antagonist nor agonist modified infarct size in control animals. In conclusion, these data suggest that LPS-induced myocardial protection in the rabbit is not related to concomitant de novo B(1)-receptor induction.     

Studies on the hepatotoxicity of galactosamine/endotoxin or galactosamine/TNF in the perfused mouse liver

Livers of male albino NMRI mice were perfused in situ at a flow rate of 3 ml/min/g liver in a non-recirculation system. The organs remained intact for at least 3 hr as assessed by release of lactate dehydrogenase (LDH) into the perfusate and by constant O2 consumption. The infusion of the following agents did not cause significant enzyme release or microscopically visible organ injuries: galactosamine (1.8 mg/ml), endotoxin (1 microgram/ml), murine recombinant tumor necrosis factor alpha (0.3 micrograms/ml/g) or combinations of them. In contrast, in vivo pretreatment of the animals with 700 mg/kg galactosamine + 5 micrograms/kg endotoxin, or 700 mg/kg galactosamine + 15 micrograms/kg tumor necrosis factor alpha (TNF) led to a massive LDH release into the perfusate. Infusion of uridine (0.67 mg/ml/g) into perfused livers from animals in vivo pretreated with either galactosamine/endotoxin or galactosamine/TNF, prevented LDH release and histologically visible liver injury. We conclude from these findings that in vivo pretreatment of the animals resulted in latent and reversible damage of the liver induced by extrahepatic factors which are prevented by intrahepatic events sensitive to uridine.