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Sample records for liver inducible nitric

  1. Nitric oxide in liver fibrosis: The role of inducible nitric oxide synthase.

    Science.gov (United States)

    Iwakiri, Yasuko

    2015-12-01

    The inducible form of nitric oxide synthase (iNOS) is expressed in hepatic cells in pathological conditions. Its induction is involved in the development of liver fibrosis, and thus iNOS could be a therapeutic target for liver fibrosis. This review summarizes the role of iNOS in liver fibrosis, focusing on 1) iNOS biology, 2) iNOS-expressing liver cells, 3) iNOS-related therapeutic strategies, and 4) future directions.

  2. Expression and activity of inducible nitric oxide synthase and endothelial nitric oxide synthase correlate with ethanol-induced liver injury

    Institute of Scientific and Technical Information of China (English)

    Guang-Jin Yuan; Xiao-Rong Zhou; Zuo-Jiong Gong; Pin Zhang; Xiao-Mei Sun; Shi-Hua Zheng

    2006-01-01

    AIM: To study the expression and activity of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) in rats with ethanol-induced liver injury and their relation with liver damage, activation of nuclear factor-KB (NF-кB) and tumor necrosis factor-α (TNF-α)expression in the liver.METHODS: Female Sprague-Dawley rats were given fish oil (0.5 mL) along with ethanol or isocaloric dextrose daily via gastrogavage for 4 or 6 wk. Liver injury was assessed using serum alanine aminotransferase (ALT)activity and pathological analysis. Liver malondialdehyde (MDA), nitric oxide contents, iNOS and eNOS activity were determined. NF-KB p65, iNOS, eNOS and TNF-αprotein or mRNA expression in the liver were detected by immunohistochemistry or reverse transcriptase-polymerase chain reaction (RT-PCR).RESULTS: Chronic ethanol gavage for 4 wk caused steatosis, inflammation and necrosis in the liver, and elevated serum ALT activity. Prolonged ethanol administration (6 wk) enhanced the liver damage. These responses were accompanied with increased lipid peroxidation, NO contents, iNOS activity and reduced eNOS activity. NF-кB p65, iNOS and TNF-α protein or mRNA expression were markedly induced after chronic ethanol gavage, whereas eNOS mRNA expression remained unchanged. The enhanced iNOS activity and expression were positively correlated with the liver damage, especially the necro-inflammation, activation of NF-кB, and TNF-α mRNA expression.CONCLUSION: iNOS expression and activity are induced in the liver after chronic ethanol exposure in rats, which are correlated with the liver damage, especially the necro-inflammation, activation of NF-KB and TNF-αexpression. eNOS activity is reduced, but its mRNA expression is not affected.

  3. Hypoxia inducible factor-1αaccumulation in steatotic liver preservation:Role of nitric oxide

    Institute of Scientific and Technical Information of China (English)

    Mohamed; Amine; Zaouali; Ismail; Ben; Mosbah; Eleonora; Boncompagni; Hassen; Ben; Abdennebi; Maria; Teresa; Mitjavila; Ramon; Bartrons; Isabel; Freitas; Antoni; Rimola; Joan; Roselló-Catafau

    2010-01-01

    AIM:To examine the relevance of hypoxia inducible factor(HIF-1)and nitric oxide(NO)on the preservation of fatty liver against cold ischemia-reperfusion injury(IRI). METHODS:We used an isolated perfused rat liver model and we evaluated HIF-1αin steatotic and non-steatotic livers preserved for 24 h at 4℃in University of Wisconsin and IGL-1 solutions,and then subjected to 2 h of normothermic reperfusion.After normoxic reperfusion,liver enzymes,bile production,bromosulfophthalein clearance,as well as HIF-1αand ...

  4. Temporal expression of hepatic inducible nitric oxide synthase in liver cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Chang-Li Wei; Wei-Min Hon; Kang-Hoe Lee; Hoon-Eng Khoo

    2005-01-01

    AIM: Nitric oxide (NO) has been implicated in the pathogenesis of liver cirrhosis. We have found inducible nitric oxide synthase (iNOS) can be induced in hepatocytes of cirrhotic liver. This study further investigated the temporal expression and activity of hepatic iNOS in cirrhosis development.METHODS: Cirrhosis was induced in rats by chronic bile duct ligation (BDL). At different time points after the operation,samples were collected to examine NO concentration, liver function, and morphological changes. Hepatocytes were isolated for determination of iNOS mRNA, protein and enzymatic activity.RESULTS: Histological examination showed early cirrhosis 1-2 wk after BDL, with advanced cirrhosis at 3-4 wk.Bilirubin increased dramatically 3 d after BDL, but decreased by 47% on d 14. Three weeks after BDL, it elevated again. Systemic NO concentration did not increase significantly until 4 wk after BDL, when ascites developed.Hepatocyte iNOS mRNA expression was identified 3 d after BDL, and enhanced with time to 3 wk, but reduced thereafter. iNOS protein showed a similar pattern to mRNA expression. iNOS activity decreased from d 3 to d 7, but increased again thereafter till d 21.CONCLUSION: Hepatic iNOS can be induced in the early stage, which increases with time as cirrhosis develops. Its enzymatic activity is significantly correlated with protein expression and histological alterations of the liver, but not with systemic NO levels, nor with absolute values of liver function markers.

  5. Protective effect of nitric oxide induced by ischemic preconditioning on reperfusion injury of rat liver graft

    Institute of Scientific and Technical Information of China (English)

    Jian-Ping Gong; Bing Tu; Wei Wang; Yong Peng; Shou-Bai Li; Lu-Nan Yan

    2004-01-01

    AIM: Ischemic preconditioning (IP) is a brief ischemic episode,which confers a state of protection against the subsequent long-term ischemia-reperfusion injuries. However, little is known regarding the use of IP before the sustained cold storage and liver transplantation. The present study was designed to evaluate the protective effect of IP on the long-term preservation of liver graft and the prolonged anhepatic-phase injury.METHODS: Male Sprague-Dawley rats were used as donors and recipients of orthotopic liver transplantation. All livers underwent 10 min of ischemia followed by 10 min of reperfusion before harvest. Rat liver transplantation was performed with the portal vein clamped for 25 min. Tolerance of transplanted liver to the reperfusion injury and liverdamage were investigated. The changes in adenosineconcentration in hepatic tissue and those of nitric oxide (NO)and tumor necrosis factor (TNF) in serum were also assessed.RESULTS: Recipients with IP significantly improved theirone-week survival rate and liver function, they had increasedlevels of circulating NO and hepatic adenosine, and a reducedlevel of serum TNF, as compared to controls. Histologicalchanges indicating hepatic injuries appeared improved in theIP group compared with those in control group. The protectiveeffect of IP was also obtained by administration of adenosine,while blockage of the NO pathway using Nω-nitro-L-argininemethyl ester abolished the protective effect of IRCONCLUSION: IP appears to have a protective effect onthe long-term preservation of liver graft and the prolongedanhepatic-phase injuries. NO may be involved in this process.

  6. Type I Interferon Supports Inducible Nitric Oxide Synthase in Murine Hepatoma Cells and Hepatocytes and during Experimental Acetaminophen-Induced Liver Damage.

    Science.gov (United States)

    Bachmann, Malte; Waibler, Zoe; Pleli, Thomas; Pfeilschifter, Josef; Mühl, Heiko

    2017-01-01

    Cytokine regulation of high-output nitric oxide (NO) derived from inducible NO synthase (iNOS) is critically involved in inflammation biology and host defense. Herein, we set out to characterize the role of type I interferon (IFN) as potential regulator of hepatic iNOS in vitro and in vivo. In this regard, we identified in murine Hepa1-6 hepatoma cells a potent synergism between pro-inflammatory interleukin-β/tumor necrosis factor-α and immunoregulatory IFNβ as detected by analysis of iNOS expression and nitrite release. Upregulation of iNOS by IFNβ coincided with enhanced binding of signal transducer and activator of transcription-1 to a regulatory region at the murine iNOS promoter known to support target gene expression in response to this signaling pathway. Synergistic iNOS induction under the influence of IFNβ was confirmed in alternate murine Hepa56.1D hepatoma cells and primary hepatocytes. To assess iNOS regulation by type I IFN in vivo, murine acetaminophen (APAP)-induced sterile liver inflammation was investigated. In this model of acute liver injury, excessive necroinflammation drives iNOS expression in diverse liver cell types, among others hepatocytes. Herein, we demonstrate impaired iNOS expression in type I IFN receptor-deficient mice which associated with diminished APAP-induced liver damage. Data presented indicate a vital role of type I IFN within the inflamed liver for fine-tuning pathological processes such as overt iNOS expression.

  7. Type I Interferon Supports Inducible Nitric Oxide Synthase in Murine Hepatoma Cells and Hepatocytes and during Experimental Acetaminophen-Induced Liver Damage

    Science.gov (United States)

    Bachmann, Malte; Waibler, Zoe; Pleli, Thomas; Pfeilschifter, Josef; Mühl, Heiko

    2017-01-01

    Cytokine regulation of high-output nitric oxide (NO) derived from inducible NO synthase (iNOS) is critically involved in inflammation biology and host defense. Herein, we set out to characterize the role of type I interferon (IFN) as potential regulator of hepatic iNOS in vitro and in vivo. In this regard, we identified in murine Hepa1-6 hepatoma cells a potent synergism between pro-inflammatory interleukin-β/tumor necrosis factor-α and immunoregulatory IFNβ as detected by analysis of iNOS expression and nitrite release. Upregulation of iNOS by IFNβ coincided with enhanced binding of signal transducer and activator of transcription-1 to a regulatory region at the murine iNOS promoter known to support target gene expression in response to this signaling pathway. Synergistic iNOS induction under the influence of IFNβ was confirmed in alternate murine Hepa56.1D hepatoma cells and primary hepatocytes. To assess iNOS regulation by type I IFN in vivo, murine acetaminophen (APAP)-induced sterile liver inflammation was investigated. In this model of acute liver injury, excessive necroinflammation drives iNOS expression in diverse liver cell types, among others hepatocytes. Herein, we demonstrate impaired iNOS expression in type I IFN receptor-deficient mice which associated with diminished APAP-induced liver damage. Data presented indicate a vital role of type I IFN within the inflamed liver for fine-tuning pathological processes such as overt iNOS expression. PMID:28824623

  8. Effects of endogenous nitric oxide induced by 5-fluorouracil and L-Arg on liver carcinoma in nude mice

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To study the effects of endogeous nitric oxide induced by 5-fluorouracil (5-FU) and L-arginine (L-Arg)on the human liver carcinoma model in nude mice.METHODS: The human liver carcinoma model in nude mice was established with BEL-7402 cells and normal saline (NS), 5-FU and 5-FU + L-Arg injected intraperitoneally. The tumor size was measured. The necrotic degree and range were observed under microscope. The apoptosis of cancer cell was detected by turmina deoxynucleotidyl transferanse mediated dUTP nick end labeling (TUNEL) method. Immunohistochemical method was performed to determine the expression of iNOS, P16, BAX. The chemical colorimetry was used to test the activity and nitrate reductase method was adopted to test the concentration of nitric oxide (NO) in the tumor tissue. The BI2000 pathological image analyzer was used to analyze the result of immunohistochemistry.RESULTS: 5-FU combined with L-Arg could inhibit the tumor growth apparently. In NS, 5-FU and 5-FU+L-Arg groups, the changes of tumor volumes were 257.978 ± 59.0, 172.232 ± 66.0 and 91.523 ± 26.7 mm3,respectively (P < 0.05 5-FU vs 5-FU + L-Arg group;P < 0.05 NS vs 5-FU + L-Arg group; P < 0.05, NS vs 5-FU group).The necrotic range and apoptosis index were significantly increased after the drug injection. The necrotic range was biggest in 5-FU + L-Arg group (x2 = 15.963, P < 0.05).The apoptosis indexes were as follows: NS, 17.4% ± 6.19%; 5-FU, 31.3% ± 12.3%; and 5-FU + L-Arg, 46% ± 15.24% (P < 0.05, 5-FU vs 5-FU + L-Arg; P < 0.05, NS vs 5-FU + L-Arg; P < 0.05, NS vs 5-FU). The expression and activity of iNOS were increased in the tumor tissue.The concentration of NO was also increased. F of optical density of iNOS, iNOS activity and NO concentration are 31.693, 21.949, and 33.909, respectively, P < 0.05. The concentration of NO was related to the expression of P16 and BAX. The correlation coefficient was 0.764 and 0.554.CONCLUSION: 5-FU combined with L-Arg can inhibit the

  9. Induction of Inducible Nitric Oxide Synthase by Lipopolysaccharide and the Influences of Cell Volume Changes, Stress Hormones and Oxidative Stress on Nitric Oxide Efflux from the Perfused Liver of Air-Breathing Catfish, Heteropneustes fossilis.

    Science.gov (United States)

    Choudhury, Mahua G; Saha, Nirmalendu

    2016-01-01

    The air-breathing singhi catfish (Heteropneustes fossilis) is frequently being challenged by bacterial contaminants, and different environmental insults like osmotic, hyper-ammonia, dehydration and oxidative stresses in its natural habitats throughout the year. The main objectives of the present investigation were to determine (a) the possible induction of inducible nitric oxide synthase (iNOS) gene with enhanced production of nitric oxide (NO) by intra-peritoneal injection of lipopolysaccharide (LPS) (a bacterial endotoxin), and (b) to determine the effects of hepatic cell volume changes due to anisotonicity or by infusion of certain metabolites, stress hormones and by induction of oxidative stress on production of NO from the iNOS-induced perfused liver of singhi catfish. Intra-peritoneal injection of LPS led to induction of iNOS gene and localized tissue specific expression of iNOS enzyme with more production and accumulation of NO in different tissues of singhi catfish. Further, changes of hydration status/cell volume, caused either by anisotonicity or by infusion of certain metabolites such as glutamine plus glycine and adenosine, affected the NO production from the perfused liver of iNOS-induced singhi catfish. In general, increase of hydration status/cell swelling due to hypotonicity caused decrease, and decrease of hydration status/cell shrinkage due to hypertonicity caused increase of NO efflux from the perfused liver, thus suggesting that changes in hydration status/cell volume of hepatic cells serve as a potent modulator for regulating the NO production. Significant increase of NO efflux from the perfused liver was also observed while infusing the liver with stress hormones like epinephrine and norepinephrine, accompanied with decrease of hydration status/cell volume of hepatic cells. Further, oxidative stress, caused due to infusion of t-butyl hydroperoxide and hydrogen peroxide separately, in the perfused liver of singhi catfish, resulted in

  10. How to protect liver graft with nitric oxide

    Institute of Scientific and Technical Information of China (English)

    Hassen Ben Abdennebi; Mohamed Amine Zaoualí; Izabel Alfany-Fernandez; Donia Tabka; Joan Roselló-Catafau

    2011-01-01

    Organ preservation and ischemia reperfusion injury associated with liver transplantation play an important role in the induction of graft injury. One of the earliest events associated with the reperfusion injury is endothelial cell dysfunction. It is generally accepted that endothelial nitric oxide synthase (e-NOS) is cell-protective by mediating vasodilatation, whereas inducible nitric oxide synthase mediates liver graft injury after transplantation. We conducted a critical review of the literature evaluating the potential applications of regulating and promoting e-NOS activity in liver preservation and transplantation, showing the most current evidence to support the concept that enhanced bioavailability of NO derived from e-NOS is detrimental to ameliorate graft liver preservation, as well as preventing subsequent graft reperfusion injury. This review deals mainly with the beneficial effects of promoting "endogenous" pathways for NO generation, via e-NOS inducer drugs in cold preservation solution, surgical strategies such as ischemic preconditioning, and alternative "exogenous" pathways that focus on the enrichment of cold storage liquid with NO donors. Finally, we also provide a basic bench-to-bed side summary of the liver physiology and cell signalling mechanisms that account for explaining the e-NOS protective effects in liver preservation and transplantation.

  11. Japanese herbal medicine, Saiko-keishi-to, prevents gut ischemia/reperfusion-induced liver injury in rats via nitric oxide

    Institute of Scientific and Technical Information of China (English)

    Yoshinori Horie; Mikio Kajihara; Shuka Mori; Yoshiyuki Yamagishi; Hiroyuki Kimura; Hironao Tamai; Shinzo Kato; Hiromasa Jshii

    2004-01-01

    AIM: To determine whether Saiko-keishi-to (TJ-10), a Japanese herbal medicine, could protect liver injury induced by gut ischemia/reperfusion (I/R), and to investigate the role of NO.METHODS: Male Wistar rats were exposed to 30-min gut ischemia followed by 60 min of reperfusion. Intravital microscopy was used to monitor leukocyte recruitment. Plasma tumor necrosis factor (TNF) levels and alanine aminotransferase intragastrically administered to rats for 7 d. A NO synthase inhibitor was administered.RESULTS: In control rats, gut I/R elicited increases in the number of stationary leukocytes, and plasma TNF levels and ALT activities were mitigated by pretreatment with TJ-10. Pretreatment with the NO synthase inhibitor diminished the protective effects of TJ-10 on leukostasis in the liver, and the increase of plasma TNF levels and ALT activities. Pretreatment with TJ-10 increased plasma nitrite/nitrate levels.CONCLUSION: TJ-10 attenuates the gut I/R-induced hepatic microvascular dysfunction and sequential hepatocellular injury via enhancement of NO production.

  12. Nitric oxide in liver inflammation and regeneration.

    Science.gov (United States)

    Martin-Sanz, Paloma; Hortelano, Sonsoles; Callejas, Nuria A; Goren, Nora; Casado, Marta; Zeini, Miriam; Boscá, Lisardo

    2002-12-01

    Hepatocytes express and release inflammatory mediators after challenge with bacterial cell wall molecules and proinflammatory cytokines. Nitric oxide synthase-2 (NOS-2) is expressed under these conditions and the high-output NO synthesis that follows contributes to the inflammatory response in this tissue and participates in the onset of several hepatopathies. However, in the course of liver regeneration, for example, after partial hepatectomy, NOS-2 is expressed at moderate levels and contributes to inhibit apoptosis and to favor progression in the cell cycle until the organ size and function are restored. The mechanisms involved in the regulation of NOS-2 expression under these conditions are revised.

  13. Cromoglycate, not ketotifen, ameliorated the injured effect of warm ischemia/reperfusion in rat liver: role of mast cell degranulation, oxidative stress, proinflammatory cytokine, and inducible nitric oxide synthase

    Directory of Open Access Journals (Sweden)

    El-Shitany NA

    2015-09-01

    Full Text Available Nagla A El-Shitany,1,2 Karema El-Desoky3 1Department of Pharmacology and Toxicology, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia; 2Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tanta University, Tanta, Egypt; 3Department of Pathology, Faculty of Medicine, Tanta University, Tanta, Egypt Abstract: Hepatic ischemia/reperfusion (ISCH/REP is a major clinical problem that is considered to be the most common cause of postoperative liver failure. Recently, mast cells have been proposed to play an important role in the pathophysiology of ISCH/REP in many organs. In contrast, the role played by mast cells during ISCH/REP-induced liver damage has remained an issue of debate. This study aimed to investigate the protective role of mast cells in order to search for an effective therapeutic agent that could protect against fatal ISCH/REP-induced liver damage. A model of warm ISCH/REP was induced in the liver of rats. Four groups of rats were used in this study: Group I: SHAM (normal saline, intravenously [iv]; Group II: ISCH/REP; Group III: sodium cromoglycate + ISCH/REP (CROM + ISCH/REP, and Group IV: ketotifen (KET + ISCH/REP (KET + ISCH/REP. Liver damage was assessed both histopathologically and biochemically. Mast cell degranulation was assessed histochemically. Lipid peroxidation (malondialdehyde [MDA] as well as the levels of glutathione (GSH, interleukin-6 (IL-6, and tumor necrosis factor alpha (TNF-α, the formation of nitric oxide (NO, and the expression of inducible NO synthase (iNOS were determined. The results of this study revealed increased mast cell degranulation in the liver during the acute phase of ISCH/REP. Moreover, CROM, but not KET, decreased the activity of alanine aminotransferase, aspartate aminotransferase, and lactic dehydrogenase and maintained normal liver tissue histology. Both CROM and KET protected against mast cell degranulation in the liver. In addition, both CROM and KET decreased IL

  14. Protection by nitric oxide against liver inflammatory injury in animals carrying a nitric oxide synthase-2 transgene.

    Science.gov (United States)

    Mojena, M; Hortelano, S; Castrillo, A; Diaz-Guerra, M J; Garcia-Barchino, M J; Saez, G T; Bosca, L

    2001-03-01

    The effect of pre-existent hepatic NO synthesis on liver injury induced by lipopolysaccharide was studied in animals carrying a nitric oxide synthase-2 (NOS-2) transgene under the control of the phosphoenolpyruvate carboxykinase (PEPCK) promoter. These animals expressed NOS-2 in liver cells under fasting conditions. Lipopolysaccharide-induced liver injury in D-galactosamine-conditioned mice, which enhanced notably the effect of the endotoxin on the liver, was impaired in animals expressing NOS-2. This protection against inflammatory liver damage was dependent on NO synthesis and was caused by an inhibition of nuclear factor kB (NF-kB) activity and an impairment of the synthesis of the proinflammatory cytokines tumor necrosis factor a and interleukin 1b. These data indicate that intrahepatic synthesis of NO protects liver by inhibiting the release of cascades of proinflammatory mediators and suggest a beneficial role for local delivery of NO in the control of liver injury.

  15. [The effect of N-stearoylethanolamine on the activity of antioxidant enzymes, content of lipid peroxidation products and nitric oxide in the blood plasma and liver of rats with induced insulin-resistance].

    Science.gov (United States)

    Onopchenko, O V; Kosiakova, H V; Horid'ko, T M; Berdyshev, A H; Mehed', O F; Hula, N M

    2013-01-01

    The influence of N-stearoylethanolamine (NSE) on the content of lipid peroxidation products, activity of antioxidant enzymes and the nitric oxide level in the liver and blood plasma of rats with insulin-resistance (IR) state was investigated. IR state was induced in rats by prolonged high-fat diet (58% of energy derived from fat) for 6 months combined with one injection of streptozotocin (15 mg/kg of body weight). The existence of IR state was estimated by results of glucoso-tolerance test and blood plasma insulin content. The level of lipid peroxides products was shown to be higher in the liver of insulin resistant animals as a result of reduced superoxide dismutase and catalase activity, however, glutathione peroxidase activity was increased. The increase of nitric-oxide content in the liver and blood plasma of high-fat diet rats compared with healthy control animals was also observed. The administration of the NSE suspension per os in a dose of 50 mg/kg during 2 weeks to the rats with induced insulin-resistance state contributed to the increase of superoxide dismutase, catalase and glutathione peroxidase activity. In consequence of antioxidant enzymes activation the intensity of POL process was decreased. The NSE administration caused normalization of nitric oxide level, restoring pro-/antioxidant balance in the liver and blood plasma of rats with IR state. In conclusion, the NSE administration to the rats with insulin-resistance state restored pro-/antioxidant balance and enhanced the content of nitric oxide, therefore, improving insulin sensitivity.

  16. The effect of N-acetylcysteine (NAC) on liver and renal tissue inducible nitric oxide synthase (iNOS) and tissue lipid peroxidation in obstructive jaundice stimulated by lipopolysaccharide (LPS).

    Science.gov (United States)

    Cağlikülekci, Mehmet; Pata, Cengiz; Apa, Duygu Dusmez; Dirlik, Musa; Tamer, Lulufer; Yaylak, Faik; Kanik, Arzu; Aydin, Suha

    2004-03-01

    Morbidity and mortality rates are very high in obstructive jaundice when it is associated with sepsis and multiple organ failure. Nitric oxide (NO) formation and increased expression of inducible nitric oxide synthase (iNOS) also take place in obstructive jaundice (OJ). N-Acetylcysteine (NAC) has a beneficial effect by demonstrating anti-inflammatory activity such as inhibits cytokine expression/release, inhibiting the adhesion molecule expression and inhibiting nuclear factor kappa B (NFkappaB). The aim of this study was to investigate the effects of NAC on liver and renal tissue iNOS, and liver tissue lipid peroxidation in lipopolysaccharide (LPS) induced obstructive jaundice. We randomized 48 rats into six groups. Group A: Sham group; group B: OJ group; group C: OJ+NAC; group D: OJ+LPS (Escherichia coli LPS serotype L-2630, 100mg, Sigma) group E: OJ+NAC+LPS; group F: OJ+LPS+NAC. NAC was started subcutaneously 100mg/kg. LPS was injected intraperitoneally and then at the tenth day we sacrificed the rats. Liver malondialdehyde (MDA) increased and liver ATPase decreased in groups B-D when compared to group A. After the administration of NAC (groups C-E), liver MDA levels decreased, tissue ATPase levels increased as compared to other groups. The liver and renal tissue iNOS expression was increased in groups B, D, and F. After the administration of NAC (groups C-E) the liver and renal tissue iNOS expression were decreased. Our results indicated that NAC prevented the deleterious effects of LPS in OJ by reducing iNOS expression via lipid peroxidation in liver and renal tissue; if it was administrated before LPS. But NAC failed to prevent the iNOS expression and lipid peroxidation if there was established endotoxemia in OJ.

  17. Cromoglycate, not ketotifen, ameliorated the injured effect of warm ischemia/reperfusion in rat liver: role of mast cell degranulation, oxidative stress, proinflammatory cytokine, and inducible nitric oxide synthase

    Science.gov (United States)

    El-Shitany, Nagla A; El-Desoky, Karema

    2015-01-01

    Hepatic ischemia/reperfusion (ISCH/REP) is a major clinical problem that is considered to be the most common cause of postoperative liver failure. Recently, mast cells have been proposed to play an important role in the pathophysiology of ISCH/REP in many organs. In contrast, the role played by mast cells during ISCH/REP-induced liver damage has remained an issue of debate. This study aimed to investigate the protective role of mast cells in order to search for an effective therapeutic agent that could protect against fatal ISCH/REP-induced liver damage. A model of warm ISCH/REP was induced in the liver of rats. Four groups of rats were used in this study: Group I: SHAM (normal saline, intravenously [iv]); Group II: ISCH/REP; Group III: sodium cromoglycate + ISCH/REP (CROM + ISCH/REP), and Group IV: ketotifen (KET) + ISCH/REP (KET + ISCH/REP). Liver damage was assessed both histopathologically and biochemically. Mast cell degranulation was assessed histochemically. Lipid peroxidation (malondialdehyde [MDA]) as well as the levels of glutathione (GSH), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α), the formation of nitric oxide (NO), and the expression of inducible NO synthase (iNOS) were determined. The results of this study revealed increased mast cell degranulation in the liver during the acute phase of ISCH/REP. Moreover, CROM, but not KET, decreased the activity of alanine aminotransferase, aspartate aminotransferase, and lactic dehydrogenase and maintained normal liver tissue histology. Both CROM and KET protected against mast cell degranulation in the liver. In addition, both CROM and KET decreased IL-6 and TNF-α. However, CROM, but not KET, decreased MDA formation and increased GSH. Furthermore, KET, but not CROM, increased both NO formation and iNOS expression. In conclusion, this study clearly demonstrated mast cell degranulation in warm ISCH/REP in the liver of rats. More importantly, CROM, but not KET, ameliorated the effect of ISCH/REP-induced

  18. Cromoglycate, not ketotifen, ameliorated the injured effect of warm ischemia/reperfusion in rat liver: role of mast cell degranulation, oxidative stress, proinflammatory cytokine, and inducible nitric oxide synthase.

    Science.gov (United States)

    El-Shitany, Nagla A; El-Desoky, Karema

    2015-01-01

    Hepatic ischemia/reperfusion (ISCH/REP) is a major clinical problem that is considered to be the most common cause of postoperative liver failure. Recently, mast cells have been proposed to play an important role in the pathophysiology of ISCH/REP in many organs. In contrast, the role played by mast cells during ISCH/REP-induced liver damage has remained an issue of debate. This study aimed to investigate the protective role of mast cells in order to search for an effective therapeutic agent that could protect against fatal ISCH/REP-induced liver damage. A model of warm ISCH/REP was induced in the liver of rats. Four groups of rats were used in this study: Group I: SHAM (normal saline, intravenously [iv]); Group II: ISCH/REP; Group III: sodium cromoglycate + ISCH/REP (CROM + ISCH/REP), and Group IV: ketotifen (KET) + ISCH/REP (KET + ISCH/REP). Liver damage was assessed both histopathologically and biochemically. Mast cell degranulation was assessed histochemically. Lipid peroxidation (malondialdehyde [MDA]) as well as the levels of glutathione (GSH), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α), the formation of nitric oxide (NO), and the expression of inducible NO synthase (iNOS) were determined. The results of this study revealed increased mast cell degranulation in the liver during the acute phase of ISCH/REP. Moreover, CROM, but not KET, decreased the activity of alanine aminotransferase, aspartate aminotransferase, and lactic dehydrogenase and maintained normal liver tissue histology. Both CROM and KET protected against mast cell degranulation in the liver. In addition, both CROM and KET decreased IL-6 and TNF-α. However, CROM, but not KET, decreased MDA formation and increased GSH. Furthermore, KET, but not CROM, increased both NO formation and iNOS expression. In conclusion, this study clearly demonstrated mast cell degranulation in warm ISCH/REP in the liver of rats. More importantly, CROM, but not KET, ameliorated the effect of ISCH/REP-induced

  19. Inducible nitric oxide synthase in renal transplantation

    NARCIS (Netherlands)

    Joles, JA; Vos, IH; Grone, HJ; Rabelink, TJ

    2002-01-01

    The importance of the endothelial isoform of nitric oxide synthase (eNOS) has been well established. Endothelium-derived nitric oxide has been shown to be essential for vascular homeostasis and modulation of eNOS has thus become a target in prevention of cardiovascular disease. The role of the induc

  20. Can Chronic Nitric Oxide Inhibition Improve Liver and Renal Dysfunction in Bile Duct Ligated Rats?

    Directory of Open Access Journals (Sweden)

    Mona Fouad Mahmoud

    2015-01-01

    Full Text Available The aims of the present work were to study the effects of chronic NO inhibition on liver cirrhosis and to analyze its relationship with liver and kidney damage markers. Two inhibitors of NO synthesis (inducible NO synthase (iNOS inhibitor, aminoguanidine (AG, and nonselective NOS inhibitor, L-nitroarginine methyl ester (L-NAME were administered for 6 weeks to bile duct ligated (BDL rats 3 days after surgery. The present study showed that BDL was associated with liver injury and renal impairment. BDL increased liver NO content and myeloperoxidase (MPO activity. This was corroborated by increased oxidative stress, TNF-α, TGF-1β, and MMP-13 genes overexpression. Although both drugs reduced NO synthesis and TNF-α gene overexpression, only AG improved renal dysfunction and liver damage and reduced liver oxidative stress. However, L-NAME exacerbated liver and renal dysfunction. Both drugs failed to modulate TGF-1β and MMP-13 genes overexpression. In conclusion, inhibition of NO production by constitutive nitric oxide synthase (cNOS plays a crucial role in liver injury and renal dysfunction while inhibition of iNOS by AG has beneficial effect. TNF-α is not the main cytokine responsible for liver injury in BDL model. Nitric oxide inhibition did not stop the progression of cholestatic liver damage.

  1. Expression of nitric oxide synthase in T-cell-dependent liver injury initiated by ConA in Kunming mice

    Institute of Scientific and Technical Information of China (English)

    张修礼; 曲建慧; 万谟彬; 权启镇; 孙自勤; 王要军; 江学良; 李文波

    2004-01-01

    Objective: To investigate whether nitric oxide synthase (NOS) is expressed in T-cell-dependent liver injury initiated by concanavalin A (ConA) in Kunming mice and study the possible effect of nitric oxide(NO) on liver injury models. Methods: Liver injury in Kunming mice was induced by administration of ConA through tail vein. Expression of NOS in the liver was detected by NADPH diaphorase staining method. The possible effect of NO on liver injury models was obtained by L-NAME injection to suppress synthesis of NO. Results: NOS has a strong expression in hepatocytes after ConA injection, especially in those close to the central vein, while only a weak expression was found in the epithelial cells in control group. Liver injury became more serious when NO synthesis was inhibited by L-NAME, accompanied by great malondialdehyde(MDA) increase in serum and severe intrahepatic vascular thrombosis. Conclusion: NOS markedly expressed in ConAinduced liver injury, which may subsequently promote nitric oxide synthesis. Increasement of nitric oxide has a protective effect on ConA-induced liver injury.

  2. Nitric Oxide and Prostaglandins Potentiate the Liver Regeneration Cascade

    Directory of Open Access Journals (Sweden)

    Jodi M Schoen Smith

    2006-01-01

    Full Text Available The liver has the remarkable ability to regenerate following damage or surgical resection. Although this feature of the liver has been studied for over 100 years, the trigger of the liver regeneration cascade remains controversial. Recent experimental evidence supports the hypothesis that nitric oxide (NO and prostaglandins (PGs, released secondary to an increase in the blood flow-to-liver mass ratio following two-thirds partial hepatectomy (PHx, work synergistically to trigger liver regeneration. To extend this research, the hypothesis that NO and PGs are potential therapeutic targets to potentiate the liver regeneration cascade is tested. The NO donor s-nitroso-n-acetylpenicillamine, the phosphodiesterase V antagonist zaprinast (ZAP and PGI2 each potentiated c-fos messenger RNA expression, an index of initiation of the liver regeneration cascade, following PHx. Also, the triple combination of s-nitroso-n-acetylpenicillamine, ZAP and PGI2 potentiated c-fos messenger RNA expression. These results support the hypothesis that NO and PGs can potentiate initiation of the regeneration cascade. An additional index of liver weight restoration 48 h after PHx was also used to test the hypothesis, because this index encompasses the entire liver regeneration cascade. ZAP and 6-keto-PGF1α, a stable metabolite of PGI2, and the combination of ZAP and 6-keto-PGF1α, each potentiated liver weight restoration 48 h after PHx. These results also provide support for the hypothesis that NO and PGs are possible therapeutic targets to potentiate liver regeneration following surgical resection.

  3. Immunologic role of nitric oxide in acute rejection of golden hamster to rat liver xenotransplantation

    Institute of Scientific and Technical Information of China (English)

    Tong-Jin Diao; Tong-Ye Yuan; You-Lin Li

    2002-01-01

    AIM: To evaluate the immunologic role and expressionsignificances of nitric oxide(NO), nitric oxide synthase(NOS),and its isoenzyme in acute rejection to liverxenografts from golden hamster in rat.METHODS: Liver transplantations were randomlydivided into five groups(n=6-9):isografts (group I );xenografts (groupⅡ); xenografts plus cyclosporinetreatment (group Ⅲ), xenografts pluscyclophosphamide treatment combined withsplenectomy (group Ⅳ), and xenografts usingcyclophosphamide in combination with splenectomy(group Ⅳ) and xenografts using splenectomy inaddition to cyclophosphamide and cyclosporinetreatments(group V) .The levels of ALT, TNF- α, andnitric oxide production(NOx) in serum of reciprentswere examined,and expressions of type Ⅱ (iNOS) andtypeⅢ (cNOS) nitric oxide synthase(NOS)-inducibleNOS(iNOS) and constitutive NOS(cNOS) wereobserved by NADPH diaphorase histochemical andimmunohistochemical staining.RESULTS: The level of serum ALT, activity of serumTNF-α and systemic levels of NO metabolite in groupsⅡand Ⅳ were higher than those of groups Ⅰ andy(serum ALT, 2416±475, 2540±82.5) nkat. L-1 vs(556.8±43.5, 677.30±38.2 ) nkat. L-1, P<0.01;(serum TNF-α, 353.5±16.1,444.6±28.1) ng.L-1 vs38.5±5.2, 52.0±5.7) ng.L-1, P<0.01; (serum NOx514.6 ± 18.1, 336.0 ± 43.0 )nmol.g-1, vs 26.1 ± 5.7, 27.7±6.0) nmol.g-1, P<0.01.Cyclosporine in group Ⅲcan repress the cellular immune response and thesynthesis of nitric oxide and the expression of NOsynthase,but not prolong the liver xenograftsurvival.The over-expression of NOS, iNOS and cNOSin liver xenograft rejection in groups Ⅱand Ⅳ weredetected by NADPH diaphorase histochemical andimmunohistochemical staining.CONCLUSION: The degrees of acute rejection can beeffectively repressed in golden hamster to rat liverxenografts with splenectomy and cyclosporine. Nitricoxide metabolites, and nitric oxide synthase and itsisoenzymes,above all inducible NOS (iNOS) can beused as potential diagnostic

  4. Nitric oxide synthase and heme oxygenase expressions in human liver cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Beatrice J Goh; Bee Tee Tan; Wei Min Hon; Kang Hoe Lee; Hoon Eng Khoo

    2006-01-01

    AIM: Portal hypertension is a common complication of liver cirrhosis. Intrahepatic pressure can be elevated in several ways. Abnormal architecture affecting the vasculature, an increase in vasoconstrictors and increased circulation from the splanchnic viscera into the portal system may all contribute. It follows that endogenous vasodilators may be able to alleviate the hypertension. We therefore aimed to investigate the levels of endogenous vasodilators, nitric oxide (NO) and carbon monoxide (CO) through the expression of nitric oxide synthase (NOS) and heme oxygenase (HO).METHOD: Cirrhotic (n= 20) and non-cirrhotic (n = 20) livers were obtained from patients who had undergone surgery. The mRNA and protein expressions of the various isoforms of NOS and HO were examined using competitive PCR, Western Blot and immunohistochemistry.RESULTS: There was no significant change in either inducible NOS (iNOS) or neuronal NOS (nNOS) expressions while endothelial NOS (eNOS) was upregulated in cirrhotic livers. Concomitantly, caveolin-1, an established down-regulator of eNOS, was up-regulated.Inducible HO-1 and constitutive HO-2 were found to show increased expression in cirrhotic livers albeit in different localizations.CONCLUSION: The differences of NOS expression might be due to their differing roles in maintaining liver homeostasis and/or involvement in the pathology of cirrhosis. Sheer stress within the hypertensive liver may induce increased expression of eNOS. In turn, caveolin-1 is also increased. Whether this serves as a defense mechanism against further cirrhosis or is a consequence of cirrhosis, is yet unknown. The elevated expression of HO-1 and HO-2 suggest that CO may compensate in its role as a vasodilator albeit weakly. It is possible that CO and NO have parallel or coordinated functions within the liver and may work antagonistically in the pathophysiology of portal hypertension.

  5. Graft reconditioning with nitric oxide gas in rat liver transplantation from cardiac death donors.

    Science.gov (United States)

    Kageyama, Shoichi; Yagi, Shintaro; Tanaka, Hirokazu; Saito, Shunichi; Nagai, Kazuyuki; Hata, Koichiro; Fujimoto, Yasuhiro; Ogura, Yasuhiro; Tolba, Rene; Shinji, Uemoto

    2014-03-27

    Liver transplant outcomes using grafts donated after cardiac death (DCD) remain poor. We investigated the effects of ex vivo reconditioning of DCD grafts with venous systemic oxygen persufflation using nitric oxide gas (VSOP-NO) in rat liver transplants. Orthotopic liver transplants were performed in Lewis rats, using DCD grafts prepared using static cold storage alone (group-control) or reconditioning using VSOP-NO during cold storage (group-VSOP-NO). Experiment I: In a 30-min warm ischemia model, graft damage and hepatic expression of inflammatory cytokines, endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and endothelin-1 (ET-1) were examined, and histologic analysis was performed 2, 6, 24, and 72 hr after transplantation. Experiment II: In a 60-min warm ischemia model, grafts were evaluated 2 hr after transplantation (6 rats/group), and survival was assessed (7 rats/group). Experiment I: Group-VSOP-NO had lower alanine aminotransferase (ALT) (PVSOP-NO.Experiment II: VSOP-NO decreased ET-1 and 8-hydroxy-2'deoxyguanosine (8-OHdG) expression and improved survival after transplantation by 71.4% (PVSOP-NO effectively reconditions warm ischemia-damaged grafts, presumably by decreasing ET-1 upregulation and oxidative damage.

  6. Biliverdin Reductase-A correlates with inducible nitric oxide synthasein in atorvastatin treated aged canine brain

    Institute of Scientific and Technical Information of China (English)

    Fabio Di Domenico; Marzia Perluigi; Eugenio Barone

    2013-01-01

    Alzheimer’s disease is a neurodegenerative disorder characterized by progressive cognitive impairment and neuropathology. Recent preclinical and epidemiological studies proposed statins as a possible therapeutic drug for Alzheimer’s disease, but the exact mechanisms of action are stil unknown. Biliverdin reductase-A is a pleiotropic enzyme involved in cel ular stress responses. It not only transforms biliverdin-IX alpha into the antioxidant bilirubin-IX alpha but its serine/threonine/tyrosine kinase activity is able to modulate cel signaling networks. We previously reported the beneficial effects of atorvastatin treatment on biliverdin reductase-A and heme oxygenase-1 in the brains of a well characterized pre-clinical model of Alzheimer’s disease, aged beagles, together with observed improvement in cognition. Here we extend our knowledge of the effects of atorvastatin on inducible nitric oxide synthase in parietal cortex, cerebel um and liver of the same animals. We demonstrated that atorvastatin treatment (80 mg/day for 14.5 months) to aged beagles selectively increased inducible nitric oxide synthase in the parietal cortex but not in the cerebel um. In contrast, inducible nitric oxide synthase protein levels were significantly decreased in the liver. Significant positive correlations were found between biliverdin reductase-A and inducible nitric oxide synthase as wel as heme oxygenase-1 protein levels in the parietal cortex. The opposite was observed in the liver. Inducible nitric oxide synthase up-regulation in the parietal cortex was positively associated with improved biliverdin reductase-A functions, whereas the oxidative-induced impairment of biliverdin reductase-A in the liver negatively affected inducible nitric oxide synthase expression, thus suggesting a role for biliverdin reductase-A in atorvastatin-dependent inducible nitric oxide synthase changes. Interestingly, increased inducible nitric oxide synthase levels in the parietal cortex were not

  7. Nitric oxide, inducible nitric oxide synthase and inflammation in veterinary medicine.

    Science.gov (United States)

    Hunter, Robert P

    2002-12-01

    Inflammation is a process consisting of a complex of cytological and chemical reactions which occur in and around affected blood vessels and adjacent tissues in response to an injury caused by a physical, chemical or biological insult. Much work has been performed in the past several years investigating inducible nitric oxide synthase (NOS, EC 1.14.13.39) and nitric oxide in inflammation. This has resulted in a rapid increase in knowledge about iNOS and nitric oxide. Nitric oxide formation from inducible NOS is regulated by numerous inflammatory mediators, often with contradictory effects, depending upon the type and duration of the inflammatory insult. Equine medicine appears to have benefited the most from the increased interest in this small, inflammatory mediator. Most of the information on nitric oxide in traditional veterinary species has been produced using models or naturally occurring inflammatory diseases of this species.

  8. Inducible nitric oxide synthase mediates bone loss in ovariectomized mice.

    NARCIS (Netherlands)

    Cuzzocrea, S.; Mazzon, E.; Dugo, L.; Genovese, T.; Paola, R. Di; Ruggeri, Z.; Vegeto, E.; Caputi, A.P.; Loo, F.A.J. van de; Puzzolo, D.; Maggi, A.

    2003-01-01

    Several clinical studies have shown that bone loss may be attributed to osteoclast recruitment induced by mediators of inflammation. In different experimental paradigms we have recently demonstrated that estrogen exhibits antiinflammatory activity by preventing the induction of inducible nitric

  9. Inducible nitric oxide synthase mediates bone loss in ovariectomized mice.

    NARCIS (Netherlands)

    Cuzzocrea, S.; Mazzon, E.; Dugo, L.; Genovese, T.; Paola, R. Di; Ruggeri, Z.; Vegeto, E.; Caputi, A.P.; Loo, F.A.J. van de; Puzzolo, D.; Maggi, A.

    2003-01-01

    Several clinical studies have shown that bone loss may be attributed to osteoclast recruitment induced by mediators of inflammation. In different experimental paradigms we have recently demonstrated that estrogen exhibits antiinflammatory activity by preventing the induction of inducible nitric oxid

  10. Drug-induced liver injury

    DEFF Research Database (Denmark)

    Nielsen, Mille Bækdal; Ytting, Henriette; Skalshøi Kjær, Mette

    2017-01-01

    OBJECTIVE: The idiosyncratic subtype of drug-induced liver injury (DILI) is a rare reaction to medical treatment that in severe cases can lead to acute liver failure and death. The aim of this study was to describe the presentation and outcome of DILI and to identify potential predictive factors...... biochemical findings included bilirubin elevated to above 3.2 × ULN, ALT elevated to above 9 × ULN in 86%, INR above 1.4 in 70%. Twenty two patients needed treatment in the liver intensive care unit. Fifteen patients developed acute liver failure with a severe outcome. Six patients were liver transplanted...... and nine patients died. Jaundice, a moderately elevated bilirubin level or INR at presentation was predictive of severe outcome. CONCLUSION: In this retrospective study, 35% of patients with DILI developed severe acute liver failure and were either liver transplanted or died. Our results underline...

  11. Abacavir-induced liver toxicity

    Directory of Open Access Journals (Sweden)

    Maria Diletta Pezzani

    Full Text Available Abstract Abacavir-induced liver toxicity is a rare event almost exclusively occurring in HLA B*5701-positive patients. Herein, we report one case of abnormal liver function tests occurring in a young HLA B*5701-negative woman on a stable nevirapine-based regimen with no history of liver problems or alcohol abuse after switching to abacavir from tenofovir. We also investigated the reasons for abacavir discontinuation in a cohort of patients treated with abacavir-lamivudine-nevirapine.

  12. Abacavir-induced liver toxicity.

    Science.gov (United States)

    Pezzani, Maria Diletta; Resnati, Chiara; Di Cristo, Valentina; Riva, Agostino; Gervasoni, Cristina

    2016-01-01

    Abacavir-induced liver toxicity is a rare event almost exclusively occurring in HLA B*5701-positive patients. Herein, we report one case of abnormal liver function tests occurring in a young HLA B*5701-negative woman on a stable nevirapine-based regimen with no history of liver problems or alcohol abuse after switching to abacavir from tenofovir. We also investigated the reasons for abacavir discontinuation in a cohort of patients treated with abacavir-lamivudine-nevirapine.

  13. Drug-induced liver injuries

    African Journals Online (AJOL)

    most clinicians and is synonymous with drug-induced hepatotoxicity. A succinct ... or herbal medicine resulting in liver test abnormalities or liver dysfunction with a ... and exclusion of other common aetiological factors, e.g. viral hepatitis. .... chronic alcohol use and hepatitis B or C infection. As a combination of drugs is used.

  14. The plasma level of nitric oxide and the expression of inducible nitric oxidesynthase in human hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Run Xuan Shao; Jiang Bin Wang; Jia He Guo

    2000-01-01

    AIM To study the relationship between nitric oxide (NO), nitric oxide synthase (NOS) and humanhepatocellular carcinoma (HCC).METHODS Plsama NO2-/NO3- was measured by Griess reaction in 122 patients with chronic hepatitis(CH) and compensated liver cirrhosis (LC), among which 62 patients were complicated with HCC(CH = 28, LC = 34), and the rest 60 patients were not (CH = 29, LC = 31). Thirty healthy persons served asnormal controls (NC). There were no prominent differences among the groups in sex, age and the ratio ofCH to LC. The expression of inducible nitric oxide synthase (iNOS) in HCC (n = 40), CH (n = 30) and LC(n = 30) samples obtained from liver biopsy or operation was compared with that in normal liver tissues byusing immunohistochemistry. Ten normal liver tissue samples obtained from liver operation served as normalcontrols. The samples were fixed in formalin and embeded in paraffin. Anti-iNOS antibody (Santacruzcompany) was served as antibody-Ⅰ in immunohistochemical assay of iNOS in tissue.RESULTS Plasma NO2-/NO3- level in normal was 11.5 μmol/L±4.2μmol/L. The plasma level ofNO2 /NO3- in CH (58.6±17.4 μmol/L) and LC (38.7±10.6μmol/L) accompanied with HCC wasnotably higher than in those patients without HCC (CH: 24.8±9.4 μmol/L; LC: 22.3±8.7μmol/L,t=2.901, 2.756, P<0.01). Plasma NO2-/NO3- level in HCC accompanied with CH was significantlyhigher than in those accompanied with LC ( t = 2.216, P<0.05). Positive rate of iNOS in HCC, CH and LCwas 95%, 93% and 57% respectively. iNOS was not expressed in normal liver tissues. The expression level ofiNOS in HCC (χ2=17.4, P<0.001) and CH (χ2=11.64, P<0.025) was much higher than in LC.CONCLUSION Plasma NO2 / NO3- level significantly increased in patients with HCC and theimmunohistochemical staining of iNOS was positive. This suggests that the liver secrets NO in the higherlevel may participate in the carcinogenesis and progression of HCC.

  15. Naproxen-induced liver injury

    Institute of Scientific and Technical Information of China (English)

    Sharif Ali; Jason D Pimentel; Chan Ma

    2011-01-01

    BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) have been reported to induce liver injury. Patterns of the injury usually range from mild elevations of liver enzymes to sometimes severe fulminant hepatic failure. Likewise, naproxen is a propionic acid derivative NSAID that was introduced in 1980 and has been available as an over-the-counter medication since 1994, but has rarely been reported to cause liver injury. METHODS: We treated a 30-year-old woman with jaundice and intractablepruritusthatdevelopedshortlyaftertakingnaproxen. We reviewed the medical history and liver histopathology of the patient as well as all previously published case reports of naproxen-associated liver toxicity in the English language literature. RESULTS: The liver biochemical profile of the patient revealed a mixed cholestasis and hepatitis pattern. Consecutive liver biopsies demonstrated focal lobular inflammation, hepatocyte drop-out, and a progressive loss of the small interlobular bile ducts (ductopenia). The biopsy performed two years after onset of the disease showed partial recovery of a small number of bile ducts; however, 10 years passed before the biochemical profile returned to near normal. CONCLUSIONS:  Naproxen-associated liver toxicity remains a rare entity, but should be considered in any patient presenting with cholestasis shortly after its use. Liver injury is most commonly seen in a mixed pattern characterized by cholestasis and hepatitis. The resulting liver damage may take years to resolve.

  16. Increased nitric oxide release and expression of endothelial and inducible nitric oxide synthases in mildly changed porcine mitral valve leaflets

    DEFF Research Database (Denmark)

    Moesgaard, Sophia G; Olsen, Lisbeth H; Viuff, Birgitte M

    2007-01-01

    BACKGROUND AND AIM OF THE STUDY: Little is known of the local role of nitric oxide (NO) in heart valves in relation to heart valve diseases. The study aim was to examine NO release and the expression of both endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in re...

  17. Increased nitric oxide release and expression of endothelial and inducible nitric oxide synthases in mildly changed porcine mitral valve leaflets

    DEFF Research Database (Denmark)

    Moesgaard, Sophia Gry; Olsen, Lisbeth Høier; Viuff, Birgitte;

    2007-01-01

    Background and aim of the study: Little is known of the local role of nitric oxide (NO) in heart valves in relation to heart valve diseases. The study aim was to examine NO release and the expression of both endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (i...

  18. Distribution of nitric oxide synthase positive neurons in the substantia nigra of rats with liver cirrhosis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND:Nitrogen monoxide plays an important role in the physiological activity and pathological process of striatum in substantia nigra, and the nitric oxide synthase in substantia nigra may have characteristic changes after liver cirrhosis.OBJECTIYE: To observe the distribution and forms of nitric oxide synthase (NOS) positive neurons and fibers in substantia nigra of rats with liver cirrhosis.DESIGN: A comparative observational experiment.SETTINGS: Beijing Friendship Hospital; Capital Medical University.MATERIALS: Twenty 4-month-old male Wistar rats (120 - 150 g) of clean grade, were maintained in a 12-hour light/dark cycle at a constant temperature with free access to standard diet and water. Cryostat microtome (LEICA, Germany); All the reagents were purchased from Sigma Company.METHODS: The experiment was carried out in the Department of Anatomy (key laboratory of Beijing city),Capital Medical University from July 2000 to March 2002. The rats were randomly divided into normal group (n=10) and liver fibrosis group (n=10). Rats in the liver fibrosis group were subcutaneously injected with 60% CCl4 oil at a dose of 5 mL/kg for the first time, and 3 mL/kg for the next 14 times, twice a week,totally 15 times. Liver fibrosis of grades 5 - 6 was taken as successful models. Whereas rats in the normal group were not given any treatment. Four months after CCl4 treatment, all the rats were anesthetized to remove brain, and frontal frozen serial sections were prepared. The expressions of nitric oxide synthase positive neurons in substantia nigra of rats were observed under inverted microscope. The number and gray scale of cell body of nitric oxide synthase positive neurons in substantia nigra were detected with NADPH-diaphorase staining.MAIN OUTCOME MEASURES: ①Number and gray scale of cell body of nitric oxide synthase positive neurons in substantia nigra; ②Expressions of nitric oxide synthase positive neurons in substantia nigra.RESULTS: All the 20 rats were

  19. Nitric oxide damages neuronal mitochondria and induces apoptosis in neurons

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The cytotoxic effect of nitric oxide on primarily cultured rat cerebellar granule cells was studied,and the mechanisms were discussed.The results showed that nitric oxide donor S-nitroso-N-acetyl-penicillamine (SNAP; 500 μmol/L) could induce apoptosis in immature cultures of cerebellar granule cells.Flow cytometry and HPLC analyses revealed that after treatment with SNAP,the mitochondrial transmembrane potential and the cellular ATP content decreased significantly.Nitric oxide scavenger hemoglobin could effectively prevent the neuronal mitochondria from dysfunction and attenuate apoptosis.The results suggested that nitric oxide activated the apoptotic program by inhibiting the activity of mitochondrial respiratory chain and thus decreasing the cellular ATP content.

  20. Inhibitory effects of coumarin and acetylene constituents from the roots of Angelica furcijuga on D-galactosamine/lipopolysaccharide-induced liver injury in mice and on nitric oxide production in lipopolysaccharide-activated mouse peritoneal macrophages.

    Science.gov (United States)

    Yoshikawa, Masayuki; Nishida, Norihisa; Ninomiya, Kiyofumi; Ohgushi, Teruki; Kubo, Mizuho; Morikawa, Toshio; Matsuda, Hisashi

    2006-01-15

    The methanolic extract (200 mg/kg, p.o. and i.p.), principal coumarin constituents (isoepoxypteryxin, anomalin, and praeroside IV), and a polyacetylene constituent (falcarindiol) (25 mg/kg, i.p.) from the roots of Angelica furcijuga protected the liver injury induced by D-galactosamine (D-GalN)/lipopolysaccharide (LPS) in mice. In in vitro experiments, coumarin constituents (hyuganins A-D, anomalin, pteryxin, isopteryxin, and suksdorfin) and polyacetylene constituents [(-)-falcarinol and falcarindiol] substantially inhibited LPS-induced NO and/or TNF-alpha production in mouse peritoneal macrophages, and isoepoxypteryxin inhibited D-GalN-induced cytotoxicity in primary cultured rat hepatocytes. Furthermore, hyuganin A, anomalin, and isopteryxin inhibited the decrease in cell viability by TNF-alpha in L929 cells.

  1. A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage

    Directory of Open Access Journals (Sweden)

    Nevzat Selim Gokay

    2016-01-01

    Full Text Available The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg, inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg, or nitric oxide precursor L-arginine (200 mg/kg. After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P=0.044 positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders.

  2. Deficiency of nitric oxide in polycation-induced airway hyperreactivity

    NARCIS (Netherlands)

    Meurs, Herman; Schuurman, F.E; Duyvendak, M; Zaagsma, Hans

    1999-01-01

    Using a perfused guinea-pig tracheal tube preparation, we investigated the role of endogenous nitric oxide (NO) in polycation-induced airway hyperreactivity (AHR) to methacholine. Intraluminal (IL) administration of the NO synthase inhibitor N-omega-nitro-L-arginine methyl ester (L-NAME; 100 mu M) c

  3. [Nitric oxide].

    Science.gov (United States)

    Rovira, I

    1995-01-01

    Nitric oxide was identified as the relaxing factor derived from the endothelium in 1987. Nitric oxide synthesis allows the vascular system to maintain a state of vasodilation, thereby regulating arterial pressure. Nitric oxide is also found in platelets, where it inhibits adhesion and aggregation; in the immune system, where it is responsible for the cytotoxic action of macrophages; and in the nervous system, where it acts as neurotransmitter. A deficit in endogenous synthesis of nitric oxide contributes to such conditions as essential arterial hypertension, pulmonary hypertension and heart disease. An excess of nitrous oxide induced by endotoxins and cytokinins, meanwhile, is believed to be responsible for hypotension in septic shock and for hyperdynamic circulatory state in cirrhosis of the liver. Nitric oxide has also been implicated in the rejection of transplanted organs and in cell damage after reperfusion. Inhaled nitrous oxide gas reduces pulmonary hypertension without triggering systemic hypotension in both experimental and clinical conditions. It also produces selective vasodilation when used to ventilate specific pulmonary areas, thereby improving the ventilation/perfusion ratio and, hence, oxygenation. Nitric oxide inhalation is effective in pulmonary hypertension-coincident with chronic obstructive lung disease, in persistent neonatal pulmonary hypertension and in pulmonary hypertension with congenital or acquired heart disease. Likewise, it reduces intrapulmonary shunt in acute respiratory failure and improves gas exchange. Under experimental conditions nitric oxide acts as a bronchodilator, although it seems to be less effective for this purpose in clinical use.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Animal models for the study of liver regeneration: role of nitric oxide and prostaglandins.

    Science.gov (United States)

    Hortelano, Sonsoles; Zeini, Miriam; Casado, Marta; Martín-Sanz, Paloma; Boscá, Lisardo

    2007-01-01

    The mechanisms that permit adult tissues to regenerate are the object of intense study. Liver regeneration is a research area of considerable interest both from pathological and from physiological perspectives. One of the best models of the regenerative process is the two-thirds partial hepatectomy (PH). After PH, the remnant liver starts a series of timed responses that first favor cell growth and then halts hepatocyte proliferation once liver function is fully restored. The mechanisms regulating this process are complex and involve many cellular events. Initiation of liver regeneration requires the injury-related cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6), and involves the activation of cytokine-regulated transcription factors such as NF-kappaB and STAT3. An important event that takes place in the hours immediately after PH is the induction of nitric oxide synthase 2 (NOS-2) and cyclooxygenase 2 (COX-2), and the consequent release of nitric oxide (NO) and prostaglandins (PGs). NO is involved in the vascular readaptation after PH, favoring a general permeability to growth factors throughout the organ. This review examines the mechanisms that regulate NO release during liver regeneration and the animal models used to identify these pathways.

  5. Production of Nitric Oxide and Expression of Inducible Nitric Oxide Synthase in Ovarian Cystic Tumors

    Directory of Open Access Journals (Sweden)

    Rosekeila Simões Nomelini

    2008-01-01

    Full Text Available Tumor sections from nonneoplastic (n=15, benign (n=28, and malignant ovarian tumors (n=20 were obtained from 63 women. Immunohistochemistry of the tumor sections demonstrated that inducible nitric oxide synthase (iNOS expression was increased in ovarian cancer samples compared to nonneoplastic or benign tumor samples. Using the Griess method, nitric oxide (NO metabolite levels were also found to be elevated in malignant tumor samples compared to benign tumor samples (P80 μM were more frequent than NO levels <80 μM, and iNOS expression in well-differentiated carcinomas was greater than in moderately/poorly differentiated carcinomas (P<.05. These data suggest an important role for NO in ovarian carcinogenesis.

  6. Metal release in metallothioneins induced by nitric oxide: X-ray absorption spectroscopy study.

    Science.gov (United States)

    Casero, Elena; Martín-Gago, José A; Pariente, Félix; Lorenzo, Encarnación

    2004-12-01

    Metallothioneins (MTs) are low molecular weight proteins that include metal ions in thiolate clusters. The capability of metallothioneins to bind different metals has suggested their use as biosensors for different elements. We study here the interaction of nitric oxide with rat liver MTs by using in situ X-ray absorption spectroscopy techniques. We univocally show that the presence of NO induces the release of Zn atoms from the MT structure to the solution. Zn ions transform in the presence of NO from a tetrahedral four-fold coordinated environment in the MT into a regular octahedral six-fold coordinated state, with interatomic distances compatible with those of Zn solvated in water.

  7. Impact of venous-systemic oxygen persufflation with nitric oxide gas on steatotic grafts after partial orthotopic liver transplantation in rats.

    Science.gov (United States)

    Nagai, Kazuyuki; Yagi, Shintaro; Afify, Mamdouh; Bleilevens, Christian; Uemoto, Shinji; Tolba, Rene H

    2013-01-15

    Steatotic livers are associated with poor graft function after transplantation. We investigated the effects of venous-systemic oxygen persufflation with nitric oxide gas (VSOP-NO) on steatotic partial livers after transplantation. Steatotic livers induced by fasting for 2 days and subsequent refeeding for 3 days with a fat-free, carbohydrate-rich diet were reduced in size by 50% and transplanted into Lewis rats after 3 hr of cold storage in histidine-tryptophan-ketoglutarate solution. Gaseous oxygen with nitric oxide (40 ppm) was insufflated into the grafts through the suprahepatic vena cava during cold storage (VSOP-NO group; n=20). Transplantation of cold-static stored steatotic and normal grafts served as controls (Steatotic-Control and Normal-Control, respectively; n=20 for each group). The graft microcirculation and portal venous flow were increased by VSOP-NO compared with Steatotic-Control (PVSOP-NO versus Steatotic-Control group (P=0.03 for both). Messenger RNA expression for inducible nitric oxide synthase, which was increased in Steatotic-Control livers 3 hr after transplantation (P=0.02 vs. that at 1 hr), was suppressed by VSOP-NO. Although serum nitrite levels were decreased 1 hr after transplantation in Steatotic-Control (P=0.06 vs. Normal-Control), the VSOP-NO group showed increased levels comparable to Normal-Control. In livers 24 hr after transplantation, moderate vacuolization of hepatocytes by histology with the immunohistochemical expression of nitrotyrosine, indicative of nitrative stress, was found in Steatotic-Control, whereas these findings were less apparent in VSOP-NO-treated livers. Application of VSOP-NO for steatotic partial livers reduces hepatocellular damage and improves graft viability and microcirculation after transplantation.

  8. Nitric oxide-induced signalling in rat lacrimal acinar cells

    DEFF Research Database (Denmark)

    Looms, Dagnia Karen; Tritsaris, K.; Dissing, S.

    2002-01-01

    The aim of the present study was to investigate the physiological role of nitric oxide (NO) in mediating secretory processes in rat lacrimal acinar cells. In addition, we wanted to determine whether the acinar cells possess endogenous nitric oxide synthase (NOS) activity by measuring NO productio...... not by itself causing fast transient increases in [Ca2+]i. In addition, we suggest that endogenously produced NO activated by ß-adrenergic receptor stimulation, plays an important role in signalling to the surrounding tissue.......The aim of the present study was to investigate the physiological role of nitric oxide (NO) in mediating secretory processes in rat lacrimal acinar cells. In addition, we wanted to determine whether the acinar cells possess endogenous nitric oxide synthase (NOS) activity by measuring NO production......-adrenergic stimulation and not by a rise in [Ca2+]i alone.   We show that in rat lacrimal acinar cells, NO and cGMP induce Ca2+ release from intracellular stores via G kinase activation. However, the changes in [Ca2+]i are relatively small, suggesting that this pathway plays a modulatory role in Ca2+ signalling, thus...

  9. Celecoxib-induced cholestatic liver failure requiring orthotopic liver transplantation

    Institute of Scientific and Technical Information of China (English)

    Ihab I El Hajj; Shahid M Malik; Hany R Alwakeel; Obaid S Shaikh; Eizaburo Sasatomi; Hossam M Kandil

    2009-01-01

    Selective cyclooxygenase-2 (COX-2) inhibitors are widely used due to their efficacy and good safety profile.However, recent case reports have described varying degrees of liver injuries associated with the use of COX-2 inhibitors. We report the case of a patient who developed acute cholestatic hepatitis progressing to hepatic failure requiring liver transplantation, following a 3-d course of celecoxib for treatment of generalized muscle aches and pains. The clinical presentation, the laboratory data, as well as the liver histopathology were supportive of the putative diagnosis of drug induced liver injury.

  10. Clinical Significance of a Myeloperoxidase Gene Polymorphism and Inducible Nitric Oxide Synthase Expression in Cirrhotic Patients with Hepatopulmonary Syndrome

    Institute of Scientific and Technical Information of China (English)

    王燕颖; 王文多; 张艳霞; 赵欣; 杨东亮

    2010-01-01

    The clinical significance of a myeloperoxidase (MPO) gene polymorphism and inducible nitric oxide synthase (iNOS) expression in cirrhotic patients with hepatopulmonary syndrome (HPS) was explored. Enrolled subjects were divided into three groups according to their disease/health conditions: the HPS group (cirrhotic patients with HPS; n=63), the non-HPS group (cirrhotic patients without HPS; n=182), and the control group (healthy subjects without liver disease; n=35). The distribution of the MPO-463 G/A geno...

  11. Propylthiouracil-induced acute liver failure: role of liver transplantation.

    Science.gov (United States)

    Carrion, Andres F; Czul, Frank; Arosemena, Leopoldo R; Selvaggi, Gennaro; Garcia, Monica T; Tekin, Akin; Tzakis, Andreas G; Martin, Paul; Ghanta, Ravi K

    2010-01-01

    Propylthiouracil- (PTU-) induced hepatotoxicity is rare but potentially lethal with a spectrum of liver injury ranging from asymptomatic elevation of transaminases to fulminant hepatic failure and death. We describe two cases of acute hepatic failure due to PTU that required liver transplantation. Differences in the clinical presentation, histological characteristics, and posttransplant management are described as well as alternative therapeutic options. Frequent monitoring for PTU-induced hepatic dysfunction is strongly advised because timely discontinuation of this drug and implementation of noninvasive therapeutic interventions may prevent progression to liver failure or even death.

  12. Propylthiouracil-Induced Acute Liver Failure: Role of Liver Transplantation

    Directory of Open Access Journals (Sweden)

    Andres F. Carrion

    2010-01-01

    Full Text Available Propylthiouracil- (PTU- induced hepatotoxicity is rare but potentially lethal with a spectrum of liver injury ranging from asymptomatic elevation of transaminases to fulminant hepatic failure and death. We describe two cases of acute hepatic failure due to PTU that required liver transplantation. Differences in the clinical presentation, histological characteristics, and posttransplant management are described as well as alternative therapeutic options. Frequent monitoring for PTU-induced hepatic dysfunction is strongly advised because timely discontinuation of this drug and implementation of noninvasive therapeutic interventions may prevent progression to liver failure or even death.

  13. Prednisolone reduces nitric oxide-induced migraine

    DEFF Research Database (Denmark)

    Tfelt-Hansen, P; Daugaard, D; Lassen, L H

    2009-01-01

    BACKGROUND AND PURPOSE: Glyceryl trinitrate (GTN) induces delayed migraine attacks in migraine patients. The purpose of this study was to investigate whether pre-treatment with prednisolon could decrease this effect of GTN. METHODS: In this double-blind, randomized and placebo-controlled, crossover...... study 15 migraineurs with migraine without aura were pre-treated with 150 mg of prednisolone or placebo followed by a 20-min infusion of GTN (0.5 ug/kg/min). One hour after the GTN-infusion, the participants were sent home, but continued to rate headache and possible associated symptoms by filling out...... a headache diary every hour for 12 h. There were two equal primary efficacy end-points: frequency of delayed migraine and intensity of delayed headache. RESULTS: Nine patients experienced a GTN headache fulfilling the diagnostic criteria for migraine without aura on the placebo day compared with four...

  14. INSULIN INDUCES NITRIC OXIDE PRODUCTION IN BOVINEAORTIC ENDOTHELIAL CELLS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To examine the effects of insulin on cell proliferation, nitric oxide (NO) release and nitric oxide synthase (NOS) gene expression in bovine aortic endothelial cells ( BAEC ) . Methods The mi togenesis was assessed by MTT method; the products of NO in the culture media, by Griess reaction; and the levels of NOS mRNA in BAEC , by RT/PCR tech nique. Results BAEC were not responsive to the growth-promoting effects of insulin. Stimulation with insulin resulted a dose-dependent rise of NO in the culture supernatants 2h later, with a maximum at 12~24h and a decline at 24h. This rise was inhibited by an inhibitor of NOS (L-NAME). NOS mRNA increased slightly in BAEC without statistical significance. Conelu sion The study suggested that the insulin-induced NO release might be caused directly by NOS activation.

  15. Ethanol extracts of Scutellaria baicalensis protect against lipopolysaccharide-induced acute liver injury in mice

    Institute of Scientific and Technical Information of China (English)

    Hai Nguyen Thanh; Hue Pham Thi Minh; Tuan Anh Le; Huong Duong Thi Ly; Tung Nguyen Huu; Loi Vu Duc; Thu Dang Kim; Tung Bui Thanh

    2015-01-01

    To investigated the protective potential of ethanol extracts of Scutellaria baicalensis (S. baicalensis ) against lipopolysaccharide (LPS)-induced liver injury. Methods: Dried roots of S. baicalensis were extracted with ethanol and concentrated to yield a dry residue. Mice were administered 200 mg/kg of the ethanol extracts orally once daily for one week. Animals were subsequently administered a single dose of LPS (5 mg/kg of body weight, intraperitoneal injection). Both protein and mRNA levels of cytokines, such as tumor necrosis factor alpha, interleukin-1β, and interleukin-6 in liver tissues were evaluated by ELISA assay and quantitative PCR. Cyclooxygenase-2, inducible nitric oxide synthase, and nuclear factor-κB protein levels in liver tissues were analyzed by western blotting. Results: Liver injury induced by LPS significantly increased necrosis factor alpha, interleukin-1β, interleukin-6, cyclooxygenase-2, inducible nitric oxide synthase, and nuclear factor-κB in liver tissues. Treatment with ethanol extracts of S. baicalensis prevented all of these observed changes associated with LPS-induced injury in liver mice. Conclusions: Our study showed that S. baicalensis is potentially protective against LPS-induced liver injury in mice.

  16. Ethanol extracts of Scutellaria baicalensis protect against lipopolysaccharide-induced acute liver injury in mice

    Institute of Scientific and Technical Information of China (English)

    Hai; Nguyen; Thanh; Hue; Pham; Thi; Minh; Tuan; Anh; Le; Huong; Duong; Thi; Ly; Tung; Nguyen; Huu; Loi; Vu; Duc; Thu; Dang; Kim; Tung; Bui; Thanh

    2015-01-01

    Objective: To investigated the protective potential of ethanol extracts of Scutellaria baicalensis(S. baicalensis) against lipopolysaccharide(LPS)-induced liver injury. Methods: Dried roots of S. baicalensis were extracted with ethanol and concentrated to yield a dry residue. Mice were administered 200 mg/kg of the ethanol extracts orally once daily for one week. Animals were subsequently administered a single dose of LPS(5 mg/kg of body weight, intraperitoneal injection). Both protein and m RNA levels of cytokines, such as tumor necrosis factor alpha, interleukin-1β, and interleukin-6 in liver tissues were evaluated by ELISA assay and quantitative PCR. C yclooxygenase-2, inducible nitric oxide synthase, and nuclear factor-κB protein levels in liver tissues were analyzed by western blotting. Results: Liver injury induced by LPS signifi cantly increased necrosis factor alpha, interleukin-1β, interleukin-6, cyclooxygenase-2, inducible nitric oxide synthase, and nuclear factor-κB in liver tissues. Treatment with ethanol extracts of S. baicalensis prevented all of these observed changes associated with LPS-induced injury in liver mice.Conclusions: Our study showed that S. baicalensis is potentially protective against LPS-induced liver injury in mice.

  17. Expression of inducible nitric oxide in human lung epithelial cells.

    Science.gov (United States)

    Robbins, R A; Barnes, P J; Springall, D R; Warren, J B; Kwon, O J; Buttery, L D; Wilson, A J; Geller, D A; Polak, J M

    1994-08-30

    Nitric oxide (NO) is increased in the exhaled air of subjects with several airway disorders. To determine if cytokines could stimulate epithelial cells accounting for the increased NO, the capacity of the proinflammatory cytokines (cytomix: tumor necrosis factor-alpha, interleukin-1 beta, and interferon-gamma) to increase inducible nitric oxide synthase (iNOS) was investigated in A549 and primary cultures of human bronchial epithelial cells. Cytomix induced a time-dependent increase in nitrite levels in culture supernatant fluids (p < 0.05). Increased numbers of cells stained for iNOS and increased iNOS mRNA was detected in the cytokine-stimulated cells compared to control (p < 0.05). Dexamethasone diminished the cytokine-induced increase in nitrite, iNOS by immunocytochemistry, and iNOS mRNA. These data demonstrate that cytokines, such as those released by mononuclear cells, can induce lung epithelial iNOS expression and NO release, and that this is attenuated by dexamethasone.

  18. Uridine prevents fenofibrate-induced fatty liver.

    Directory of Open Access Journals (Sweden)

    Thuc T Le

    Full Text Available Uridine, a pyrimidine nucleoside, can modulate liver lipid metabolism although its specific acting targets have not been identified. Using mice with fenofibrate-induced fatty liver as a model system, the effects of uridine on liver lipid metabolism are examined. At a daily dosage of 400 mg/kg, fenofibrate treatment causes reduction of liver NAD(+/NADH ratio, induces hyper-acetylation of peroxisomal bifunctional enzyme (ECHD and acyl-CoA oxidase 1 (ACOX1, and induces excessive accumulation of long chain fatty acids (LCFA and very long chain fatty acids (VLCFA. Uridine co-administration at a daily dosage of 400 mg/kg raises NAD(+/NADH ratio, inhibits fenofibrate-induced hyper-acetylation of ECHD, ACOX1, and reduces accumulation of LCFA and VLCFA. Our data indicates a therapeutic potential for uridine co-administration to prevent fenofibrate-induced fatty liver.

  19. Interleukin 1 beta induces diabetes and fever in normal rats by nitric oxide via induction of different nitric oxide synthases

    DEFF Research Database (Denmark)

    Reimers, J I; Bjerre, U; Mandrup-Poulsen, T

    1994-01-01

    Substantial in vitro evidence suggests that nitric oxide may be a major mediator of interleukin 1 (IL-1) induced pancreatic beta-cell inhibition and destruction in the initial events leading to insulin-dependent diabetes mellitus. Using NG-nitro-L-arginine methyl ester, an inhibitor of both......, glucagon, corticosterone and leukocyte- and differential-counts in normal rats injected once daily for 5 days with interleukin 1 beta (IL-1 beta) (0.8 microgram/rat = 4.0 micrograms/kg). Inhibition of both the constitutive and the inducible forms of nitric oxide synthase prevented IL-1 beta-induced fever...

  20. Nebivolol and chrysin protect the liver against ischemia/reperfusion-induced injury in rats

    Directory of Open Access Journals (Sweden)

    Sayed M. Mizar

    2015-03-01

    Full Text Available Oxidative stress plays a key role in the pathogenesis of hepatic ischemia/reperfusion (I/R-induced injury, one of the leading causes of liver damage post-surgical intervention, trauma and transplantation. This study aimed to evaluate the protective effect of nebivolol and chrysin against I/R-induced liver injury via their vasodilator and antioxidant effects, respectively. Adult male Wister rats received nebivolol (5 mg/kg and/or chrysin (25 mg/kg by oral gavage daily for one week then subjected to ischemia via clamping the portal triad for 30 min then reperfusion for 30 min. Liver function enzymes, alanine transaminase (ALT and aspartate transaminase (AST, as well as hepatic Myeloperoxidase (MPO, total nitrate (NOx, glutathione (GSH and liver malondialdehyde (MDA were measured at the end of the experiment. Liver tissue damage was examined by histopathology. In addition, the expression levels of nitric oxide synthase (NOS subtypes, endothelial (eNOS and inducible (iNOS in liver samples were assessed by Western blotting and confirmed by immunohistochemical analysis. Both chrysin and nebivolol significantly counteracted I/R-induced oxidative stress and tissue damage biomarkers. The combination of these agents caused additive liver protective effect against I/R-induced damage via the up regulation of nitric oxide expression and the suppression of oxidative stress. Chrysin and nebivolol combination showed a promising protective effect against I/R-induced liver injury, at least in part, via decreasing oxidative stress and increasing nitric oxide levels.

  1. Concentrations of Nitric Oxide in Rat Brain Tissues after Diffuse Brain Injury and Neuroprotection by the Selective Inducible Nitric Oxide Synthase Inhibitor Aminoguanidine

    Institute of Scientific and Technical Information of China (English)

    Yi-bao Wang; Shao-wu Ou; Guang-yu Li; Yun-hui Liu

    2005-01-01

    @@ To investigate the effects of nitric oxide (NO) and the selective inducible nitric oxide synthase (iNOS) inhibitor aminoguanidine (AG) on trauma, we explored the concentrations of nitric oxide in rat brain tissues at different time stamps after diffuse brain injury (DBI) with or without AG treatment.

  2. Inducible nitric oxide synthase is responsible for nitric oxide release from murine pituicytes

    DEFF Research Database (Denmark)

    Kjeldsen, T H; Rivier, C; Lee, S;

    2003-01-01

    This study investigated whether pituicytes were able to produce and release nitric oxide (NO), and which type of nitric oxide synthase (NOS) would be responsible for this phenomenon. Lipopolysaccharide (LPS) 1 micro g/ml was used as inflammatory mediator. Because pituicytes are known to secrete...

  3. Sequential changes in redox status and nitric oxide synthases expression in the liver after bile duct ligation.

    Science.gov (United States)

    Vázquez-Gil, M José; Mesonero, M José; Flores, Olga; Criado, Manuela; Hidalgo, Froilán; Arévalo, Miguel A; Sánchez-Rodríguez, Angel; Tuñón, M Jesús; López-Novoa, José M; Esteller, A

    2004-06-25

    Bile duct ligation (BDL) in rats induces portal fibrosis. This process has been linked to changes in the oxidative state of the hepatic cells and in the production of nitric oxide. Our objective was to find possible temporal connections between hepatic redox state, NO synthesis and liver injury. In this work we have characterized hepatic lesions 17 and 31 days after BDL and determined changes in hepatic function, oxidative state, and NO production. We have also analyzed the expression and localization of inducible NO synthase (NOS2) and constitutive NO synthase (NOS3). After 17 and 31 days from ligature, lipid peroxidation is increased and both plasma concentration and biliary excretion of nitrite+nitrate are rised. 17 days after BDL both NOS2 and NOS3 are expressed intensely and in the same regions. 31 days after BDL, the expression of NOS2 remains elevated and is localized mostly in preserved hepatocytes in portal areas and in neighborhoods of centrolobulillar vein. NOS3 is localized in vascular regions of portal spaces and centrolobulillar veins and in preserved sinusoids and although its expression is greater than in control animals (34%), it is clearly lower (50%) than 17 days after BDL. The time after BDL is crucial in the study of NO production, intrahepatic localization of NOS isoforms expression, and cell type involved, since all these parameters change with time. BDL-induced, peroxidation and fibrosis are not ligated by a cause-effect relationship, but rather they both seem to be the consequence of common inductors.

  4. Drug –induced liver injury:a review

    OpenAIRE

    Sreya Kosanam; Revathi Boyina; Lakshmi Prasanthi N

    2015-01-01

    The incidence of drug induced liver injury (DILI) is about 1/1000 to 1/10000 among patients who receive therapeutic drug doses. Drug induced hepatotoxicity is a major cause of acute and chronic liver disease. The severity of liver damage ranges from nonspecific changes in liver structure to acute liver failure, cirrhosis and liver cancer. Some common agents that can cause liver injury are acetaminophen, antibiotics, statins, INH and herbal drugs.Drug-induced hepatotoxicity can be categorized ...

  5. Inhibition of diethylnitrosamine-induced liver cancer in rats by Rhizoma paridis saponin.

    Science.gov (United States)

    Liu, Jing; Man, Shuli; Li, Jing; Zhang, Yang; Meng, Xin; Gao, Wenyuan

    2016-09-01

    Rhizoma Paridis saponin (RPS) had been regarded as the main active components responsible for the anti-tumor effects of the herb Paris polyphylla var. yunnanensis (Franch.) Hand.-Mazz. In the present research, we set up a rat model of diethylnitrosamine (DEN) induced hepatoma to evaluate antitumor effect of RPS. After 20 weeks treatment, rats were sacrificed to perform histopathological examinations, liver function tests, oxidative stress assays and so forth. As a result, DEN-induced hepatoma formation. RPS alleviated levels of liver injury through inhibiting liver tissues of malondialdehyde (MDA) and nitric oxide (NO) formation, increasing superoxide dismutases (SOD) production, and up-regulating expression of GST-α/μ/π in DEN-induced rats. All in all, RPS would be a potent agent inhibiting chemically induced liver cancer in the prospective application.

  6. [Interrupted alcohol treatment and liver: free radical homeostasis, nitric oxide, adaptive mechanisms].

    Science.gov (United States)

    Miskevich, D A; Borodinskiĭ, A N; Petushok, N E; Konovalenko, O V; Lelevich, V V

    2006-01-01

    Alcohol administration can result in liver damage. Reactive oxygen species (ROS), nitric oxide (NO) and their interaction are crucial factors in this process. The aim of work was to investigate, free radical state and mechanisms of adaptation of the antioxidant system (AOS) to stress, caused by interrupted alcohol intake. Repeated cycles of alcoholization caused an imbalance between production and utilization of various ROS. This imbalance was due to impairments in the system superoxide dismutase/catalase. Nevertheless, in most experimental groups there was clear reduction of lipid peroxidation (LPO) products evaluated by thiobarbituric acid reactive substances. This might be attributed to the antioxidant effect of NO. However, there was an increased level of transaminases in blood plasma. After 28 days of this experimental scheme all the parameters studied normalized.

  7. Nitric Oxide Signaling in Hypergravity-Induced Neuronal Plasticity

    Science.gov (United States)

    Holstein, Gay R.

    2003-01-01

    The goal of this research project was to identify the neurons and circuits in the vestibular nuclei and nucleus prepositus hypoglossi that utilize nitric oxide (NO) for intercellular signaling during gravity-induced plasticity. This objective was pursued using histochemical and immunocytochemical approaches to localize NO-producing neurons and characterize the fine morphology of the cells in ground-based studies of normal rats, rats adapted to hypergravity, and rats adapted to hypergravity and then re-adapted to the 1G environment. NO-producing neurons were identified and studied using four methodologies: i) immunocytochemistry employing polyclonal antibodies directed against neuronal nitric oxide synthase (nNOS), to provide an indication of the capacity of a cell for NO production; ii) immunocytochemistry employing a monoclonal antibody directed against L-citrulline, to provide an indirect index of the enzyme's activity; iii) histochemistry based on the NADPH-diaphorase reaction, for fuI1 cytological visualization of neurons; and iv) double immunofluorescence to co-localize nNOS and L-citrulline in individual vestibular nuclei (VN) and neurons.

  8. Mechanism of inducible nitric oxide synthase exclusion from mycobacterial phagosomes.

    Directory of Open Access Journals (Sweden)

    Alexander S Davis

    2007-12-01

    Full Text Available Mycobacterium tuberculosis is sensitive to nitric oxide generated by inducible nitric oxide synthase (iNOS. Consequently, to ensure its survival in macrophages, M. tuberculosis inhibits iNOS recruitment to its phagosome by an unknown mechanism. Here we report the mechanism underlying this process, whereby mycobacteria affect the scaffolding protein EBP50, which normally binds to iNOS and links it to the actin cytoskeleton. Phagosomes harboring live mycobacteria showed reduced capacity to retain EBP50, consistent with lower iNOS recruitment. EBP50 was found on purified phagosomes, and its expression increased upon macrophage activation, paralleling expression changes seen with iNOS. Overexpression of EBP50 increased while EBP50 knockdown decreased iNOS recruitment to phagosomes. Knockdown of EBP50 enhanced mycobacterial survival in activated macrophages. We tested another actin organizer, coronin-1, implicated in mycobacterium-macrophage interaction for contribution to iNOS exclusion. A knockdown of coronin-1 resulted in increased iNOS recruitment to model latex bead phagosomes but did not increase iNOS recruitment to phagosomes with live mycobacteria and did not affect mycobacterial survival. Our findings are consistent with a model for the block in iNOS association with mycobacterial phagosomes as a mechanism dependent primarily on reduced EBP50 recruitment.

  9. Hepatoprotective Effect of Citral on Acetaminophen-Induced Liver Toxicity in Mice

    Science.gov (United States)

    Silva-Filho, Saulo Euclides; Cardia, Gabriel Fernando Esteves; Cremer, Edivaldo; Bersani-Amado, Ciomar Aparecida

    2017-01-01

    High doses of acetaminophen (APAP) lead to acute liver damage. In this study, we evaluated the effects of citral in a murine model of hepatotoxicity induced by APAP. The liver function markers alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transferase (γGT) were determined to evaluate the hepatoprotective effects of citral. The livers were used to determine myeloperoxidase (MPO) activity and nitric oxide (NO) production and in histological analysis. The effect of citral on leukocyte migration and antioxidant activity was evaluated in vitro. Citral pretreatment decreased significantly the levels of ALT, AST, ALP, and γGT, MPO activity, and NO production. The histopathological analysis showed an improvement of hepatic lesions in mice after citral pretreatment. Citral inhibited neutrophil migration and exhibited antioxidant activity. Our results suggest that citral protects the liver against liver toxicity induced by APAP. PMID:28717379

  10. Hydroxycut-induced Liver Toxicity

    African Journals Online (AJOL)

    hanumantp

    Keywords: Hydroxycut, Liver toxicity, Nutritional supplements. Access this article ... presumed notion of safety with over the counter and so called natural weight ... increasing basal metabolic rate and decreasing total body fat. However, there ...

  11. The Successful Use of Inhaled Nitric Oxide in the Management of Severe Hepatopulmonary Syndrome after Orthotopic Liver Transplantation

    Directory of Open Access Journals (Sweden)

    Joshua Santos

    2014-01-01

    Full Text Available Hepatopulmonary syndrome (HPS is characterized by pulmonary vasodilation and subsequent hypoxemia in the setting of hepatic dysfunction. There is currently no pharmacologic intervention that has been shown to significantly affect outcomes and liver transplantation remains the mainstay of therapy. Unfortunately, patients undergoing liver transplantation are at high risk of significant hypoxemia and mortality in the early postoperative period. In the following case series, we present two cases of patients with severe HPS who underwent liver transplantation and experienced marked hypoxemia in the early postoperative period. In both cases, we successfully treated the patients with inhaled nitric oxide for their severe refractory life-threatening hypoxemia which led to immediate and dramatic improvements in their oxygenation. Although the use of inhaled nitric oxide in patients with HPS has been sporadically reported in pediatric literature and in animal studies, to our knowledge, our cases are the first recorded in adult patients.

  12. Regulation of prostaglandin generation in carrageenan-induced pleurisy by inducible nitric oxide synthase in knockout mice.

    NARCIS (Netherlands)

    Rossi, A.; Cuzzocrea, S.; Mazzon, E.; Serraino, I.; Sarro, A. de; Dugo, L.; Felice, M.R.; Loo, F.A.J. van de; Rosa, M. Di; Musci, G.; Caputi, A.P.; Sautebin, L.

    2003-01-01

    In the present study, by comparing the responses in wild-type mice (iNOSWT) and mice lacking (iNOSKO) the inducible (or type 2) nitric oxide synthase (iNOS), we investigated the correlation between endogenous nitric oxide (NO) and prostaglandin (PG) generation in carrageenan-induced pleurisy. The

  13. Regulation of prostaglandin generation in carrageenan-induced pleurisy by inducible nitric oxide synthase in knockout mice.

    NARCIS (Netherlands)

    Rossi, A.; Cuzzocrea, S.; Mazzon, E.; Serraino, I.; Sarro, A. de; Dugo, L.; Felice, M.R.; Loo, F.A.J. van de; Rosa, M. Di; Musci, G.; Caputi, A.P.; Sautebin, L.

    2003-01-01

    In the present study, by comparing the responses in wild-type mice (iNOSWT) and mice lacking (iNOSKO) the inducible (or type 2) nitric oxide synthase (iNOS), we investigated the correlation between endogenous nitric oxide (NO) and prostaglandin (PG) generation in carrageenan-induced pleurisy. The in

  14. Nitric oxide synthase is induced in sporulation of Physarum polycephalum

    Science.gov (United States)

    Golderer, Georg; Werner, Ernst R.; Leitner, Stefan; Gröbner, Peter; Werner-Felmayer, Gabriele

    2001-01-01

    The myxomycete Physarum polycephalum expresses a calcium-independent nitric oxide (NO) synthase (NOS) resembling the inducible NOS isoenzyme in mammals. We have now cloned and sequenced this, the first nonanimal NOS to be identified, showing that it shares Physarum macroplasmodia during the 5-day starvation period needed to induce sporulation competence. Induction of both NOS and sporulation competence were inhibited by glucose, a growth signal and known repressor of sporulation, and by l-N6–(1-iminoethyl)-lysine (NIL), an inhibitor of inducible NOS. Sporulation, which is triggered after the starvation period by light exposure, was also prevented by 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ), an inhibitor of NO-sensitive guanylate cyclase. In addition, also expression of lig1, a sporulation-specific gene, was strongly attenuated by NIL or ODQ. 8-Bromo-cGMP, added 2 h before the light exposure, restored the capacity of NIL-treated macroplasmodia to express lig1 and to sporulate. This indicates that the second messenger used for NO signaling in sporulation of Physarum is cGMP and links this signaling pathway to expression of lig1. PMID:11358872

  15. Effects of glucocorticoid dexamethasone on serum nitric oxide synthase activity and nitric oxide levels in a rat model of lung disease-induced brain injury

    Institute of Scientific and Technical Information of China (English)

    Huajun Li; Ligang Jiang; Meng Xia; Haiping Li; Fanhua Meng; Wei Li; Lifeng Liu; Zhaohui Wang

    2011-01-01

    In this study, we investigated the effects of dexamethasone, pertussis toxin (a Gi protein inhibitor), and actinomycin (a transcription inhibitor) on serum nitric oxide synthase activity and nitric oxide content in a rat model of lung disease-induced brain injury. High-dose dexamethasone (13 mg/kg) and dexamethasone + actinomycin reduced lung water content, increased serum nitric oxide synthase activity and nitric oxide content, diminished inflammatory cell infiltration in pulmonary alveolar interstitium, attenuated meningeal vascular hyperemia, reduced glial cell infiltration, and decreased cerebral edema. These results demonstrate that high-dose glucocorticoid treatment can reduce the severity of lung disease-induced brain injury by increasing nitric oxide synthase activity and nitric oxide levels.

  16. Cerebral ischemia—induced neuronal apoptosis mediated by nitric oxide

    Institute of Scientific and Technical Information of China (English)

    NomuY

    2002-01-01

    To elucidate the cellular and molecular mechanism of cerebral ischemia-induced neuronal apoptosis mediated by nitric oxide (NO) in the brain,we investigated:(1)cell death in hippocampal CA1 neurons of rats after a rransient four vessel occlusion (4VO)/reperfusion and (2) apoptosis induced by NOC18(NO releaser) using SHSY5Y cells,a human neuroblastoma cell line.We found that 4VO caused expression of inducible type of NO synthase (iNOS) in glial cells and neuronal apoptosis in CA1 region of rats.Next we examined in vitro apoptotic effects of NOC18 on SHSY5Y cells and suggest that NO decrease mitochondrial membrane potential,release cytochrome C from mitochondria,activates caspase-3,degrade inhibitor of caspase-activated DNase(Icad),and activated DNase translocate into nucleus and induce DNA fragmentation.Thus we conclude that the excess amount of NO produced by glial iNOS at cerebral ischemia could be involved in neuronal apoptosis in CA1 region.Regarding NO action on neurons,we further obtained that NO propects neuronal apoptosis in PC12 cells perhaps by nitrosylation of caspase,subsequent reduction of proteolytic activity.Taken together,we suggest that NO seem to exert dual effects(toxic and beneficial) on neuronal apoptosis,the one (toxic);apoptosis-induction throuth the decrease in mitochondrial membrane potentials and cytochrome C release and the othe (beneficial);protection against apoptosis through the inhibition of caspase activity.

  17. Predictive value of exhaled nitric oxide and aerobic capacity for sepsis complications after liver transplantation.

    Science.gov (United States)

    Neviere, Remi; Trinh-Duc, Pierre; Hulo, Sébastien; Edme, Jean Louis; Dehon, Aurélie; Boleslawski, Emmanuel; Dharancy, Sébastien; Lebuffe, Gilles

    2016-12-01

    Our objective was to investigate the predictive value of fractional nitric oxide (NO) concentration in exhaled breath (FeNO) and aerobic capacity (peak VO2 ) for postoperative sepsis in liver transplantation candidates. Patients were identified and charts of all consecutive patients were prospectively reviewed. Bacterial sepsis represented the commonest postoperative complications (30%), which was attributed to peritonitis, pneumonia, and catheter-related infections. Preoperative FeNO and peak VO2 values were lower in patients with postoperative sepsis. Patients with sepsis required higher needs for mechanical ventilation and ICU length of stay. Inverse correlation was found between logarithmically FeNO-transformed data and systolic pulmonary artery pressure (r = -0.348; P = 0.018). Multivariate analyses using bootstrap sampling method indicated that odds of sepsis were associated with lower values of peak exercise VO2 [OR = 0.790 (0.592; 0.925)] and reduced log(FeNo) [OR = 0.027 (0.001; 0.451)], but not with higher MELD scores [OR = 1.141 (0.970; 1.486)]. By evaluating the cutoff for the ROC curves in each bootstrap resampling, median and 95% confidence interval were calculated for peak VO2 : 17 [16.2; 22] ml/kg/min and FeNO: 17.2 [13.0; 33.9] ppb. We conclude that low peak exercise VO2 and reduced FeNO may help identify patients who are at risk to develop perioperative sepsis. © 2016 Steunstichting ESOT.

  18. Citrus nobiletin suppresses inducible nitric oxide synthase gene expression in interleukin-1β-treated hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Yoshigai, Emi [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan); Ritsumeikan Global Innovation Research Organization (R-GIRO), Kusatsu, Shiga (Japan); Machida, Toru [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan); Okuyama, Tetsuya [Ritsumeikan Global Innovation Research Organization (R-GIRO), Kusatsu, Shiga (Japan); Mori, Masatoshi; Murase, Hiromitsu; Yamanishi, Ryota [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan); Okumura, Tadayoshi [Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga (Japan); Department of Surgery, Kansai Medical University, Hirakata, Osaka (Japan); Ikeya, Yukinobu [Department of Pharmacy, College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, Shiga (Japan); Nishino, Hoyoku [Ritsumeikan Global Innovation Research Organization (R-GIRO), Kusatsu, Shiga (Japan); Department of Biochemistry, Kyoto Prefectural University of Medicine, Kyoto (Japan); Nishizawa, Mikio, E-mail: nishizaw@sk.ritsumei.ac.jp [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan)

    2013-09-13

    Highlights: •Nobiletin is a polymethoxylated flavone that is abundant in citrus peels. •Nobiletin is a major constituent of the Citrus unshiu peel extract. •Nobiletin suppresses induction of NO and reduces iNOS expression in hepatocytes. •Nobiletin reduces the iNOS promoter activity and the DNA-binding activity of NF-κB. -- Abstract: Background: Nobiletin is a polymethoxylated flavone that is abundant in the peels of citrus fruits, such as Citrus unshiu (Satsuma mandarin) and Citrus sinensis. The dried peels of C. unshiu (chinpi) have been included in several formulae of Japanese Kampo medicines. Nobiletin may suppress the induction of inducible nitric oxide synthase (iNOS), which synthesizes the inflammatory mediator nitric oxide (NO) in hepatocytes. Methods: A C. unshiu peel (CUP) extract was prepared. Primary cultured rat hepatocytes were treated with the CUP extract or nobiletin in the presence of interleukin 1β (IL-1β), which induces iNOS expression. NO production and iNOS gene expression were analyzed. Results: High-performance liquid chromatography analyses revealed that the nobiletin content in the CUP extract was 0.14%. Nobiletin dose-dependently reduced the NO levels and decreased iNOS expression at the protein, mRNA and antisense transcript levels. Flavone, which does not contain any methoxy groups, also suppressed iNOS induction. Nobiletin reduced the transcriptional activity of iNOS promoter-luciferase constructs and the DNA-binding activity of nuclear factor κB (NF-κB) in the nuclei. Conclusions: The suppression of iNOS induction by nobiletin suggests that nobiletin may be responsible for the anti-inflammatory effects of citrus peels and have a therapeutic potential for liver diseases.

  19. Inducible nitric oxide synthase is expressed in synovial fluid granulocytes.

    Science.gov (United States)

    Cedergren, J; Forslund, T; Sundqvist, T; Skogh, T

    2002-10-01

    The objective of the study was to evaluate the NO-producing potential of synovial fluid (SF) cells. SF from 15 patients with arthritis was compared with blood from the same individuals and with blood from 10 healthy controls. Cellular expression of inducible nitric oxide synthase (iNOS) was analysed by flow cytometry. High-performance liquid chromatography was used to measure l-arginine and l-citrulline. Nitrite and nitrate were measured colourimetrically utilizing the Griess' reaction. Compared to whole blood granulocytes in patients with chronic arthritis, a prominent iNOS expression was observed in SF granulocytes (P < 0.001). A slight, but statistically significant, increase in iNOS expression was also recorded in lymphocytes and monocytes from SF. l-arginine was elevated in SF compared to serum (257 +/- 78 versus 176 +/- 65 micro mol/l, P = 0.008), whereas a slight increase in l-citrulline (33 +/- 11 versus 26 +/- 9 micro mol/l), did not reach statistical significance. Great variations but no significant differences were observed comparing serum and SF levels of nitrite and nitrate, respectively, although the sum of nitrite and nitrate tended to be elevated in SF (19.2 +/- 20.7 versus 8.6 +/- 6.5 micro mol/l, P = 0.054). Synovial fluid leucocytes, in particular granulocytes, express iNOS and may thus contribute to intra-articular NO production in arthritis.

  20. Evaluation of Nitric Oxide (NO Levels in Hepatitis C Virus (HCV Infection: Relationship to Schistosomiasis and Liver Cirrhosis among Egyptian Patients

    Directory of Open Access Journals (Sweden)

    Mahmoud Ismail Hassan

    2002-01-01

    Full Text Available Nitric oxide (NO, a recently discovered free radical, is overproduced in liver cirrhosis. Hepatitis C virus (HCV might increase NO levels via increased inducible NO synthase (iNOS. This work was carried out to study the effect of HCV-induced liver cirrhosis on NO levels among Egyptian patients. The study included 46 patients with liver cirrhosis, and 30 healthy individuals of matched age and sex. NO levels determined as the stable endproduct nitrate, showed a statistically significant increase among patients compared to the control group (P < 0.001. Furthermore, NO levels increased proportionally with the severity of liver cirrhosis as assessed by Child’s classification (P < 0.05. Moreover, schistosomial infection enhanced NO levels in cirrhotic patients with HCV infection compared to non-bilharzial patients (P < 0.001. Polymerase chain reaction (PCR and branched DNA assays were used for detection of HCV RNA positivity, and measurement of the virus load, respectively. Both showed a positive correlation with the NO levels (P < 0.001. At a nitrate cutoff value of 70 μmol/L, the sensitivity and specificity were 83.0% and 37.0% respectively. Chi square analysis showed a significant correlation between ALT levels and both HCV RNA positivity by polymerase chain reaction (PCR (P < 0.02, and virus load (P < 0.05. Interestingly enough, there was a significant positive correlation between HCV RNA and schistosomal antibody titer as measured by hemaglutination inhibition assay (HAI (P < 0.05. The data presented in this report indicated an association between NO levels and the development and progression of liver cirrhosis. Furthermore, the findings obtained from this study demonstrated that schistomiasis is an important risk factor involved in enhancement of NO levels and virus replication. The latter may aggravate liver cell injury and hence the development of cirrhosis.

  1. Evaluation of Nitric Oxide (NO) Levels in Hepatitis C Virus (HCV) Infection: Relationship to Schistosomiasis and Liver Cirrhosis among Egyptian Patients

    Science.gov (United States)

    Hassan, Mahmoud Ismail; Kassim, Samar Kamal; Ali, Hebatalla Said; Sayed, El-Dieb Abd ElSattar; Khalifa, Ali

    2002-01-01

    Nitric oxide (NO), a recently discovered free radical, is overproduced in liver cirrhosis. Hepatitis C virus (HCV) might increase NO levels via increased inducible NO synthase (iNOS). This work was carried out to study the effect of HCV-induced liver cirrhosis on NO levels among Egyptian patients. The study included 46 patients with liver cirrhosis, and 30 healthy individuals of matched age and sex. NO levels determined as the stable endproduct nitrate, showed a statistically significant increase among patients compared to the control group (P < 0.001). Furthermore, NO levels increased proportionally with the severity of liver cirrhosis as assessed by Child’s classification (P < 0.05). Moreover, schistosomial infection enhanced NO levels in cirrhotic patients with HCV infection compared to non-bilharzial patients (P < 0.001). Polymerase chain reaction (PCR) and branched DNA assays were used for detection of HCV RNA positivity, and measurement of the virus load, respectively. Both showed a positive correlation with the NO levels (P < 0.001). At a nitrate cutoff value of 70 μmol/L, the sensitivity and specificity were 83.0% and 37.0% respectively. Chi square analysis showed a significant correlation between ALT levels and both HCV RNA positivity by polymerase chain reaction (PCR) (P < 0.02), and virus load (P < 0.05). Interestingly enough, there was a significant positive correlation between HCV RNA and schistosomal antibody titer as measured by hemaglutination inhibition assay (HAI) (P < 0.05). The data presented in this report indicated an association between NO levels and the development and progression of liver cirrhosis. Furthermore, the findings obtained from this study demonstrated that schistomiasis is an important risk factor involved in enhancement of NO levels and virus replication. The latter may aggravate liver cell injury and hence the development of cirrhosis. PMID:12515909

  2. Role of neuronal nitric oxide synthase and inducible nitric oxide synthase in intestinal injury in neonatal rats

    Institute of Scientific and Technical Information of China (English)

    Hui LU; Bing Zhu; Xin-Dong Xue

    2006-01-01

    AIM: To investigate the dynamic change and role of neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) in neonatal rat with intestinal injury and to define whether necrotizing enterocolitis (NEC) is associated with the levels of nitric oxide synthase (NOS) in the mucosa of the affected intestine tissue.METHODS: Wistar rats less than 24 h in age received an intraperitoneal injection with 5 mg/kg lipopolysaccharide (LPS). Ileum tissues were collected at 1, 3, 6, 12 and 24 h following LPS challenge for histological evaluation of NEC and for measurements of nNOS and iNOS. The correlation between the degree of intestinal injury and levels of NOS was determined.RESULTS: The LPS-injected pups showed a significant increase in injury scores versus the control. The expression of nNOS protein and mRNA was diminished after LPS injection. There was a negative significant correlation between the nNOS protein and the grade of median intestinal injury within 24 h. The expression of iNOS protein and mRNA was significantly increased in the peak of intestinal injury.CONCLUSION: nNOS and iNOS play different roles in LPS-induced intestinal injury. Caution should be exerted concerning potential therapeutic uses of NOS inhibitors in NEC.

  3. Role of inducible nitric oxide synthase pathway on methotrexate-induced intestinal mucositis in rodents

    Directory of Open Access Journals (Sweden)

    Siqueira Francisco JWS

    2011-08-01

    Full Text Available Abstract Background Methotrexate treatment has been associated to intestinal epithelial damage. Studies have suggested an important role of nitric oxide in such injury. The aim of this study was to investigate the role of nitric oxide (NO, specifically iNOS on the pathogenesis of methotrexate (MTX-induced intestinal mucositis. Methods Intestinal mucositis was carried out by three subcutaneous MTX injections (2.5 mg/kg in Wistar rats and in inducible nitric oxide synthase knock-out (iNOS-/- and wild-type (iNOS+/+ mice. Rats were treated intraperitoneally with the NOS inhibitors aminoguanidine (AG; 10 mg/Kg or L-NAME (20 mg/Kg, one hour before MTX injection and daily until sacrifice, on the fifth day. The jejunum was harvested to investigate the expression of Ki67, iNOS and nitrotyrosine by immunohistochemistry and cell death by TUNEL. The neutrophil activity by myeloperoxidase (MPO assay was performed in the three small intestine segments. Results AG and L-NAME significantly reduced villus and crypt damages, inflammatory alterations, cell death, MPO activity, and nitrotyrosine immunostaining due to MTX challenge. The treatment with AG, but not L-NAME, prevented the inhibitory effect of MTX on cell proliferation. MTX induced increased expression of iNOS detected by immunohistochemistry. MTX did not cause significant inflammation in the iNOS-/- mice. Conclusion These results suggest an important role of NO, via activation of iNOS, in the pathogenesis of intestinal mucositis.

  4. Inhibition of lipopolysaccharide-induced nitric oxide and prostaglandin E2 production by chloroform fraction of Cudrania tricuspidata in RAW 264.7 macrophages

    OpenAIRE

    Yang Gabsik; Lee Kyungjin; Lee Mihwa; Ham Inhye; Choi Ho-Young

    2012-01-01

    Abstract Background Cudrania tricuspidata extract is an important traditional herbal remedy for tumors, inflammation, gastritis, and liver damage and is predominantly used in Korea, China, and Japan. However, the anti-inflammatory effects of the extract have not yet been conclusively proved. Methods In this study, we investigated the effects of the CHCl3 fraction (CTC) of a methanol extract of C. tricuspidata on the lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin E2 (PGE2...

  5. Effects of Nephritis No. 3 Recipe on Nitric Oxide, Nitric Oxide Synthase Secreted by Cultured Mesangial Cells in Rats and the Gene Expression of Inducible Nitric Oxide Synthase

    Institute of Scientific and Technical Information of China (English)

    陈志强; 黄怀鹏; 黄文政; 朱小棣; 林清棋

    2003-01-01

    Objective: To explore the effect of the Nephritis No. 3 (N-3) recipe on nitric oxide (NO),nitric oxide synthase (NOS) secreted by cultured mesangial cells (MC) and its gene expression of the inducible nitric oxide synthase (iNOS). Methods: The drug (nephritis No. 3)-containing serum was prepared with serum pharmacological technique, and then was applied to react on mesangial cells cultured in fetal calf serum (FCS) and cells cultured in FCS plus lipopolysaccharide. To observe the secretion of NO and NOS and the gene expression of iNOS by means of RT-PCR. Results: Under the two kinds of culture conditions, the content of NO and NOS in the groups with drug-containing serum were higher than those without drug-containing serum (P<0.05, P<0.01), and the expression of iNOS mRNA was up-regulated too. Conclusion: The N-3 could significantly promote the secretion of NO and NOS and the mRNA expression of iNOS in rats.

  6. Inorganic polyphosphate suppresses lipopolysaccharide-induced inducible nitric oxide synthase (iNOS expression in macrophages.

    Directory of Open Access Journals (Sweden)

    Kana Harada

    Full Text Available In response to infection, macrophages produce a series of inflammatory mediators, including nitric oxide (NO, to eliminate pathogens. The production of these molecules is tightly regulated via various mechanisms, as excessive responses are often detrimental to host tissues. Here, we report that inorganic polyphosphate [poly(P], a linear polymer of orthophosphate ubiquitously found in mammalian cells, suppresses inducible nitric oxide synthase (iNOS expression induced by lipopolysaccharide (LPS, a cell wall component of Gram-negative bacteria, in mouse peritoneal macrophages. Poly(P with longer chains is more potent than those with shorter chains in suppressing LPS-induced iNOS expression. In addition, poly(P decreased LPS-induced NO release. Moreover, poly(P suppressed iNOS mRNA expression induced by LPS stimulation, thereby indicating that poly(P reduces LPS-induced iNOS expression by down-regulation at the mRNA level. In contrast, poly(P did not affect the LPS-induced release of TNF, another inflammatory mediator. Poly(P may serve as a regulatory factor of innate immunity by modulating iNOS expression in macrophages.

  7. Impact of venous systemic oxygen persufflation supplemented with nitric oxide gas on cold-stored, warm ischemia-damaged experimental liver grafts.

    Science.gov (United States)

    Srinivasan, Pramod Kadaba; Yagi, Shintaro; Doorschodt, Benedict; Nagai, Kazuyuki; Afify, Mamdouh; Uemoto, Shinji; Tolba, Rene

    2012-02-01

    The increasing shortage of donor organs has led to the increasing use of organs from non-heart-beating donors. We aimed to assess the impact of venous systemic oxygen persufflation (VSOP) supplemented with nitric oxide (NO) gas during the cold storage (CS) of warm ischemia (WI)-damaged experimental liver grafts. Rat livers (n = 5 per group) were retrieved after 30 minutes of WI induced by cardiac arrest (the WI group) and were thereafter preserved for 24 hours by CS in histidine tryptophan ketoglutarate solution. During CS, gaseous oxygen was insufflated via the caval vein with 40 ppm NO (the VSOP-NO group) or without NO (the VSOP group). Cold-stored livers without WI served as controls. Liver viability was assessed after the preservation period by normothermic isolated reperfusion for 45 minutes with oxygenated Krebs-Henseleit buffer. After 45 minutes of reperfusion, the VSOP-NO-treated livers showed significantly lower alanine aminotransferase values than the WI-damaged livers (10.2 ± 0.2 versus 78.2 ± 14.6 IU/L), whereas the control livers showed no differences from the VSOP-NO-treated livers. The mitochondrial enzyme release was lower in the VSOP-NO group (4.0 ± 0.7 IU/L) versus the WI group (18.2 ± 4.9 IU/L). An increased portal vein pressure was observed throughout reperfusion (45 minutes) in the WI group (21.7 ± 0.2 mm Hg) versus the VSOP-NO group (12.2 ± 0.8 mm Hg) and the control group (19.9 ± 0.4 mm Hg). Furthermore, the NO concentration in the perfusate after 5 minutes of reperfusion was highest in the VSOP-NO group. The release of malondialdehyde into the perfusate was significantly reduced in the VSOP-NO group (0.9 ± 0.1 nmol/mL) versus the WI group (31.3 ± 5.3 nmol/mL). In conclusion, the resuscitation of livers after 30 minutes of WI to a level comparable to that of nonischemically damaged livers is possible with VSOP supplemented with NO gas. Moreover, the application of VSOP with NO minimizes the extent of injuries caused by oxygen free

  8. Oxidative stress modulation by Rosmarinus officinalis in CCl4-induced liver cirrhosis.

    Science.gov (United States)

    Gutiérrez, Rosalinda; Alvarado, José L; Presno, Manuel; Pérez-Veyna, Oscar; Serrano, Carmen J; Yahuaca, Patricia

    2010-04-01

    Rosmarinus officinalis (Lamiaceae) possesses antioxidant activity and hepatoprotective effects, and so may provide a possible therapeutic alternative for chronic liver disease. The effect produced by a methanolic extract of Rosmarinus officinalis on CCl(4)-induced liver cirrhosis in rats was investigated using both prevention and reversion models. Over the course of the development of cirrhosis, the increased enzymatic activities of gamma-glutamyl transpeptidase and alanine aminotransferase, and the rise in bilirubin levels caused by CCl(4) administration, were prevented by Rosmarinus officinalis co-administration. When the cirrhosis by oxidative stress was evaluated as an increase on liver lipoperoxidation, total lipid peroxides, nitric oxide in serum, and loss of erythrocyte plasma membrane stability, R. officinalis was shown to prevent such alterations. On cirrhotic animals treated with CCl(4), histological studies showed massive necrosis, periportal inflammation and fibrosis which were modified by R. officinalis. These benefits on experimental cirrhosis suggest a potential therapeutic use for R. officinalis as an alternative for liver cirrhosis.

  9. Distinctive expression patterns of hypoxia-inducible factor-1α and endothelial nitric oxide synthase following hypergravity exposure

    Science.gov (United States)

    Yoon, Gun; Oh, Choong Sik; Kim, Hyun-Soo

    2016-01-01

    This study was designed to examine the expression of hypoxia-inducible factor-1α (HIF-1α) and the level and activity of endothelial nitric oxide synthase (eNOS) in the hearts and livers of mice exposed to hypergravity. Hypergravity-induced hypoxia and the subsequent post-exposure reoxygenation significantly increased cardiac HIF-1α levels. Furthermore, the levels and activity of cardiac eNOS also showed significant increase immediately following hypergravity exposure and during the reoxygenation period. In contrast, the expression of phosphorylated Akt (p-Akt) and phosphorylated extracellular signal-regulated kinase (p-ERK) showed significant elevation only during the reoxygenation period. These data raise the possibility that the increase in cardiac HIF-1α expression induced by reoxygenation involves a cascade of signaling events, including activation of the Akt and ERK pathways. In the liver, HIF-1α expression was significantly increased immediately after hypergravity exposure, indicating that hypergravity exposure to causes hepatocellular hypoxia. The hypergravity-exposed livers showed significantly higher eNOS immunoreactivity than did those of control mice. Consistent with these results, significant increases in eNOS activity and nitrate/nitrite levels were also observed. These findings suggest that hypergravity-induced hypoxia plays a significant role in the upregulation of hepatic eNOS. PMID:27191892

  10. Drug –induced liver injury:a review

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    Sreya Kosanam

    2015-03-01

    Full Text Available The incidence of drug induced liver injury (DILI is about 1/1000 to 1/10000 among patients who receive therapeutic drug doses. Drug induced hepatotoxicity is a major cause of acute and chronic liver disease. The severity of liver damage ranges from nonspecific changes in liver structure to acute liver failure, cirrhosis and liver cancer. Some common agents that can cause liver injury are acetaminophen, antibiotics, statins, INH and herbal drugs.Drug-induced hepatotoxicity can be categorized based on the pattern of liver enzyme alteration (hepatocellular, cholestatic or mixed pattern, the mechanism of hepatotoxicity (direct, immune mediated or idiosyncratic and histologic findings on liver biopsy (steatosis or sinusoidal obstruction syndrome. Treatment options for DILI include discontinuing the drug, conservative measurements and liver transplantation in the case of non-acetaminophen induced hepatotoxicity.

  11. Dissecting structural and electronic effects in inducible nitric oxide synthase.

    Science.gov (United States)

    Hannibal, Luciana; Page, Richard C; Haque, Mohammad Mahfuzul; Bolisetty, Karthik; Yu, Zhihao; Misra, Saurav; Stuehr, Dennis J

    2015-04-01

    Nitric oxide synthases (NOSs) are haem-thiolate enzymes that catalyse the conversion of L-arginine (L-Arg) into NO and citrulline. Inducible NOS (iNOS) is responsible for delivery of NO in response to stressors during inflammation. The catalytic performance of iNOS is proposed to rely mainly on the haem midpoint potential and the ability of the substrate L-Arg to provide a hydrogen bond for oxygen activation (O-O scission). We present a study of native iNOS compared with iNOS-mesohaem, and investigate the formation of a low-spin ferric haem-aquo or -hydroxo species (P) in iNOS mutant W188H substituted with mesohaem. iNOS-mesohaem and W188H-mesohaem were stable and dimeric, and presented substrate-binding affinities comparable to those of their native counterparts. Single turnover reactions catalysed by iNOSoxy with L-Arg (first reaction step) or N-hydroxy-L-arginine (second reaction step) showed that mesohaem substitution triggered higher rates of Fe(II)O₂ conversion and altered other key kinetic parameters. We elucidated the first crystal structure of a NOS substituted with mesohaem and found essentially identical features compared with the structure of iNOS carrying native haem. This facilitated the dissection of structural and electronic effects. Mesohaem substitution substantially reduced the build-up of species P in W188H iNOS during catalysis, thus increasing its proficiency towards NO synthesis. The marked structural similarities of iNOSoxy containing native haem or mesohaem indicate that the kinetic behaviour observed in mesohaem-substituted iNOS is most heavily influenced by electronic effects rather than structural alterations.

  12. Inducible nitric oxide synthase haplotype associated with migraine and aura.

    Science.gov (United States)

    de O S Mansur, Thiago; Gonçalves, Flavia M; Martins-Oliveira, Alisson; Speciali, Jose G; Dach, Fabiola; Lacchini, Riccardo; Tanus-Santos, Jose E

    2012-05-01

    Migraine is a complex neurological disorder with a clear neurogenic inflammatory component apparently including enhanced nitric oxide (NO) formation. Excessive NO amounts possibly contributing to migraine are derived from increased expression and activity of inducible NO synthase (iNOS). We tested the hypothesis that two functional, clinically relevant iNOS genetic polymorphisms (C(-1026)A-rs2779249 and G2087A-rs2297518) are associated with migraine with or without aura. We studied 142 healthy women without migraine (control group) and 200 women with migraine divided into two groups: 148 with migraine without aura (MWA) and 52 with aura (MA). Genotypes were determined by real-time polymerase chain reaction using the Taqman(®) allele discrimination assays. The PHASE 2.1 software was used to estimate the haplotypes. The A allele for the G2087A polymorphism was more commonly found in the MA group than in the MWA group (28 vs. 18%; P 0.05). The haplotype combining both A alleles for the two polymorphisms was more commonly found in the MA group than in the control group or in the MWA group (19 vs. 10 or 8%; P = 0.0245 or 0.0027, respectively). Our findings indicate that the G2087A and the C(-1026)A polymorphism in the iNOS gene affect the susceptibility to migraine with aura when their effects are combined within haplotypes, whereas the G2087A affects the susceptibility to aura in migraine patients. These finding may have therapeutic implications when examining the effects of selective iNOS inhibitors.

  13. Phenotypes and Pathology of Drug-Induced Liver Disease.

    Science.gov (United States)

    Goodman, Zachary D

    2017-02-01

    Drug hepatotoxicity can simulate nearly any clinical syndrome or pathologic lesion that may occur in the liver, so clinical and histopathologic diagnosis of drug-induced liver injury may be difficult. Nevertheless, most drugs that are known to idiosyncratic liver injury tend to cause patterns of injury that produce characteristic phenotypes. Recognition of these patterns or phenotypes in liver biopsy material is helpful in evaluation of clinical cases of suspected drug-induced liver injury.

  14. Expression of inducible nitric oxide synthase and nitric oxide production in the mud-dwelled air-breathing singhi catfish, Heteropneustes fossilis under condition of water shortage.

    Science.gov (United States)

    Choudhury, Mahua G; Saha, Nirmalendu

    2012-12-01

    Nitric oxide (NO) is known to be an important regulator molecule for regulating the multiple signaling pathways and also to play diverse physiological functions in mammals including that of adaptation to various stresses. The present study reports on the production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS) enzyme that produces NO from l-arginine in the freshwater air-breathing catfish (Heteropneustes fossilis) while dwelling inside the mud peat under semidry conditions. Desiccation stress, due to mud-dwelling for 2 weeks, led to significant increase of NO concentration in different tissues and in plasma of singhi catfish, and also the increase of NO efflux from the perfused liver with an accompanying increase of toxic ammonia level in different tissues. Mud-dwelling also resulted to induction of iNOS activity, expression of iNOS protein in different tissues after 7 days with further increase after 14 days, which otherwise was not detectable in control fish. Further, mud-dwelling also resulted to a significant expression of iNOS mRNA after 7 days with a more increase of mRNA level after 14 days, suggesting that the desiccation stress caused transcriptional regulation of iNOS gene. Immunocytochemical analysis indicated the zonal specific expression of iNOS protein in different tissues. Desiccation stress also led to activation and nuclear translocation of nuclear factor кB (NFкB) in hepatic cells. These results suggest that the activation of iNOS gene under desiccation-induced stresses such as high ammonia load was probably mediated through the activation of one of the major transcription factors, the NFкB. This is the first report of desiccation-induced induction of iNOS gene, iNOS protein expression leading to more generation of NO while living inside the mud peat under condition of water shortage in any air-breathing teleosts. 2012 Elsevier Inc. All rights reserved

  15. The protective effect of niacinamide on ischemia-reperfusion-induced liver injury.

    Science.gov (United States)

    Chen, C F; Wang, D; Hwang, C P; Liu, H W; Wei, J; Lee, R P; Chen, H I

    2001-01-01

    Reperfusion of ischemic liver results in the generation of oxygen radicals, nitric oxide (NO) and their reaction product peroxynitrite, all of which may cause strand breaks in DNA, which activate the nuclear enzyme poly(ADP ribose)synthase (PARS). This results in rapid depletion of intracellular nicotinamide adenine dinucleotide and adenosine 5'-triphosphate (ATP) and eventually induces irreversible cytotoxicity. In this study, we demonstrated that niacinamide, a PARS inhibitor, attenuated ischemia/reperfusion (I/R)-induced liver injury. Ischemia was induced by clamping the common hepatic artery and portal vein of rats for 40 min. Thereafter, flow was restored and the liver was reperfused for 90 min. Blood samples collected prior to I and after R were analyzed for methyl guanidine (MG), NO, tumor necrosis factor (TNF-alpha) and ATP. Blood levels of aspartate transferase (AST), alanine transferase (ALT) and lactate dehydrogenase (LDH) which served as indexes of liver injury were measured. This protocol resulted in elevation of the blood NO level (p niacinamide (10 mM), liver injury was significantly attenuated, while blood ATP content was reversed. In addition, MG, TNF-alpha and NO release was attenuated. These results indicate that niacinamide, presumably by acting with multiple functions, exerts potent anti-inflammatory effects in I/R-induced liver injury.

  16. Alcohol-induced steatosis in liver cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Alcohol-induced fatty liver (steatosis) was believed to result from excessive generation of reducing equivalents from ethanol metabolism, thereby enhancing fat accumulation. Recent findings have revealed a more complex picture in which ethanol oxidation is still required,but specific transcription as well as humoral factors also have important roles. Transcription factors involved include the sterol regulatory element binding protein 1 (SREBP-1)which is activated to induce genes that regulate lipid biosynthesis. Conversely, ethanol consumption causes a general down-regulation of lipid (fatty acid) oxidation, a reflection of inactivation of the peroxisome proliferatoractivated receptor-alpha (PPAR-α) that regulates genes involved in fatty acid oxidation. A third transcription factor is the early growth response-1 (Egr-1), which is strongly induced prior to the onset of steatosis. The activities of all these factors are governed by that of the principal regulatory enzyme, AMP kinase. Important humoral factors, including adiponectin, and tumor necrosis factor-α(TNF-α), also regulate alcohol-induced steatosis. Their levels are affected by alcohol consumption and by each other. This review will summarize the actions of these proteins in ethanol-elicited fatty liver. Because steatosis is now regarded as a significant risk factor for advanced liver pathology, an understanding of the molecular mechanisms in its etiology is essential for development of effective therapies.

  17. Changes of nitric oxide and endothelin, thromboxane A2 and prostaglandin in cirrhotic patients undergoing liver transplantation

    Institute of Scientific and Technical Information of China (English)

    Zi-Qing Hei; He-Qing Huang; Chen-Fang Luo; Shang-Rong Li; Gang-Jian Luo

    2006-01-01

    AIM: To investigate the perioperative changes of nitric oxide (NO) and endothelin (ET), thromboxane A2 (TXA2) and prostaglandin (PGI2) during liver transplantation in end-stage liver disease patients.METHODS: Twenty-seven patients with end-stage cirrhosis undergoing liver transplantation were enrolled in this prospective study. Blood samples were obtained from superior vena at five different surgical stages.Plasma concentrations of nitrate and nitrite were determined to reflect plasma NO levels. Plasma levels of ET-1,6-keto-PGF1 alpha and thromboxane B2 (TXB2),the latter two being stable metabolites of PGI2 and TXA2 respectively, were measured.RESULTS: The NO level decreased significantly after vascular cross-clamping and increased significantly at 30 min after reperfusion. While the ET levels at 30 min after clamping and after reperfusion were significantly elevated. The ratio of NO/ET decreased significantly at 30 min after vascular cross-clamping and at the end of surgery. The PGI2 level and the TXA2 during liver transplantation were significantly higher than the baseline level, but the ratio of TXA2/PGI2 decreased significantly at 30 min after clamping.CONCLUSION: NO/ET and TXA2/PGI2 change during liver transplantation. Although the precise mechanism remains unknown, they may play a role in the pathobiology of a variety of liver transplant-relevant processes.

  18. Tyrosol attenuates ischemia-reperfusion-induced kidney injury via inhibition of inducible nitric oxide synthase.

    Science.gov (United States)

    Wang, Pengqi; Zhu, Qingjun; Wu, Nan; Siow, Yaw L; Aukema, Harold; O, Karmin

    2013-04-17

    Tyrosol is a natural phenolic antioxidant compound. Oxidative stress represents one of the important mechanisms underlying ischemia-reperfusion-induced kidney injury. The aim of this study was to investigate the effect of tyrosol against ischemia-reperfusion-induced acute kidney injury. The left kidney of Sprague-Dawley rats was subjected to 45 min of ischemia followed by reperfusion for 6 h. Ischemia-reperfusion caused an increase in peroxynitrite formation and lipid peroxidation. The level of nitric oxide (NO) metabolites and the mRNA of inducible nitric oxide synthase (iNOS) were elevated in ischemia-reperfused kidneys. Administration of tyrosol (100 mg/kg body weight) to rats prior to the induction of ischemia significantly reduced peroxynitrite formation, lipid peroxidation, and the level of NO metabolites. Tyrosol administration also attenuated ischemia-reperfusion-induced NF-κB activation and iNOS expression. Such a treatment improved kidney function. Results suggest that tyrosol may have a protective effect against acute kidney injury through inhibition of iNOS-mediated oxidative stress.

  19. Influence of environmental ammonia on the production of nitric oxide and expression of inducible nitric oxide synthase in the freshwater air-breathing catfish (Heteropneustes fossilis)

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, Mahua G. [Biochemical Adaptation Laboratory, Department of Zoology, North-Eastern Hill University, Shillong 793022 (India); Saha, Nirmalendu, E-mail: nsaha@nehu.ac.in [Biochemical Adaptation Laboratory, Department of Zoology, North-Eastern Hill University, Shillong 793022 (India)

    2012-07-15

    Highlights: Black-Right-Pointing-Pointer High environmental ammonia caused more production and accumulation of NO in air-breathing catfish (Heteropneustes fossilis). Black-Right-Pointing-Pointer Hyper-ammonia stress caused induction and zonal specific expression of iNOS enzyme protein, mRNA expression in different tissues. Black-Right-Pointing-Pointer Activation of NF{kappa}B that resulted under hyper-ammonia stress was believed to be the cause of induction of iNOS gene. - Abstract: Nitric oxide (NO) is a highly versatile and unique ubiquitous signaling molecule, and is known to play diverse physiological functions in mammals including those of adaptation to various stresses. The present study reports on the influence of exposure to high external ammonia (HEA) on the production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS), that produces NO from L-arginine in the freshwater air-breathing catfish (Heteropneustes fossilis), which is reported to tolerate a very HEA. Some levels of NO were found to be present in all the tissues and also in plasma of control fish, which further enhanced significantly in fishes treated with high concentrations of environmental ammonia (25 and 50 mM ammonium chloride) for 7 days, accompanied by more efflux of NO from the perfused liver. This was accomplished by the induction of iNOS activity in different tissues of fish exposed to HEA, which otherwise was not detectable in control fish. Exposure to 25 mM ammonium chloride also led to a significant expression of iNOS protein in different tissues, followed by further increase at 50 mM ammonium chloride. Further, there was an increase in the expression of iNOS mRNA in ammonia-treated fish, thus suggesting that the expression of iNOS gene under hyper-ammonia stress was probably regulated at the transcriptional level. Immunocytochemical analysis indicated that the expression of iNOS in different tissues was zonal specific and not expressed uniformly

  20. Progesterone modulates the LPS-induced nitric oxide production by a progesterone-receptor independent mechanism.

    Science.gov (United States)

    Wolfson, Manuel Luis; Schander, Julieta Aylen; Bariani, María Victoria; Correa, Fernando; Franchi, Ana María

    2015-12-15

    Genital tract infections caused by Gram-negative bacteria induce miscarriage and are one of the most common complications of human pregnancy. LPS administration to 7-day pregnant mice induces embryo resorption after 24h, with nitric oxide playing a fundamental role in this process. We have previously shown that progesterone exerts protective effects on the embryo by modulating the inflammatory reaction triggered by LPS. Here we sought to investigate whether the in vivo administration of progesterone modulated the LPS-induced nitric oxide production from peripheral blood mononuclear cells from pregnant and non-pregnant mice. We found that progesterone downregulated LPS-induced nitric oxide production by a progesterone receptor-independent mechanism. Moreover, our results suggest a possible participation of glucocorticoid receptors in at least some of the anti-inflammatory effects of progesterone.

  1. Hemodynamic and antifibrotic effects of a selective liver nitric oxide donor V-PYRRO/NO in bile duct ligated rats

    Institute of Scientific and Technical Information of China (English)

    Frédéric Moal; Dominique Bonnefont-Rousselot; Marie Christine Rousselet; Paul Calès; Nary Veal; Eric Vuillemin; Eric Barrière; Jianhua Wang; Lionel Fizanne; Frédéric Oberti; Olivier Douay; Yves Gallois

    2006-01-01

    AIM: To assess whether a liver specific nitric oxide (NO)donor (V-PYRRO/NO) would prevent the development of portal hypertension and liver fibrosis in rats with bile duct ligation (BDL).METHODS: Treatment (placebo or V-PYRRO/NO0.53 μmol/kg per hour) was administered i.v. to rats 2 d before BDL (D-2) and maintained until the day of hemodynamic measurement (D26). Intra-hepatic NO level was estimated by measuring liver cGMP level. Effects of V-PYRRO/NO on liver fibrosis and lipid peroxidation were also assessed.RESULTS: Compared to placebo treatment, V-PYRRO/NO improved splanchnic hemodynamics in BDL rats:portal pressure was significantly reduced by 27% (P< 0.0001) and collateral circulation development was almost completely blocked (splenorenal shunt blood flow by 74%, P = 0.007). Moreover, V-PYRRO/NO significantly prevented liver fibrosis development in BDL rats (by 30% in hepatic hydroxyproline content and 31% in the area of fibrosis, P < 0.0001 respectively), this effect being probably due to a decrease in lipid peroxidation by 44% in the hepatic malondialdehyde level (P =0.007). Interestingly, we observed a significant and expected increase in liver cGMP, without any systemic hemodynamic effects (mean arterial pressure, vascular systemic resistance and cardiac output) in both shamoperated and BDL rats treated with V-PYRRO/NO. This result is in accordance with studies on V-PYRRO/NOmetabolism showing a specific release of NO in the liver.CONCLUSION: Continuous administrations of V-PYRRO/NO in BDL rats improved liver fibrosis and splanchnic hemodynamics without any noxious systemic hemodynamic effects.

  2. Human Ex-Vivo Liver Model for Acetaminophen-induced Liver Damage

    Science.gov (United States)

    Schreiter, Thomas; Sowa, Jan-Peter; Schlattjan, Martin; Treckmann, Jürgen; Paul, Andreas; Strucksberg, Karl-Heinz; Baba, Hideo A.; Odenthal, Margarete; Gieseler, Robert K.; Gerken, Guido; Arteel, Gavin E.; Canbay, Ali

    2016-01-01

    Reliable test systems to identify hepatotoxicity are essential to predict unexpected drug-related liver injury. Here we present a human ex-vivo liver model to investigate acetaminophen-induced liver injury. Human liver tissue was perfused over a 30 hour period with hourly sampling from the perfusate for measurement of general metabolism and clinical parameters. Liver function was assessed by clearance of indocyanine green (ICG) at 4, 20 and 28 hours. Six pieces of untreated human liver specimen maintained stable liver function over the entire perfusion period. Three liver sections incubated with low-dose acetaminophen revealed strong damage, with ICG half-lives significantly higher than in non-treated livers. In addition, the release of microRNA-122 was significantly higher in acetaminophen-treated than in non-treated livers. Thus, this model allows for investigation of hepatotoxicity in human liver tissue upon applying drug concentrations relevant in patients. PMID:27550092

  3. Relationship between inducible nitric oxide synthase expression and angiogenesis in primary gallbladder carcinoma tissue

    Institute of Scientific and Technical Information of China (English)

    Xin-Jie Niu; Zuo-Ren Wang; Sheng-Li Wu; Zhi-Min Geng; Yun-Feng Zhang; Xing-Lei Qing

    2004-01-01

    AIM: To explore the relationship between angiogenesis and biological behaviors of primary gallbladder carcinoma (PGBC),the relationship between the expression of inducible nitric oxide synthase (iNOS) and biological behaviors of PGBC and its relationship with the expression of iNOS and angiogenesis of PGBC.METHODS: The expression of iNOS and micro-vessel density (MVD) were assessed by immunohistochemical method and image analysis system in 40 specimens of PGBC and in 8 specimens of normal gallbladder. The immunostaining results and related clinicopathologic materials were analyzed by statistical methods.RESULTS: MVD in PGBC was significantly higher than that in normal gallbladder tissue (46±14 vS 14±6, P<0.05), and was not related with age, gender, tumor size and histological type. MVD of poorly and undifferentiated tumor tissues was higher than that of moderately-differentiated and welldifferentiated tumor tissues (52±9 vs43±9 vs33±6, P<0.01).MVD of Nevin IV and V stages was higher than that of Nevin I, II and III stages (52±8 Vs37±13, P<0.01). MVD of cases with lymphatic or liver metastasis was significantly higher than that without liver metastasis (55±6 vS42±10, P<0.05)or lymphatic metastasis (53±8 vs38±8, P<0.01). The positive level index (PLI) of iNOS in PGBC was 0.435±0.134, and was not related with age, gender, tumor size, histological type,differentiation and clinical stage of PGBC. The PLI of iNOS in cases with lymphatic metastasis was higher than that without lymphatic metastasis (0.573±0.078 vs0.367±0.064,P<0.01). The PLI of iNOS in cases with liver metastasis was higher than that without liver metastasis (0.533±0.067 vS 0.424±0.084, P<0.05). There was a significant correlation between PLI of iNOS and MVD in PGBC (P<0.05).CONCLUSION: Angiogenesis of PGBC is significantly related to the biological behaviors of PGBC. The expression of iNOS is related to the biological behaviors of PGBC. The detection of MVD and the

  4. Autophagy and ethanol-induced liver injury

    Institute of Scientific and Technical Information of China (English)

    Terrence M Donohue Jr

    2009-01-01

    The majority of ethanol metabolism occurs in the liver. Consequently, this organ sustains the greatest damage from ethanol abuse. Ethanol consumption disturbs the delicate balance of protein homeostasis in the liver, causing intracellular protein accumulation due to a disruption of hepatic protein catabolism.Evidence indicates that ethanol or its metabolism impairs trafficking events in the liver, including the process of macroautophagy, which is the engulfment and degradation of cytoplasmic constituents by the lysosomal system. Autophagy is an essential, ongoing cellular process that is highly regulated by nutrients,endocrine factors and signaling pathways. A great number of the genes and gene products that govern the autophagic response have been characterized and the major metabolic and signaling pathways that activate or suppress autophagy have been identified. This review describes the process of autophagy, its regulation and the possible mechanisms by which ethanol disrupts the process of autophagic degradation. The implications of autophagic suppression are discussed in relation to the pathogenesis of alcohol-induced liver injury.

  5. Imatinib-induced fatal acute liver failure

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Imatinib mesylate is a drug that has been approved for treatment of chronic myeloid leukemia (CML) in blast crisis, accelerated or chronic phase, and also for advanced gastrointestinal stromal tumors. Severe hepatic toxicity and three deaths from hepatic failure have been reported. We report the case of a 51-year-old woman who was admitted to our institution with severe acute hepatitis. She was diagnosed with CML and began treatment with imatinib mesylate at a dose of 400 mg/d.Five months after beginning treatment, she developed severe hepatitis associated with coagulopathy, and was admitted to our institution. She had been consuming acetaminophen 500-1000 mg/d after the onset of symptoms. She had a progressive increase in bilirubin level and a marked decrease of clotting factor Ⅴ. Five days after admission, grade Ⅱ encephalopathy developed and she was referred for liver transplantation. Her clinical condition progressively deteriorated, and 48 h after being referred for transplantation she suffered a cardiac arrest and died. This report adds concern about the possibility of imatinib-mesylate-induced hepatotoxicity and liver failure, particularly in the case of concomitant use with acetaminophen. Liver function tests should be carefully monitored during treatment and, with the appearance of any elevation of liver function tests, treatment should be discontinued.

  6. Significance of nitric oxide on the pathogenesis of steroid-induced femoral head necrosis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Steroid-induced femoral head necrosis is claimed to be an ischemic femoral head disease. But there is no discussion on the role of nitric oxide (NO) in the idiopathic disease. The concentration of NO indirectly in serum with steroid induced avascular necrosis of femoral head (ANFH) and in controls are studied in this article.

  7. Pressure-related activation of inducible nitric oxide synthase

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A lot of reports suggested that inducible nitric oxide synthase (iNOS) has a very different nature from constitutive NOS including endothelial NOS (eNOS) and neural NOS (nNOS). When exposed to cytokines or bacterial products, iNOS could be greatly activated and produces hundreds or thousands fold more NO than it does usually. Whether iNOS activation is arterial pressure related is not clear. In the present experiment, we studied three groups(n=6) of Sprague Dawley (SD) rats with implanted aorta and venous catheters that were maintained on 1 mEq/d, 12.5 mEq/d and 25 mEq/d of sodium intake respectively. Pulsatile arterial pressure signals from the amplifier were sent to a digital computer and the urine samples were taken every other day for nitrate/nitrite excretion (UNOx) assay using Greiss Reaction. After 6 days infusion, the rats were euthanized with an overdose of sodium pentobarbital, and the renal medullas were rapidly removed and frozen on dry ice for iNOS activity assay. Morever separate groups of hypertensive rats including spontaneously hypertensive rat (SHR, n=6) and High NaCl-induced hypertensive rat (NaHR, n=6) were used to measure renal iNOS protein by Western Blotting. The results showed that the mean arterial pressure (MAP) were significantly increased with the increase intake of sodium, the MAP (mmHg) at day 6 were 99.6±3.5,116.65±4.2 and 125.43±4.5, and the iNOS activity (nmol*g-1 protein*min-1) were 122.3±23.4, 342.4±35.6 and 623.9±65.4 in 1 mEq/d, 12.5 mEq/d and 25 mEq/d of sodium intake-rats respectively. At the same time, UNOx at day 6 were also increased, in turn, to 5 865.6±343.0 (for 12.5 mEq/d intake-rats) and (9 642.8±1 045.3) (for 25 mEq/d sodium intake-rats) nmol/d from (3 834.9±234.8) nmol/d of 1 mEq/d sodium intake-rats respectively. Western blotting showed that the renal medullary iNOS protein in SHR and NaHR were increased by 178%±13% and 104%±9% of normal Wistar rats. The data indicates that elevated arterial pressure

  8. Translational biomarkers of acetaminophen-induced acute liver injury.

    Science.gov (United States)

    Beger, Richard D; Bhattacharyya, Sudeepa; Yang, Xi; Gill, Pritmohinder S; Schnackenberg, Laura K; Sun, Jinchun; James, Laura P

    2015-09-01

    Acetaminophen (APAP) is a commonly used analgesic drug that can cause liver injury, liver necrosis and liver failure. APAP-induced liver injury is associated with glutathione depletion, the formation of APAP protein adducts, the generation of reactive oxygen and nitrogen species and mitochondrial injury. The systems biology omics technologies (transcriptomics, proteomics and metabolomics) have been used to discover potential translational biomarkers of liver injury. The following review provides a summary of the systems biology discovery process, analytical validation of biomarkers and translation of omics biomarkers from the nonclinical to clinical setting in APAP-induced liver injury.

  9. Dimethylarginine Dimethylaminohydrolase/Nitric Oxide Synthase Pathway in Liver and Kidney: Protective Effect of Cyanidin 3-O-β-D-Glucoside on Ochratoxin-A Toxicity

    Directory of Open Access Journals (Sweden)

    Rosaria Acquaviva

    2012-05-01

    Full Text Available The aim of the present study was to evaluate the effect of long-term cyanidin 3-O-β-D-glucoside (C3G and/or Ochratoxin A (OTA-exposure on dimethylarginine dimethylamino hydrolase/nitric oxide synthase (DDAH/NOS pathway in rats. The experiments were performed in rats supplemented with C3G (1 g/kg feed, OTA (200 ppb, and OTA + C3G. After 4 weeks of daily treatment, liver and kidneys were processed for eNOS, iNOS and DDAH-1 Western blotting, nitrite levels evaluation and DDAH activity determination. Results show that OTA is able to induce iNOS both in kidney and liver, whereas OTA is able to induce eNOS and DDAH-1 overexpression and DDAH activation only in kidney, resulting in increased nitrite levels. In kidney of OTA + C3G fed rats, iNOS, eNOS and DDAH-1 expression were less pronounced compared with those observed in the OTA-treated group. Coherent with the decreased iNOS, eNOS and DDAH-1 expression a decrease in nitrite levels and DDAH activity was observed in the OTA + C3G group. Results demonstrate that C3G is able to counteract the deleterious effects of chronic consumption of OTA and also suggest a possible involvement of iNOS-eNOS-DDAH impairment in OTA nephrocarcinogenity.

  10. Diallyl sulfide protects against N-nitrosodiethylamine-induced liver tumorigenesis: Role of aldose reductase

    Institute of Scientific and Technical Information of China (English)

    Safinaz S Ibrahim; Noha N Nassar

    2008-01-01

    AIM: To evaluate the protective effect of diallyl sulfide (DAS) against N-nitrosodiethylamine (NDEA)-induced liver carcinogenesis. METHODS: Male Wistar rats received either NDEA or NDEA together with DAS as protection. Liver energy metabolism was assessed in terms of lactate, pyruvate, lactate/pyruvate, ATP levels, lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G6PD) activities. In addition, membrane disintegration of the liver cells was evaluated by measuring lipid-peroxidation products, measured as malondialdehyde (MDA); nitric oxide (NO) levels; glucose-6-phosphatase (G6Pase), catalase (CAT) and superoxide dismutase (SOD) activities. Uver DNA level, glutathione-S-transferase (GST) and cytochrome c oxidase activities were used as DNA fragmentation indices. Aldose reductase (AR) activity was measured as an index for cancer cells resistant to chemotherapy and histopathological examination was performed on liver sections from different groups. RESULTS: NDEA significantly disturbed liver functions and most of the aforementioned indices. Treatment with DAS significantly restored liver functions and hepatocellular integrity; improved parameters of energy metabolism and suppressed free-radical generation. CONCLUSION: We provide evidence that DAS exerts a protective role on liver functions and tissue integrity in face of enhanced tumorigenesis caused by NDEA, as well as improving cancer-cell sensitivity to chemotherapy. This is mediated through combating oxidative stress of free radicals, improving the energy metabolic state of the cell, and enhancing the activity of G6Pase, GST and AR enzymes.

  11. Inducible nitric oxide synthase and guinea-pig ileitis induced by adjuvant

    Directory of Open Access Journals (Sweden)

    N. D. Seago

    1995-01-01

    Full Text Available We sought to establish a model of inflammatory bowel disease by augmenting the activity of the local immune system with Freund's complete adjuvant, and to determine if inducible nitric oxide synthase (iNOS expression and peroxynitrite formation accompanied the inflammatory condition. In anaesthetized guinea-pigs, a loop of distal ileum received intraluminal 50% ethanol followed by Freund's complete adjuvant. Control animals were sham operated. When the animals were killed 7 or 14 days later, loop lavage fluid was examined for nitrite and PGE2 levels; mucosal levels of granulocyte and macrophages were estimated by myeloperoxidase (MPO and N-acetyl-D-glucosaminidase (NAG activity, respectively. Cellular localization if iNOS and peroxynitrite formation were determined by immunohistochemistry with polyclonal antibodies directed against peptide epitopes of mouse iNOS and nitrotyrosine, respectfully. Adjuvant administration resulted in a persistent ileitis, featuring gut thickening, crypt hyperplasia, villus tip swelling and disruption, and cellular infiltration. Lavage levels of PGE2 and nitrite were markedly elevated by adjuvant treatment. Immunoreactive iNOS and nitrotyrosine bordered on detectability in normal animals but were markedly evident with adjuvant treatment at day 7 and particularly day 14. Immunohistochemistry suggested that enteric neurons and epithelia were major sites of iNOS activity and peroxynitrite formation. We conclude that local administration of adjuvant establishes a chronic ileitis. Inducible nitric oxide synthase may contribute to the inflammatory process.

  12. Acute alcohol-induced liver injury

    Directory of Open Access Journals (Sweden)

    Gavin Edward Arteel

    2012-06-01

    Full Text Available Alcohol consumption is customary in most cultures and alcohol abuse is common worldwide. For example, more than 50% of Americans consume alcohol, with an estimated 23.1% of Americans participating in heavy and/or binge drinking at least once a month. A safe and effective therapy for alcoholic liver disease (ALD in humans is still elusive, despite significant advances in our understanding of how the disease is initiated and progresses. It is now clear that acute alcohol binges not only can be acutely toxic to the liver, but also can contribute to the chronicity of ALD. Potential mechanisms by which acute alcohol causes damage include steatosis, dysregulated immunity and inflammation and altered gut permeability. Recent interest in modeling acute alcohol exposure has yielded new insights into potential mechanisms of acute injury, that also may well be relevant for chronic ALD. Recent work by this group on the role of PAI-1 and fibrin metabolism in mediating acute alcohol-induced liver damage serve as an example of possible new targets that may be useful for alcohol abuse, be it acute or chronic.

  13. Use of aminoguanidine, a selective inducible nitric oxide synthase inhibitor, to evaluate the role of nitric oxide in periapical inflammation.

    Science.gov (United States)

    Farhad, Ali R; Razavi, Seyedmohammad; Jahadi, Sanaz; Saatchi, Masoud

    2011-06-01

    The purpose of this study was to evaluate the effects of aminoguanidine (AG) as a selective inhibitor of inducible nitric oxide synthase (iNOS) on the degree of inflammatory response in periapical lesions in the canine teeth of cats. Root canals from 52 cat canine teeth were exposed to the oral cavity and sealed after 7 days. One day before pulp exposure, cats were administered either AG (experimental group) or normal saline (control group), which was continued on a daily basis until the day of sacrifice. Animals were sacrificed at 28 days after pulp exposure. Inflammatory response in the periapical zones was analyzed histologically. The degree of periapical inflammation in the AG group was significantly lower than that in the control group (P < 0.05). Selective iNOS inhibitors such as AG thus reduce the intensity of inflammatory responses in periapical lesions.

  14. Production of reactive oxygen species and expression of inducible nitric oxide synthase in rat isolated Kupffer cells stimulated by Leptospira interrogans and Borrelia burgdorferi

    Institute of Scientific and Technical Information of China (English)

    Antonella Marangoni; Silvia Accardo; Rita Aldini; Massimo Guardigli; Francesca Cavrini; Vittorio Sambri; Marco Montagnani; Aldo Roda; Roberto Cevenini

    2006-01-01

    AIM: To evaluate the production of reactive oxygen species (ROS) and the expression of indudble nitric oxide synthase (iNOS) in rat isolated Kupffer cells (KCs) stimulated by Leptospira interrogans and Borrelia burgdorferi.METHODS: Rat Kupffer cells were separated by perfusion of the liver with 0.05% collagenase, and purified by Percoll gradients. Purified Kupffer cells were tested in vitro with alive L.interogans and B. burgdorferi preparations. The production of ROS was determined by chemiluminescence, whereas iNOS protein expression was evaluated by Western blot assay using anti-iNOS antibodies.RESULTS: B. burgdorferi and to a less extent L. interrogans induced ROS production with a peak 35 min after infection. The chemiluminescence signal progressively diminished and was undetectable by 180 min of incubation. Leptospirae and borreliae induced an increased iNOS expression in Kupffer cells that peaked at 6 hours and was still evident 22 h after infection.CONCLUSION: Both genera of spirochetes induced ROS and iNOS production in rat Kupffer cells. Since the cause of liver damage both in leptospiral as well as in borrelial infections are still unknown, we suggest that leptospira and borrelia damage of the liver can be initially mediated by oxygen radicals, and is then maintained at least in part by nitric oxide.

  15. Formation of nitric oxide in an industrial burner measured by 2-D laser induced fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, A.; Bombach, R.; Kaeppeli, B. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    We have performed two-dimensional Laser Induced Fluorescence (2-D LIF) measurements of nitric oxide and hydroxyl radical distributions in an industrial burner at atmospheric pressure. The relative 2-D LIF data of NO were set to an absolute scale by calibration with probe sampling combined with gas analysis. (author) 3 figs., 7 refs.

  16. Pathophysiology of chronic nitric oxide synthase inhibition-induced fetal growth restriction in the rat

    NARCIS (Netherlands)

    Neerhof, M.G.; Synowiec, S.; Khan, S.; Thaete, L.G.

    2011-01-01

    Objective. To evaluate the pathophysiology of chronic nitric oxide synthase (NOS) inhibition-induced fetal growth restriction (FGR) in the rat. Methods. Timed-pregnant rats received L-NAME (2.5 mg/kg/h) with or without endothelin (ET-1) receptor A (ETA) antagonist from day 14 to 21 of gestation. In

  17. Constitutive expression of inducible nitric oxide synthase in the normal human colonic epithelium

    DEFF Research Database (Denmark)

    Perner, A; Andresen, L; Normark, M

    2002-01-01

    Inducible nitric oxide synthase (iNOS) in the human colon is considered expressed only in inflammatory states such as ulcerative or collagenous colitis. As subtle iNOS labelling was previously observed in some colonic mucosal biopsies from a heterogeneous group of controls with non-inflamed bowel...

  18. Astrocytes and microglia express inducible nitric oxide synthase in mice with experimental allergic encephalomyelitis

    DEFF Research Database (Denmark)

    Tran, E H; Hardin-Pouzet, H; Verge, G;

    1997-01-01

    Nitric oxide (NO), produced by inducible NO synthase (iNOS), may play a role in inflammatory demyelinating diseases of the central nervous system (CNS). We show upregulation of iNOS mRNA in CNS of SJL/J mice with experimental allergic encephalomyelitis (EAE). Using antibodies against mouse iNOS, ...

  19. Quantitative laser-induced fluorescence measurements of nitric oxide in a heavy-duty Diesel engine

    NARCIS (Netherlands)

    Verbiezen, K.; Klein-Douwel, R. J. H.; van Viet, A. P.; Donkerbroek, A. J.; Meerts, W. L.; Dam, N. J.; ter Meulen, J. J.

    2007-01-01

    We present quantitative, in-cylinder, UV-laser-induced fluorescence measurements of nitric oxide in a heavy-duty Diesel engine. Processing of the raw fluorescence signals includes a detailed correction, based on additional measurements, for the effect of laser beam and fluorescence attenuation, and

  20. Constitutive expression of inducible nitric oxide synthase in the normal human colonic epithelium

    DEFF Research Database (Denmark)

    Perner, A; Andresen, Lars; Normark, M;

    2002-01-01

    Inducible nitric oxide synthase (iNOS) in the human colon is considered expressed only in inflammatory states such as ulcerative or collagenous colitis. As subtle iNOS labelling was previously observed in some colonic mucosal biopsies from a heterogeneous group of controls with non-inflamed bowel...

  1. Regulation of Injury-Induced Neurogenesis by Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Bruno P. Carreira

    2012-01-01

    Full Text Available The finding that neural stem cells (NSCs are able to divide, migrate, and differentiate into several cellular types in the adult brain raised a new hope for restorative neurology. Nitric oxide (NO, a pleiotropic signaling molecule in the central nervous system (CNS, has been described to be able to modulate neurogenesis, acting as a pro- or antineurogenic agent. Some authors suggest that NO is a physiological inhibitor of neurogenesis, while others described NO to favor neurogenesis, particularly under inflammatory conditions. Thus, targeting the NO system may be a powerful strategy to control the formation of new neurons. However, the exact mechanisms by which NO regulates neural proliferation and differentiation are not yet completely clarified. In this paper we will discuss the potential interest of the modulation of the NO system for the treatment of neurodegenerative diseases or other pathological conditions that may affect the CNS.

  2. Nitric oxide and redox regulation in the liver: Part I. General considerations and redox biology in hepatitis.

    Science.gov (United States)

    Diesen, Diana L; Kuo, Paul C

    2010-07-01

    Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are created in normal hepatocytes and are critical for normal physiologic processes, including oxidative respiration, growth, regeneration, apoptosis, and microsomal defense. When the levels of oxidation products exceed the capacity of normal antioxidant systems, oxidative stress occurs. This type of stress, in the form of ROS and RNS, can be damaging to all liver cells, including hepatocytes, Kupffer cells, stellate cells, and endothelial cells, through induction of inflammation, ischemia, fibrosis, necrosis, apoptosis, or through malignant transformation by damaging lipids, proteins, and/or DNA. In Part I of this review, we will discuss basic redox biology in the liver, including a review of ROS, RNS, and antioxidants, with a focus on nitric oxide as a common source of RNS. We will then review the evidence for oxidative stress as a mechanism of liver injury in hepatitis (alcoholic, viral, nonalcoholic). In Part II of this review, we will review oxidative stress in common pathophysiologic conditions, including ischemia/reperfusion injury, fibrosis, hepatocellular carcinoma, iron overload, Wilson's disease, sepsis, and acetaminophen overdose. Finally, biomarkers, proteomic, and antioxidant therapies will be discussed as areas for future therapeutic interventions.

  3. Nitric oxide and redox regulation in the liver: part II. Redox biology in pathologic hepatocytes and implications for intervention.

    Science.gov (United States)

    Diesen, Diana L; Kuo, Paul C

    2011-05-01

    Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are created in normal hepatocytes and are critical for normal physiologic processes, including oxidative respiration, growth, regeneration, apoptosis, and microsomal defense. When the levels of oxidation products exceed the capacity of normal antioxidant systems, oxidative stress occurs. This type of stress, in the form of ROS and RNS, can be damaging to all liver cells, including hepatocytes, Kupffer cells, stellate cells, and endothelial cells, through induction of inflammation, ischemia, fibrosis, necrosis, apoptosis, or through malignant transformation by damaging lipids, proteins, and/or DNA. In Part I of this review, we will discuss basic redox biology in the liver, including a review of ROS, RNS, and antioxidants, with a focus on nitric oxide as a common source of RNS. We will then review the evidence for oxidative stress as a mechanism of liver injury in hepatitis (alcoholic, viral, nonalcoholic). In Part II of this review, we will review oxidative stress in common pathophysiologic conditions, including ischemia/reperfusion injury, fibrosis, hepatocellular carcinoma, iron overload, Wilson's disease, sepsis, and acetaminophen overdose. Finally, biomarkers, proteomic, and antioxidant therapies will be discussed as areas for future therapeutic interventions.

  4. The innervation of rainbow trout (Oncorhynchus mykiss) liver: protein gene product 9.5 and neuronal nitric oxide synthase immunoreactivities.

    Science.gov (United States)

    Esteban, F J; Jiménez, A; Barroso, J B; Pedrosa, J A; del Moral, M L; Rodrigo, J; Peinado, M A

    1998-08-01

    We have explored the innervation of the rainbow trout (O. mykiss) liver using immunohistochemical procedures and light microscopy to detect in situ protein gene product 9.5 and neuronal nitric oxide synthase immunoreactivities (PGP-IR and NOS-IR). The results showed PGP-IR nerve fibres running with the extralobular biliary duct (EBD), hepatic artery (EHA) and portal vein (EPV) that form the hepatic hilum, as well as following the spatial distribution of the intrahepatic blood vessel and biliary channels. These nerve fibres appear as single varicose processes, thin bundles, or thick bundles depending on their diameter and location in the wall of the blood vessel or biliary duct. No PGP-IR fibres were detected in the liver parenchyma. NOS-IR nerve fibres were located only in the vessels and ducts that form the hepatic hilum (EBD, EHA, EPV); in addition, NOS-IR nerve cell bodies were found isolated or forming ganglionated plexuses in the peribiliary fibromuscular tissue of the EBD. No PGP-IR ganglionated plexuses were detected in the EBD. The location of the general (PGP-IR) and nitrergic (nNOS-IR) intrinsic nerves of the trout liver suggest a conserved evolutionary role of the nervous control of hepatic blood flow and hepatobiliary activity.

  5. Chlorogenic and caftaric acids in liver toxicity and oxidative stress induced by methamphetamine.

    Science.gov (United States)

    Koriem, Khaled M M; Soliman, Rowan E

    2014-01-01

    Methamphetamine intoxication can cause acute hepatic failure. Chlorogenic and caftaric acids are the major dietary polyphenols present in various foods. The aim of this study was to evaluate the protective role of chlorogenic and caftaric acids in liver toxicity and oxidative stress induced by methamphetamine in rats. Thirty-two male albino rats were divided into 4 equal groups. Group 1, which was control group, was injected (i.p) with saline (1 mL/kg) twice a day over seven-day period. Groups 2, 3, and 4 were injected (i.p) with methamphetamine (10 mg/kg) twice a day over seven-day period, where groups 3 and 4 were injected (i.p) with 60 mg/kg chlorogenic acid and 40 mg/kg caftaric acid, respectively, one day before methamphetamine injections. Methamphetamine increased serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, bilirubin, cholesterol, low-density lipoprotein, and triglycerides. Also, malondialdehyde in serum, liver, and brain and plasma and liver nitric oxide levels were increased while methamphetamine induced a significant decrease in serum total protein, albumin, globulin, albumin/globulin ratio, brain serotonin, norepinephrine and dopamine, blood and liver superoxide dismutase, and glutathione peroxidase levels. Chlorogenic and caftaric acids prior to methamphetamine injections restored all the above parameters to normal values. In conclusion, chlorogenic and caftaric acids before methamphetamine injections prevented liver toxicity and oxidative stress where chlorogenic acid was more effective.

  6. Supplementation with l-arginine stabilizes plasma arginine and nitric oxide metabolites, suppresses elevated liver enzymes and peroxidation in sickle cell anaemia.

    Science.gov (United States)

    Jaja, S I; Ogungbemi, S O; Kehinde, M O; Anigbogu, C N

    2016-06-01

    The effect of l-arginine on liver function in SCD has received little or no attention. The effect of a chronic, oral, low-dose supplementation with l-arginine (1gm/day for 6 weeks) on some liver enzymes, lipid peroxidation and nitric oxide metabolites was studied in 20 normal (non-sickle cell anaemia; NSCA) subjects and 20 sickle cell anaemia (SCA) subjects. Ten milliliters of blood was withdrawn from an ante-cubital vein for the estimation of plasma arginine concentration ([R]), alanine aminotransaminase (ALT), aspartate aminotransaminase (AST) and alkaline phosphatase (ALP), plasma total bilirubin concentration [TB], malondialdehyde concentration [MDA] and nitric oxide metabolites concentration [NOx]. Before supplementation, ALT, AST, ALP (pconcentration and nitric oxide metabolites levels in NSCA and SCA subjects. Responses in SCA subjects to l-arginine were more sensitive than in NSCA subjects.

  7. Role of nitric oxide and inducible nitric oxide synthase in human abdominal aortic aneurysms: a preliminary study

    Institute of Scientific and Technical Information of China (English)

    LIAO Ming-fang; LI Xiao-yan; JING Zai-ping; BAO Jun-min; ZHAO Zhi-qing; MEI Zhi-jun; LU Qing-shen; Feng Xiang; FENG Rui; ZHANG Su-zen

    2006-01-01

    Background Nitric oxide (NO) is an important mediator in the pathophysiology of many vascular diseases. However, the definite role of NO in human abdominal aortic aneurysm (AAA) formation is unclear. The aim of this study was to investigate production of NO and expression of inducible nitric oxide synthase (iNOS), and their possible role in AAA.Methods A total of 28 patients with AAA, 10 healthy controls, and 8 patients with arterial occlusive disease were enrolled into this study. Standard colorimetric assay was used to examine NO concentration in plasma from patients with AAA and normal controls, and in cultured smooth muscle cells (SMCs). Expression of iNOS in aortas and cultured SMCs were detected by immunochemistry. The correlation of iNOS expression with age of the patient, size of aneurysm, and degree of inflammation was also investigated by Cochran-Mantel-Haenszelχ2 test and Kendall' Tau correlation.Results Expression of iNOS increased significantly in the wall of aneurism in the patients with AAA compared to the healthy controls (P<0.05) and the patients with occlusive arteries (P<0.05). iNOS protein and media NOx (nitrite+nitrate) also increased in cultured SMCs from human AAA (n=4, P<0.05), while plasma NOx decreased in patients with AAA (n=25) compared to the healthy controls (n=20). There was a positive correlation between iNOS protein and degree of inflammation in aneurismal wall (Kendall coefficient=0.5032, P=0.0029)Conclusions SMCs and inflammatory cells were main cellular sources of increased iNOS in AAA, and NO may play a part in pathogenesis in AAA through inflammation.

  8. Azospirillum lectin – induced changes in the content of nitric oxide in wheat seedling roots

    Directory of Open Access Journals (Sweden)

    Alen’kina S.A.

    2010-11-01

    Full Text Available The lectin of Azospirillum brasilense Sp7 at 40 μg ml-1 elicited two peaks of induction of nitric oxide synthesis in the roots of wheat seedlings after 3 and 26 h of coincubation. The lectin of A. brasilense Sp7.2.3, a mutant defective in lectin activity, produced the same effect, but the activation of nitric oxide synthesis in the roots was less in the case of 26-h incubation. Exposure to the lectins for 3 h increased citrulline synthesis in the plant cell to the same extent. This finding indicated that the Azospirillum lectins activate nitric oxide production through the NO signal system of plants, thereby acting as inducers of adaptation processes in the roots of wheat seedlings.

  9. Resveratrol Induces Hepatic Mitochondrial Biogenesis Through the Sequential Activation of Nitric Oxide and Carbon Monoxide Production

    OpenAIRE

    Kim, Seul-Ki; Joe, Yeonsoo; Min ZHENG; Kim, Hyo Jeong; Yu, Jae-Kyoung; Cho, Gyeong Jae; Chang, Ki Churl; Kim, Hyoung Kyu; Han, Jin; Ryter, Stefan W.; Chung, Hun Taeg

    2014-01-01

    Aims: Nitric oxide (NO) can induce mitochondrial biogenesis in cultured cells, through increased guanosine 3′,5′-monophosphate (cGMP), and activation of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α). We sought to determine the role of NO, heme oxygenase-1 (HO-1), and its reaction product (carbon monoxide [CO]) in the induction of mitochondrial biogenesis by the natural antioxidant resveratrol. Results: S-nitroso-N-acetylpenicillamine (SNAP), an NO donor, induced ...

  10. Effects of intrathecal administration of nitric oxide synthase inhibitors on carrageenan-induced thermal hyperalgesia

    OpenAIRE

    Osborne, Michael G; Coderre, Terence J

    1999-01-01

    We examined the effects of various nitric oxide synthase (NOS) inhibitors on carrageenan-induced thermal hyperalgesia.First, we determined the time point at which a subcutaneous plantar injection of carrageenan into the rat hindpaw produced maximum thermal hyperalgesia. Subsequently, we demonstrated that intrathecal administration of the non-selective NOS inhibitor L-NG-nitro-arginine methyl ester (L-NAME) produces a dose-dependent reduction of carrageenan-induced thermal hyperalgesia.Four re...

  11. The nitric oxide donor S-nitrosoglutathione reduces apoptotic primary liver cell loss in a three-dimensional perfusion bioreactor culture model developed for liver support.

    Science.gov (United States)

    Prince, Jose M; Vodovotz, Yoram; Baun, Matthew J; Monga, Satdarshan Pal; Billiar, Timothy R; Gerlach, Jörg C

    2010-03-01

    Artificial extracorporeal support for hepatic failure has met with limited clinical success. In hepatocytes, nitric oxide (NO) functions as an antiapoptotic modulator in response to a variety of stresses. We hypothesized that NO administration would yield improved viability and hepatocellular restructuring in a four-compartment, hollow fiber-based bioreactor with integral oxygenation for dynamic three-dimensional perfusion of hepatic cells in bioartificial liver support systems. Isolated adult rat liver cells were placed in culture medium alone (control) or medium supplemented with various concentrations of an NO donor (S-nitrosoglutathione [GSNO]) in the bioreactors. Media samples were obtained from the cell perfusion circuit to monitor cellular response. After 24 and 72 h, histology biopsies were taken to investigate spontaneous restructuring of the cells. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to quantify apoptotic nuclei. Control bioreactors exhibited 47.9 +/- 2.9% (mean +/- standard error of the mean) apoptotic nuclei. In contrast, NO-treated bioreactors exhibited a biphasic response. Fewer apoptotic nuclei were seen in the 200 and 500 microM GSNO groups (14.4 +/- 0.4%). No effect was observed in the 10 microM GSNO group (47.3%), and increased TUNEL staining was observed in the 1000 microM GSNO group (82.6%). Media lactate dehydrogenase levels were lower in bioreactor groups treated with 200 or 500 microM GSNO (310 +/- 38 IU/L) compared with the control group (919 +/- 188 IU/L; p bioreactors at 24 h vs. 110 +/- 13 in controls; p = 0.851). Histologically, all of the bioreactor groups exhibited liver cell aggregates with some attached to the bioreactor capillaries. Increased numbers of cells in the aggregates and superior spontaneous restructuring of the cells were seen at 24 and 72 h in the bioreactor groups treated with either 200 or 500 microM GSNO compared with the control groups. Addition of an NO donor

  12. Modulatory role of Pterocarpus santalinus against alcohol-induced liver oxidative/nitrosative damage in rats.

    Science.gov (United States)

    Bulle, Saradamma; Reddy, Vaddi Damodara; Padmavathi, Pannuru; Maturu, Paramahamsa; N Ch, Varadacharyulu

    2016-10-01

    Pterocarpus santalinus, a traditional medicinal plant has shown protective mechanisms against various complications. The aim of the present study is to evaluate therapeutic efficacy of P. santalinus heartwood methanolic extract (PSE) against alcohol-induced oxidative/nitrosative stress leading to hepatotoxicity. In-vitro studies revealed that PSE possess strong DPPH (1,1-diphenyl-2-picryl hydrazyl) and nitric oxide radical scavenging activity. For in vivo studies male albino Wistar rats were treated with 20% alcohol (5g/kg b.wt/day) and PSE (250mg/kg b.wt/day) for 60days. Results showed that alcohol administration significantly altered plasma lipid profile with marked increase in the levels of plasma transaminases (ALT and AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and gamma glutamyl transferase (γGT). Moreover, lipid peroxides, nitric oxide (NOx) levels in plasma and liver were increased with increased iNOS protein expression in liver was noticed in alcohol administered rats and these levels were significantly brought back close to normal level by PSE administration except iNOS protein expression. Alcohol administration also decreased the content of reduced glutathione (GSH) and activities of glutathione peroxidase (GPx), glutathione-s transferase (GST), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT) in liver, which were significantly enhanced by administration of PSE. The active compounds pterostilbene, lignan and lupeols present in PSE might have shown protection against alcohol-induced hepatic damage by possibly reducing the rate of lipid peroxidation, NOx levels and increasing the antioxidant defence mechanism in alcohol administered rats. Both biochemical and histopathological results in the alcohol-induced liver damage model emphasize beneficial action of PSE as a hepatoprotective agent. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Chimeric mice with a humanized liver as an animal model of troglitazone-induced liver injury.

    Science.gov (United States)

    Kakuni, Masakazu; Morita, Mayu; Matsuo, Kentaro; Katoh, Yumiko; Nakajima, Miki; Tateno, Chise; Yokoi, Tsuyoshi

    2012-10-02

    Troglitazone (Tro) is a thiazolidinedione antidiabetic drug that was withdrawn from the market due to its association with idiosyncratic severe liver injury. Tro has never induced liver injury in experimental animals in vivo. It was assumed that the species differences between human and experimental animals in the pharmaco- or toxicokinetics of Tro might be associated with these observations. In this study, we investigated whether a chimeric mouse with a humanized liver that we previously established, whose replacement index with human hepatocytes is up to 92% can reproduce Tro-induced liver injury. When the chimeric mice were orally administered Tro for 14 or 23 days (1000mg/kg/day), serum alanine aminotransferase (ALT) was significantly increased by 2.1- and 3.6-fold, respectively. Co-administration of l-buthionine sulfoximine (10mM in drinking water), an inhibitor of glutathione (GSH) synthesis, unexpectedly prevented the Tro-dependent increase of ALT, which suggests that the GSH scavenging pathway will not be involved in Tro-induced liver injury. To elucidate the mechanism of the onset of liver injury, hepatic GSH content, the level of oxidative stress markers and phase I and phase II drug metabolizing enzymes were determined. However, these factors were not associated with Tro-induced liver injury. An immune-mediated reaction may be associated with Tro-induced liver toxicity in vivo, because the chimeric mouse is derived from an immunodeficient SCID mouse. In conclusion, we successfully reproduced Tro-induced liver injury using chimeric mice with a humanized liver, which provides a new animal model for studying idiosyncratic drug-induced liver injury. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  14. Telocytes in Pregnancy-Induced Physiological Liver Growth

    Directory of Open Access Journals (Sweden)

    Fei Wang

    2015-05-01

    Full Text Available Background/Aims: We previously documented the presence of Telocytes (TCs in liver and further indicated the potential roles of TCs in liver regeneration after hepatectomy. Pregnancy-induced liver growth, other than liver regeneration after hepatectomy, is a physiological hepatic adaption to meet the enhanced nutritional and metabolic demands. However, the possible roles of TCs in pregnancy-induced liver growth remain unknown. Methods: Pregnant mice were sacrificed at different time points (pregnancy day 0.5, 4.5, 8.5, 10.5, 12.5, 14.5, 16.5, and 18.5. The liver weight was used to evaluate the liver growth during pregnancy. Hepatocytes proliferation was determined by albumin and 5-ethynyl-2'- deoxyuridine (EdU double immunostaining while TCs were counted by double immunolabeling for CD34/PDGFR-α. Results: Pregnancy-induced liver growth was preceded by increased proliferation of hepatocytes at pregnancy day 4.5, 8.5, 14.5 and 16.5. Furthermore, the number of TCs in liver detected by double immunolabeling for CD34/PDGFR-α was significantly increased at pregnancy day 4.5 and day 14.5, that was coincident with the occurrence of two peaks of hepatic cell proliferation during pregnancy. Conclusion: Our results suggest a possible relationship between TCs and hepatocyte proliferation in pregnancy-induced liver growth.

  15. Partial deletion of argininosuccinate synthase protects from pyrazole plus lipopolysaccharide-induced liver injury by decreasing nitrosative stress.

    Science.gov (United States)

    Lu, Yongke; Leung, Tung Ming; Ward, Stephen C; Nieto, Natalia

    2012-02-01

    Argininosuccinate synthase (ASS) is the rate-limiting enzyme in the urea cycle. Along with nitric oxide synthase (NOS)-2, ASS endows cells with the L-citrulline/nitric oxide (NO·) salvage pathway to continually supply L-arginine from L-citrulline for sustained NO· generation. Because of the relevant role of NOS in liver injury, we hypothesized that downregulation of ASS could decrease the availability of intracellular substrate for NO· synthesis by NOS-2 and, hence, decrease liver damage. Previous work demonstrated that pyrazole plus LPS caused significant liver injury involving NO· generation and formation of 3-nitrotyrosine protein adducts; thus, wild-type (WT) and Ass+/- mice (Ass+/+ mice are lethal) were treated with pyrazole plus LPS, and markers of nitrosative stress, as well as liver injury, were analyzed. Partial ablation of Ass protected from pyrazole plus LPS-induced liver injury by decreasing nitrosative stress and hepatic and circulating TNFα. Moreover, apoptosis was prevented, since pyrazole plus LPS-treated Ass+/- mice showed decreased phosphorylation of JNK; increased MAPK phosphatase-1, which is known to deactivate JNK signaling; and lower cleaved caspase-3 than treated WT mice, and this was accompanied by less TdT-mediated dUTP nick end labeling-positive staining. Lastly, hepatic neutrophil accumulation was almost absent in pyrazole plus LPS-treated Ass+/- compared with WT mice. Partial Ass ablation prevents pyrazole plus LPS-mediated liver injury by reducing nitrosative stress, TNFα, apoptosis, and neutrophil infiltration.

  16. Organ damage in zymosan-induced multiple organ dysfunction syndrome in mice is not mediated by inducible nitric oxide synthase.

    NARCIS (Netherlands)

    Volman, T.J.H.; Goris, R.J.A.; Jagt, M. van der; Loo, F.A.J. van de; Hendriks, T.

    2002-01-01

    OBJECTIVE: To examine the role of inducible nitric oxide synthase (iNOS) in the development of the multiple organ dysfunction syndrome (MODS) in a murine model by using either a selective iNOS inhibitor or iNOS knockout mice. DESIGN: Prospective randomized laboratory study. SETTING: Central animal

  17. [The role of nitric oxide in ethylene-induced stomatal closure in Vicia faba L].

    Science.gov (United States)

    Li, Jie; Qiu, Li-Yan; Zhao, Fang-Gui; Hou, Li-Xia; Liu, Xin

    2007-08-01

    The effects of nitric oxide (NO) and ethylene on Vicia faba L. stomatal movement were studied. The results showed that NO donor SNP (sodium nitroprusside) 10 micromol/L and ethylene 0.04% could induce stomatal closure distinctly and they could promote stomatal closure when treated together. When treated with AVG (an inhibitor of ethylene synthesis), c-PTIO (a specific scavenger of NO) and NaN(3) (an inhibitor of NR), the effects of NO- and ethylene-induced stomatal closure were inhibited but the inhibitor of nitric oxide synthase (NOS) had little effect. We presumed that there was coordinative effect between NO and ethylene in regulation of stomatal closure; ethylene could induce stomatal closure by regulating the production of nitrate reductase (NR)-dependent NO.

  18. Nitric Oxide-Induced Polycystic Ovaries in The Wistar Rat

    Directory of Open Access Journals (Sweden)

    Fatemeh Hassani

    2012-01-01

    Full Text Available Background: Nitric oxide (NO involves in polycystic ovary syndrome (PCOS, a causeof infertility in women during the reproductive age. The PCOS is now categorized as aninflammatory phenomenon. The aim of this study was to evaluate the role of NO, a proinflammatoryagent, in this syndrome at histological and biochemical levels.Materials and Methods: In this experimental study, animals were female Wistar rats(weighing 200-250 g kept under standard conditions. L-Arginine (50-200 mg/kg, a precursorof NO, was injected intra-peritoneally (i.p. through a period ranging from 9 to14 days/once a day. The rats' estrous cycle was studied using Papanicolaou test; those showing phaseof Diestrous were grouped into experimental and control groups. The control group solelyreceived saline (1 ml/kg, i.p. throughout all experiments. To evaluate the inflammatory effectof NO, the rats were treated an anti-inflammatory agent, naloxone hydrochloride (0.4 mg/kg,i.p., prior to L-arginine. At the end of the treatment period all animals’ ovaries were assessedfor histopathological and histochemical investigations. Also, activation of NO synthase (NOSin the experiments was studied using NADPH-diaphorase technique.Results: The ovaries of rats treated with L-arginine showed polycystic characteristics incontrast to those collected from control or naloxone pretreated groups, based on image analysis.A difference in enzyme activation was also shown in the sections that belonged to thegroups that received L-arginine when compared with the pre-naloxone and control groups.Conclusion: Based on these results, we believe that NO may play a major role in thepathophysiology of PCOS.

  19. Expression of inducible nitric oxide synthase and effects of L-arginine on colonic nitric oxide production and fluid transport in patients with "minimal colitis"

    DEFF Research Database (Denmark)

    Perner, Anders; Andresen, Lars; Normark, Michel;

    2005-01-01

    Some patients with idiopathic, chronic diarrhoea have minimal, non-specific colonic inflammation. As nitric oxide (NO) acts as a secretagogue in the colon, we studied the expression of inducible NO synthase (iNOS) in mucosal biopsies and the effects of NOS stimulation on colonic transfer of fluid...

  20. Acute liver injury induced by weight-loss herbal supplements.

    Science.gov (United States)

    Chen, Gary C; Ramanathan, Vivek S; Law, David; Funchain, Pauline; Chen, George C; French, Samuel; Shlopov, Boris; Eysselein, Viktor; Chung, David; Reicher, Sonya; Pham, Binh V

    2010-11-27

    We report three cases of patients with acute liver injury induced by weight-loss herbal supplements. One patient took Hydroxycut while the other two took Herbalife supplements. Liver biopsies for all patients demonstrated findings consistent with drug-induced acute liver injury. To our knowledge, we are the first institute to report acute liver injury from both of these two types of weight-loss herbal supplements together as a case series. The series emphasizes the importance of taking a cautious approach when consuming herbal supplements for the purpose of weight loss.

  1. A randomized clinical trial testing the anti-inflammatory effects of preemptive inhaled nitric oxide in human liver transplantation.

    Directory of Open Access Journals (Sweden)

    John D Lang

    Full Text Available Decreases in endothelial nitric oxide synthase derived nitric oxide (NO production during liver transplantation promotes injury. We hypothesized that preemptive inhaled NO (iNO would improve allograft function (primary and reduce complications post-transplantation (secondary. Patients at two university centers (Center A and B were randomized to receive placebo (n = 20/center or iNO (80 ppm, n = 20/center during the operative phase of liver transplantation. Data were analyzed at set intervals for up to 9-months post-transplantation and compared between groups. Patient characteristics and outcomes were examined with the Mann-Whitney U test, Student t-test, logistic regression, repeated measures ANOVA, and Cox proportional hazards models. Combined and site stratified analyses were performed. MELD scores were significantly higher at Center B (22.5 vs. 19.5, p<0.0001, surgical times were greater at Center B (7.7 vs. 4.5 hrs, p<0.001 and warm ischemia times were greater at Center B (95.4 vs. 69.7 min, p<0.0001. No adverse metabolic or hematologic effects from iNO occurred. iNO enhanced allograft function indexed by liver function tests (Center B, p<0.05; and p<0.03 for ALT with center data combined and reduced complications at 9-months (Center A and B, p = 0.0062, OR = 0.15, 95% CI (0.04, 0.59. ICU (p = 0.47 and hospital length of stay (p = 0.49 were not decreased. iNO increased concentrations of nitrate (p<0.001, nitrite (p<0.001 and nitrosylhemoglobin (p<0.001, with nitrite being postulated as a protective mechanism. Mean costs of iNO were $1,020 per transplant. iNO was safe and improved allograft function at one center and trended toward improving allograft function at the other. ClinicalTrials.gov with registry number 00582010 and the following URL:http://clinicaltrials.gov/show/NCT00582010.

  2. Protective effect of nitric oxide against arsenic-induced oxidative ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-03-15

    Mar 15, 2010 ... alleviating arsenic-induced oxidative damage in tall fescue leaves were investigated. Arsenic (25 ... and it is distributed widely in natural environment. It occurred in a ... fertilizers, pesticides and sewage (Roberto et al., 2002).

  3. Evidence that nitric oxide synthase is involved in progesterone-induced acrosomal exocytosis in mouse spermatozoa.

    Science.gov (United States)

    Herrero, M B; Viggiano, J M; Pérez Martínez, S; de Gimeno, M F

    1997-01-01

    In a recent work, we detected nitric oxide synthase (NO synthase) in the acrosome and tail of mouse and human spermatozoa by an immunofluorescence technique. Also, NO-synthase inhibitors added during sperm capacitation in vitro reduced the percentage of oocytes fertilized in vitro, suggesting a role for NO synthase in sperm function. Therefore, in the present study the effect of three NO-synthase inhibitors, NG-nitro-L-arginine methyl ester (L-NAME), NG-nitro-D-arginine methyl ester (D-NAME) and L-NG-nitro-arginine (NO2-arg), and of a nitric oxide donor, spermine-NONOate, on the progesterone-induced acrosome reaction of mouse sperm was examined. NO-synthase inhibitors were added at 0, 60 or 90 min during capacitation; at 120 min, mouse epididymal spermatozoa were exposed to 15 microM progesterone for another 15 min. In another set of experiments, different concentrations of spermine-NONOate were added to capacitated spermatozoa for 15 min; in these experiments, progesterone was not included. NO2-arg and L-NAME blocked progesterone-induced exocytosis regardless of the time at which these inhibitors were added. Moreover, D-NAME did not inhibit exocytosis. In contrast, spermine-NONOate stimulated the acrosomal exocytosis in vitro directly. These results provide evidence that mouse sperm NO synthase participates in the progesterone-induced acrosome reaction in vitro and that nitric oxide induces this event.

  4. Nitric oxide (NO) inhibits antigen-stimulated increases in vasoconstriction and glycogenolysis in perfused livers derived from sensitized rats

    Energy Technology Data Exchange (ETDEWEB)

    Hines, K.L.; Bates, J.N.; Fisher, R.A. (Univ. of Iowa, Iowa City (United States))

    1991-03-11

    Recent studies in the authors laboratory demonstrated that infusion of antigen into perfused livers from sensitized rats produces increases in hepatic portal pressure, increases in hepatic glucose output and decreases in hepatic oxygen consumption. In the present study, effects of NO on these hepatic responses to antigen challenge were investigated. Infusion of NO into perfused livers from sensitized rats attenuated ovalbumin induced increases in hepatic portal pressure and glucose output approximately 85% and 90%, respectively, and abolished ovalbumin-induced decreases in hepatic oxygen consumption. The duration of ovalbumin-stimulated increases in hepatic portal pressure was reduced nearly 90% by NO. Similarly, infusion of NO into perfused livers from sensitized rats inhibited increases in hepatic portal pressure and glucose output in response to platelet-activating factor (PAF) nearly 80 and 90%, respectively. In contrast, NO inhibited completely hepatic vasoconstriction in response to phenylephrine without altering glycogenolytic responses to this {alpha}-adrenergic agonist. These results provide evidence for regulatory effects of NO on hemodynamic and glycogenolytic responses to antigen in perfused livers from sensitized rats. These observations support previous findings which suggest that hepatic responses to sensitizing antigen may be mediated by PAF or other autacoid mediators which stimulate glycogenolysis in liver by indirect mechanisms involving hepatic vasoconstriction.

  5. Chronic administration of fluoxetine or clozapine induces oxidative stress in rat liver: a histopathological study.

    Science.gov (United States)

    Zlatković, Jelena; Todorović, Nevena; Tomanović, Nada; Bošković, Maja; Djordjević, Snežana; Lazarević-Pašti, Tamara; Bernardi, Rick E; Djurdjević, Aleksandra; Filipović, Dragana

    2014-08-01

    Chronic exposure to stress contributes to the etiology of mood disorders, and the liver as a target organ of antidepressant and antipsychotic drug metabolism is vulnerable to drug-induced toxicity. We investigated the effects of chronic administration of fluoxetine (15mg/kg/day) or clozapine (20mg/kg/day) on liver injury via the measurement of liver enzymes, oxidative stress and histopathology in rats exposed to chronic social isolation (21days), an animal model of depression, and controls. The activity of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), the liver content of carbonyl groups, malonyldialdehyde (MDA), reduced glutathione (GSH), cytosolic glutathione S-transferase (GST) and nitric oxide (NO) metabolites were determined. We also characterized nuclear factor-κB (NF-κB), cyclooxygenase-2 (COX-2) and CuZn-superoxide dismutase (CuZnSOD) protein expression as well as histopathological changes. Increased serum ALT activity in chronically-isolated and control animals treated with both drugs was found while increased AST activity was observed only in fluoxetine-treated rats (chronically-isolated and controls). Increased carbonyl content, MDA, GST activity and decreased GSH levels in drug-treated controls/chronically-isolated animals suggest a link between drugs and hepatic oxidative stress. Increased NO levels associated with NF-κB activation and the concomitant increased COX-2 expression together with compromised CuZnSOD expression in clozapine-treated chronically-isolated rats likely reinforce oxidative stress, observed by increased lipid peroxidation and GSH depletion. In contrast, fluoxetine reduced NO levels in chronically-isolated rats. Isolation induced oxidative stress but histological changes were similar to those observed in vehicle-treated controls. Chronic administration of fluoxetine in both chronically-isolated and control animals resulted in more or less normal hepatic architecture, while clozapine in both groups

  6. Epigallocatechin-3-Gallate Ameliorates Alcohol-Induced Liver Injury in Rats

    Directory of Open Access Journals (Sweden)

    Xi Li

    2006-07-01

    Full Text Available Endotoxemia is a common event in alcoholic liver disease. Elevated intestinalpermeability is the major factor involved in the mechanism of alcoholic endotoxemia andthe pathogenesis of alcoholic liver disease. This study examined the effect ofepigallocatechin-3-gallate (EGCG on alcohol-induced gut leakiness, and explored therelated mechanisms involved in its protection against alcohol-induced liver injury in rats.Four groups of female Sprague-Dawley rats were studied. Alcohol and alcohol/EGCGgroups rats received fish oil along with alcohol daily via gastrogavage for 6 weeks, anddextrose and dextrose/EGCG groups rats were given fish oil along with isocaloric dextroseinstead of alcohol. The dextrose/EGCG and alcohol/EGCG groups received additionaltreatment of EGCG (100mg.kg-1 body weight daily intragastrically by gavage. Intestinalpermeability was assessed by urinary excretion of lactulose and mannitol (L/M ratio. Liverinjury was evaluated histologically and by serum alanine aminotransferase (ALT. Plasmaendotoxin and serum tumor necrosis factor-α (TNF-α levels were assayed; livermalondialdehyde (MDA contents determined. CD14 and inflammatory factors, such asTNF-α, cyclooxygenase-2 (COX-2 and inducible nitric oxide synthase (iNOS mRNAs inthe liver were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR. Ratsgiven fish oil plus alcohol had gut leakiness (L/M ratio was increased, which wasassociated with both endotoxemia and liver injury. The above responses were accompaniedby increased CD14, TNF-α, COX-2 and iNOS mRNA expressions in the liver. EGCGsupplementation partly blocked the gut leakiness, reduced endotoxemia and lipidperoxidation, and blunted the elevated expressions of CD14, TNF-α, COX-2 and iNOS, allof which were associated with improved liver injury. These results show that EGCG can block alcohol-induced gut leakiness, reduce endotoxemia, and inhibit inflammatory factors expressions in

  7. Fucoidan partly prevents CCl4-induced liver fibrosis

    OpenAIRE

    Hayashi, Shinji; Itoh, Ayano; Isoda, Katsuhiro; Kondoh, Masuo; KAWASE, Masaya; Yagi, Kiyohito

    2008-01-01

    Fucoidan, a sulfated polysaccharide extracted from brown algae, has a wide range of biological activities, including anti-inflammatory, anti-viral, and anti-tumor activities. In the present study, we investigated the effects of fucoidan on CCl4-induced liver fibrosis. Administration of fucoidan reduced CCl4-induced acute and chronic liver failure. Hepatic fibrosis induced by CCl4 was also attenuated by injection of fucoidan. Damage to hepatocytes and activation of hepatic stellate cells are k...

  8. BML-111 Protected LPS/D-GalN-Induced Acute Liver Injury in Rats

    Directory of Open Access Journals (Sweden)

    Dan Yan

    2016-07-01

    Full Text Available Lipoxins (LXs display unique pro-resolving and anti-inflammatory functions in a variety of inflammatory conditions. The present study was undertaken to investigate the effects of BML-111 (5(S,6(R,7-trihydroxyheptanoic acid methyl ester, the agonist of lipoxin A4 receptor, in a model of Lipopolysaccharides (LPS and d-Galactosamine (d-GalN induced acute liver injury, and to explore the mechanisms. Histopathological analyses were carried out to quantify liver injury degree. The activities of myeloperoxidase (MPO were examined to evaluate the levels of neutrophil infiltration. The activities of aspartate aminotransferase (AST and alanine aminotransferase (ALT in serum were detected to evaluate the functions of the liver. The amounts of tumor necrosis factor-α (TNF-α, interleukin-10 (IL-10, and interleukin-1β (IL-1β were measured using enzyme-linked immunosorbent assay (ELISA, and the expression levels of transforming growth factor-β1(TGF-β1 and cyclooxygenase-2 (COX-2 were examined using Western blotting. The antioxidant capacity, the activities of inducible nitric oxide synthase (iNOS, the contents of malondialdehyde (MDA and nitric oxide (NO were analyzed with the kits via biochemical analysis. We established the model of acute liver injury with lipopolysaccharide and d-Galactosamine (LPS/d-GalN: (1 histopathological results and MPO activities, with the activities of AST and ALT in serum, consistently demonstrated LPS and d-GalN challenge could cause severe liver damage, but BML-111 could prevent pathological changes, inhibit neutrophil infiltration, and improve the hepatic function; (2 LPS/d-GalN increased TNF-α, IL-1β, COX-2, and IL-10, while decreasing TGF-β1. However, BML-111 could repress LPS/d-GalN -induced TNF-α, IL-1β and COX-2, meanwhile increasing the expression levels of TGF-β1 and IL-10; (3 LPS/d-GalN inhibited the activities of superoxide dismutase (SOD, catalase (CAT, total antioxidant capacity (T-AOC, and hydroxyl

  9. Nitric oxide-induced changes in endothelial expression of phosphodiesterases 2, 3, and 5

    DEFF Research Database (Denmark)

    Schankin, Christoph J; Kruse, Lars S; Reinisch, Veronika M;

    2010-01-01

    line containing such PDEs. METHODS: Real time polymerase chain reaction and Western blots were used to show expression of PDE2A, PDE3B, and PDE5A in a stable cell line of human brain microvascular endothelial cells. Effects of NO on PDE expression were analyzed at specific time intervals after......OBJECTIVE: To investigate nitric oxide (NO)-mediated changes in expression of cyclic nucleotide degrading phosphodiesterases 2A (PDE2A), PDE3B, and PDE5A in human endothelial cells. BACKGROUND: Nitric oxide induces production of cyclic guanosine monophosphate (cGMP), which along with cyclic...... adenosine monophosphate (cAMP) is degraded by PDEs. NO donors and selective inhibitors of PDE3 and PDE5 induce migraine-like headache and play a role in endothelial dysfunction during stroke. The current study investigates possible NO modulation of cGMP-related PDEs relevant to headache induction in a cell...

  10. A review of drug-induced liver injury databases.

    Science.gov (United States)

    Luo, Guangwen; Shen, Yiting; Yang, Lizhu; Lu, Aiping; Xiang, Zheng

    2017-07-17

    Drug-induced liver injuries have been a major focus of current research in drug development, and are also one of the major reasons for the failure and withdrawal of drugs in development. Drug-induced liver injuries have been systematically recorded in many public databases, which have become valuable resources in this field. In this study, we provide an overview of these databases, including the liver injury-specific databases LiverTox, LTKB, Open TG-GATEs, LTMap and Hepatox, and the general databases, T3DB, DrugBank, DITOP, DART, CTD and HSDB. The features and limitations of these databases are summarized and discussed in detail. Apart from their powerful functions, we believe that these databases can be improved in several ways: by providing the data about the molecular targets involved in liver toxicity, by incorporating information regarding liver injuries caused by drug interactions, and by regularly updating the data.

  11. Central blockade of nitric oxide synthesis reduces moxonidine-induced hypotension

    OpenAIRE

    Moreira, Thiago Santos [UNIFESP; Takakura, Ana Carolina Thomaz [UNIFESP; Menani, José V.; Sato, Monica Akemi; Colombari, Eduardo

    2004-01-01

    1 Nitric oxide (NO) and alpha(2)-adrenoceptor and imidazoline agonists such as moxonidine may act centrally to inhibit sympathetic activity and decrease arterial pressure.2 In the present study, we investigated the effects of pretreatment with L-NAME ( NO synthesis inhibitor), injected into the 4th ventricle (4th V) or intravenously (i.v.), on the hypotension, bradycardia and vasodilatation induced by moxonidine injected into the 4th V in normotensive rats.3 Male Wistar rats with a stainless ...

  12. Gentamicin induced nitric oxide-related oxidative damages on vestibular afferents in the guinea pig.

    Science.gov (United States)

    Hong, Sung Hwa; Park, Sook Kyung; Cho, Yang-Sun; Lee, Hyun-Seok; Kim, Ki Ryung; Kim, Myung Gu; Chung, Won-Ho

    2006-01-01

    Gentamicin is a well-known ototoxic aminoglycoside. However, the mechanism underlying this ototoxicity remains unclear. One of the mechanisms which may be responsible for this ototoxicity is excitotoxic damage to hair cells. The overstimulation of the N-methyl-d-aspartate (NMDA) receptors increases the production of nitric oxide (NO), which induces oxidative stress on hair cells. In order to determine the mechanism underlying this excitotoxicity, we treated guinea pigs with gentamicin by placing gentamicin (0.5 mg) pellets into a round window niche. After the sacrifice of the animals, which occurred at 3, 7 and 14 days after the treatment, the numbers of hair cells in the animals were counted with a scanning electron microscope. We then performed immunostaining using neuronal nitric oxide synthase (nNOS), inducible NOS (iNOS) and nitrotyrosine antibodies. The number of hair cells in the animals was found to decrease significantly after 7 days. nNOS and iNOS expression levels were observed to have increased 3 days after treatment. Nitrotyrosine was expressed primarily at the calyceal afferents of the type I hair cells 3 days after treatment. Terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining revealed positive hair cells 3 days after treatment. Our results suggest that inner ear treatment with gentamicin may upregulate nNOS and iNOS to induce oxidative stress in the calyceal afferents of type I hair cells, via nitric oxide overproduction.

  13. Auxin-induced nitric oxide, cGMP and gibberellins were involved in the gravitropism

    Science.gov (United States)

    Cai, Weiming; Hu, Liwei; Hu, Xiangyang; Cui, Dayong; Cai, Weiming

    Gravitropism is the asymmetric growth or curvature of plant organs in response to gravistimulation. There is a complex signal transduction cascade which involved in the differential growth of plants in response to changes in the gravity vector. The role of auxin in gravitropism has been demonstrated by many experiments, but little is known regarding the molecular details of such effects. In our studies before, mediation of the gravitropic bending of soybean roots and rice leaf sheath bases by nitric oxide, cGMP and gibberellins, are induced by auxin. The asymmetrical distribution of nitric oxide, cGMP and gibberellins resulted from the asymmetrical synthesis of them in bending sites. In soybean roots, inhibitions of NO and cGMP synthesis reduced differential NO and cGMP accumulation respectively, which both of these effects can lead to the reduction of gravitropic bending. Gibberellin-induced OsXET, OsEXPA4 and OsRWC3 were also found involved in the gravitropic bending. These data indicated that auxin-induced nitric oxide, cGMP and gibberellins were involved in the gravitropism. More experiments need to prove the more detailed mechanism of them.

  14. Treatment of sunitinib-induced hypertension in solid tumor by nitric oxide donors☆

    Science.gov (United States)

    León-Mateos, L.; Mosquera, J.; Antón Aparicio, L.

    2015-01-01

    Vascular endothelial growth factor (VEGF) and its receptor (VEGFR) are overexpressed in the majority of renal cell carcinomas. This characteristic has supported the rationale of targeting VEGF-driven tumour vascularization, especially in clear cell RCC. VEGF-inhibiting strategies include the use of tyrosine kinase inhibitors (sunitinib, axitinib, pazopanib, and sorafenib) and neutralizing antibodies such as bevacizumab. Hypertension (HTN) is one of the most common adverse effects of angiogenesis inhibitors. HTN observed in clinical trials appears to correlate with the potency of VEGF kinase inhibitor against VEGFR-2: agents with higher potency are associated with a higher incidence of HTN. Although the exact mechanism by tyrosine kinase inhibitors induce HTN has not yet been completely clarified, two key hypotheses have been postulated. First, some studies have pointed to a VEGF inhibitors-induced decrease in nitric oxide synthase (NOS) and nitric oxide (NO) production, that can result in vasoconstriction and increased blood pressure. VEGF, mediated by PI3K/Akt and MAPK pathway, upregulates the endothelial nitric oxide synthase enzyme leading to up-regulation of NO production. So inhibition of signaling through the VEGF pathway would lead to a decrease in NO production, resulting in an increase in vascular resistance and blood pressure. Secondly a decrease in the number of microvascular endothelial cells and subsequent depletion of normal microvessel density (rarefaction) occurs upon VEGF signaling inhibition. NO donors could be successfully used not only for the treatment of developed angiogenesis-inhibitor-induced hypertension but also for preventive effects. PMID:26386874

  15. Lanthanum Chloride Inhibiting Expression of Inducible Nitric Oxide Synthase in RAW264.7 Macrophages Induced by Lipopolysaccharide

    Institute of Scientific and Technical Information of China (English)

    Guo Fei; Lou Yuanlei; Wang Yang; Xie An; Li Guohui

    2007-01-01

    Nitric oxide (NO) and its reaction products were key players in the pathophysiology of sepsis and shock. The present study was designed to explore the effects of lanthanum chloride (LaCl3) on inducible nitric oxide synthase (iNOS) expression, at both gene and protein levels, in RAW264.7 macrophages induced by Lipopolysaccharide (LPS). Reverse transcription polymerase chain reaction (RT-PCR), immunofluorescence, and western blot were employed to measure iNOS gene expression, localization, and protein expression respectively. NO production in culture supernatants was detected by the nitrate reductase method. The results showed that LaCl3 significantly attenuated the iNOS gene and protein expression, as well as NO production in RAW264.7cells induced by LPS.

  16. Amygdalin suppresses lipopolysaccharide-induced expressions of cyclooxygenase-2 and inducible nitric oxide synthase in mouse BV2 microglial cells.

    Science.gov (United States)

    Yang, Hye-Young; Chang, Hyun-Kyung; Lee, Jin-Woo; Kim, Young-Sick; Kim, Hong; Lee, Myoung-Hwa; Shin, Mal-Soon; Ham, Dae-Hyun; Park, Hun-Kuk; Lee, Hyejung; Kim, Chang-Ju

    2007-01-01

    Amygdalin (D-mandelonitrile-beta-D-gentiobioside) is a cynogenic compound found in sweet and bitter almonds, Persicae semen and Armeniacae semen. Amygdalin has been used for the treatment of cancers and for the relief of the pain. We made an aqueous extraction of amygdalin from Armeniacae semen. In this study, the effect of amygdalin on the lipopolysaccharide (LPS)-induced inflammation was investigated. The effects of amygdalin extracted from Armeniacae semen on the LPS-stimulated mRNA expressions of cyclooxygenase (COX)-1, COX-2 and inducible nitric oxide synthase (iNOS) in the mouse BV2 microglial cells were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, reverse transcription-polymerase chain reaction (RT-PCR). The effects of amygdalin on the prostaglandins E(2) synthesis and the nitric oxide production were also studied by performing prostaglandins E(2) immunoassay and by detecting nitric oxide. The present results showed that amygdalin suppressed the prostaglandin E(2) synthesis and the nitric oxide production by inhibiting the LPS-stimulated mRNA expressions of COX-2 and iNOS in the mouse BV2 cells. These results show that amygdalin exerts anti-inflammatory and analgesic effects and it dose so probably by suppressing the mRNA expressions of COX-2 and iNOS.

  17. Synthesis of N-(Methoxycarbonylthienylmethylthioureas and Evaluation of Their Interaction with Inducible and Neuronal Nitric Oxide Synthase

    Directory of Open Access Journals (Sweden)

    Michael D. Threadgill

    2010-04-01

    Full Text Available Two isomeric N-(methoxycarbonylthienylmethylthioureas were synthesised by a sequence of radical bromination of methylthiophenecarboxylic esters, substitution with trifluoroacetamide anion, deprotection, formation of the corresponding isothiocyanates and addition of ammonia. The interaction of these new thiophene-based thioureas with inducible and neuronal nitric oxide synthase was evaluauted. These novel thienylmethylthioureas stimulated the activity of inducible Nitric Oxide Synthase (iNOS.

  18. Oxidative stress in portal hypertension-induced rats with particular emphasis on nitric oxide and trace metals

    Institute of Scientific and Technical Information of China (English)

    Titiz Izzet; Genc Habibe; Aydin Seval; Simsek Gonul; Krand Osman; Unal Ethem; Yavuz Nihat; Kusaslan Ramazan; Dogan Mustafa; Uzun Hafize; Kiziler Ali Riza; Aydemir Birsen

    2005-01-01

    AIM: To investigate the oxidative-stress-related changes in rats with portal hypertension with particular emphasis on nitric oxide (NO) and trace metals. METHODS: Cirrhosis was induced by partial portal vein ligation (PVL) in Wistar rats. The lipid peroxidation marker (malondialdehyde, MDA), antioxidant defense enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and agents known to have antioxidant features including nitric oxide (NO), zinc (Zn), copper (Cu) were determined both in serum and in liver tissue at 4 wk after surgery in PVL and sham-operated rats. Portal pressure of all experimental animals was measured. MDA was detected by thiobarbituric acid reactivity assay.SOD activity was determined by inhibition of nitroblue tetrazolium reduction with xanthine/xanthine oxidase used asa superoxide generator. CAT activity was determined by the breakdown of hydrogen peroxide. GSH concentrations were measured by using metaphosphoric acid for protein precipitation and 5'-5'-dithio-bis-2-nitrobenzoic acid for color development. NO was detected by the Griess method after reduction of nitrate to nitrite with nitrate reductase, and the concentrations of Zn and Cu were measured by a Shimadzu 680 AA atomic absorption spectrometer. Histopathological confirmation was done under light microscope. Statistical analyses were done by Student's t-test, and significance of the difference was tested by the unpaired Mann-Whitney test. P<0.05 was considered statistically significant.RESULTS: Histopathological studies confirmed PVL induced cirrhotic changes. There was a statistically significant difference in portal pressure between PVL and control groups (P<0.001). The results showed significant increases in the levels of MDA and NO in both tissue and serum (P<0.05 and P<0.001, respectively in tissue; P<0.001 for each in serum), and Zn only in tissue (P<0.001)in rats with PVL compared with sham-operated rats. Besides, PVL rats exhibited reduced

  19. Acetaminophen-induced acute liver injury in HCV transgenic mice

    Energy Technology Data Exchange (ETDEWEB)

    Uehara, Takeki; Kosyk, Oksana; Jeannot, Emmanuelle; Bradford, Blair U. [Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC 27599 (United States); Tech, Katherine; Macdonald, Jeffrey M. [Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC 27599 (United States); Boorman, Gary A. [Covance, Chantilly, VA 20151 (United States); Chatterjee, Saurabh; Mason, Ronald P. [Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, RTP, NC 27713 (United States); Melnyk, Stepan B. [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR 72201 (United States); Tryndyak, Volodymyr P.; Pogribny, Igor P. [Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR 72079 (United States); Rusyn, Ivan, E-mail: iir@unc.edu [Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC 27599 (United States)

    2013-01-15

    The exact etiology of clinical cases of acute liver failure is difficult to ascertain and it is likely that various co-morbidity factors play a role. For example, epidemiological evidence suggests that coexistent hepatitis C virus (HCV) infection increased the risk of acetaminophen-induced acute liver injury, and was associated with an increased risk of progression to acute liver failure. However, little is known about possible mechanisms of enhanced acetaminophen hepatotoxicity in HCV-infected subjects. In this study, we tested a hypothesis that HCV-Tg mice may be more susceptible to acetaminophen hepatotoxicity, and also evaluated the mechanisms of acetaminophen-induced liver damage in wild type and HCV-Tg mice expressing core, E1 and E2 proteins. Male mice were treated with a single dose of acetaminophen (300 or 500 mg/kg in fed animals; or 200 mg/kg in fasted animals; i.g.) and liver and serum endpoints were evaluated at 4 and 24 h after dosing. Our results suggest that in fed mice, liver toxicity in HCV-Tg mice is not markedly exaggerated as compared to the wild-type mice. In fasted mice, greater liver injury was observed in HCV-Tg mice. In fed mice dosed with 300 mg/kg acetaminophen, we observed that liver mitochondria in HCV-Tg mice exhibited signs of dysfunction showing the potential mechanism for increased susceptibility. -- Highlights: ► Acetaminophen-induced liver injury is a significant clinical challenge. ► HCV-infected subjects may be at higher risk for acetaminophen-induced liver injury. ► We used HCV transgenics to test if liver injury due to acetaminophen is exacerbated.

  20. Osteopontin protects against hyperoxia-induced lung injury by inhibiting nitric oxide synthases.

    Science.gov (United States)

    Zhang, Xiang-Feng; Liu, Shuang; Zhou, Yu-Jie; Zhu, Guang-Fa; Foda, Hussein D

    2010-04-05

    Exposure of adult mice to more than 95% O(2) produces a lethal injury by 72 hours. Nitric oxide synthase (NOS) is thought to contribute to the pathophysiology of murine hyperoxia-induced acute lung injury (ALI). Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages. OPN inhibits inducible nitric oxide synthase (iNOS), which generates large amounts of nitric oxide production. However, the relationship between nitric oxide and endogenous OPN in lung tissue during hyperoxia-induced ALI has not yet been elucidated, thus we examined the role that OPN plays in the hyperoxia-induced lung injury and its relationships with NOS. One hundred and forty-four osteopontin knock-out (KO) mice and their matched wild type background control (WT) were exposed in sealed cages > 95% oxygen or room air for 24- 72 hours, and the severity of lung injury was assessed; expression of OPN, endothelial nitric oxide synthase (eNOS) and iNOS mRNA in lung tissues at 24, 48 and 72 hours of hyperoxia were studied by reverse transcription-polymerase chain reaction (RT-PCR); immunohistochemistry (IHC) was performed for the detection of iNOS, eNOS, and OPN protein in lung tissues. OPN KO mice developed more severe acute lung injury at 72 hours of hyperoxia. The wet/dry weight ratio increased to 6.85 +/- 0.66 in the KO mice at 72 hours of hyperoxia as compared to 5.31 +/- 0.92 in the WT group (P < 0.05). iNOS mRNA (48 hours: 1.04 +/- 0.08 vs. 0.63 +/- 0.09, P < 0.01; 72 hours: 0.89 +/- 0.08 vs. 0.72 +/- 0.09, P < 0.05) and eNOS mRNA (48 hours: 0.62 +/- 0.08 vs. 0.43 +/- 0.09, P < 0.05; 72 hours: 0.67 +/- 0.08 vs. 0.45 +/- 0.09, P < 0.05) expression was more significantly increased in OPN KO mice than their matched WT mice when exposed to hyperoxia. IHC study showed higher expression of iNOS (20.54 +/- 3.18 vs. 12.52 +/- 2.46, P < 0.05) and eNOS (19.83 +/- 5.64 vs. 9.45 +/- 3.82, P < 0.05) in lung tissues of OPN KO mice at 72 hours of hyperoxia. OPN can protect against

  1. Severe liver injury induced by repeated use of hair dye

    Institute of Scientific and Technical Information of China (English)

    HOU Feng-qin; LIN Xiao-hong; YU Yan-yan; WANG Tai-ling; WANG Gui-qiang

    2009-01-01

    @@ Asignificant number of drugs has been proven,or at least suggested,to cause hepatotoxicity.1-3 Liver injury due to herbal medicines,chemicals or natural toxins also occur from household,occupational,or environmental exposure.4,5 However,liver toxicity due to hair dyes now is rarely recognized.Only in 2003,Tokumoto et al6 reported a case of hair dye-induced hepatitis,which presented a comparatively mild liver lesion.Here we described a case had more severe liver injury.

  2. Expression of Endothelial Nitric Oxide Synthase Traffic Inducer in the Placenta of Pregnancy Induced Hypertension

    Institute of Scientific and Technical Information of China (English)

    XIANG Wenpei; CHEN Hanping; GUO Yuzhen; SHEN Hongling

    2006-01-01

    The expression of endothelial nitric oxide synthase traffic inducer (NOSTRIN) in the placenta of the patients with pregnancy induced hypertension (PIH) was detected and its role in the pathogenesis of PIH was studied. The pathological changes in placental vessels were observed by HE staining. NO2-/NO3- , the stable metabolic end products of NO, was measured with nitrate reductase. The eNOS activity in placental tissues was assayed by spectrophotometry. Western blot analysis was applied to detect NOSTRIN expression. The incidence of thickening and fibronoid necrosis of placental vessels was significantly higher in women with PIH than in the normal group (P<0.01). The levels of placental NO2-/NO3- in PIH patients (27.53±7.48 μmol/mg) were significantly lower than in normal group (54.27±9.53 μmol/mg, P<0.01). The activity of eNOS was significantly decreased in PIH group (12. 826±3.61 U/mg) as compared with that in normal group (21. 72±3.83 U/mg, P<0.01). Western blot analysis revealed that both groups expressed 58 kD NOSTRIN, but the protein level was significantly higher in women with PIH than in the normal group (P<0.01). A significant negative correlation existed between the expression of NOSTRIN protein and the activity of eNOS in placental tissue of women with PIH (r=-0. 57, P<0. 01). It was concluded that the level of NOSTRIN expression in placenta of women with PIH was increased, which may play an important role in the pathogenesis of PIH.

  3. Gomisin N in the herbal drug gomishi (Schisandra chinensis) suppresses inducible nitric oxide synthase gene via C/EBPβ and NF-κB in rat hepatocytes.

    Science.gov (United States)

    Takimoto, Yuna; Qian, Hai-Yan; Yoshigai, Emi; Okumura, Tadayoshi; Ikeya, Yukinobu; Nishizawa, Mikio

    2013-01-15

    Gomishi is the dried fruit of Schisandra chinensis Baillon (Fructus Schisandrae chinensis, FSC) and has been used in Japanese Kampo medicine to treat inflammatory and liver diseases. However, it is unclear which constituent of FSC is primarily responsible for its pharmacological effects. FSC was extracted with methanol, fractionated by hydrophobicity, and further purified. We measured the effects of each fraction or constituent thereof on the induction of the inflammatory mediator nitric oxide (NO), which was induced by interleukin 1β in primary cultured rat hepatocytes. The hydrophobic fraction markedly suppressed NO induction and reduced the expression of inducible nitric oxide syntheses (iNOS) in interleukin 1β-treated hepatocytes. Gomisin N and γ-schizandrin, two major constituents of the hydrophobic fraction, significantly reduced NO production and the levels of the iNOS protein, mRNA, and antisense transcript. Gomisin N and γ-schizandrin also decreased the transcription of interleukin 1β and inflammatory chemokines. The overexpression of the p65 subunit of nuclear factor κB or CCAAT/enhancer-binding protein β increased the promoter activity of the iNOS gene in the firefly luciferase assay, whereas gomisin N decreased the promoter activity. The anti-inflammatory activity of FSC and its constituents were analysed, and we demonstrated that gomisin N and γ-schizandrin are involved in the hepatoprotective effect of the FSC extract, which has therapeutic potential for liver disease.

  4. Effects of thyroid dysfunction-induced liver oxidative

    African Journals Online (AJOL)

    Unicornis

    of micronutrients such as selenium (Se) and zinc (Zn) prevented MD-induced hepatic damage. Rats ..... Acute exposure to pesticides can cause oxidative damage. The current ..... Effect of chronic intake of arsenic contaminated water on liver.

  5. The antioxidant tempol decreases acute pulmonary thromboembolism-induced hemolysis and nitric oxide consumption.

    Science.gov (United States)

    Sousa-Santos, Ozelia; Neto-Neves, Evandro M; Ferraz, Karina C; Sertório, Jonas T; Portella, Rafael L; Tanus-Santos, Jose E

    2013-11-01

    Acute pulmonary thromboembolism (APT) is a critical condition associated with acute pulmonary hypertension. Recent studies suggest that oxidative stress and hemolysis contribute to APT-induced pulmonary hypertension, possibly as a result of increased nitric oxide (NO) consumption. We hypothesized that the antioxidant tempol could attenuate APT-induced hemolysis, and therefore attenuate APT-induced increases in plasma NO consumption. APT was induced in anesthetized sheep with autologous blood clots. The hemodynamic effects of tempol infused at 1.0mg/kg/min 30 min after APT were determined. Hemodynamic measurements were carried out every 15 min. To assess oxidative stress, serum 8-isoprostanes levels were measured by ELISA. Plasma cell-free hemoglobin concentrations and NO consumption by plasma samples were determined. An in vitro oxidative AAPH-induced hemolysis assay was used to further validate the in vivo effects of tempol. APT caused pulmonary hypertension, and increased pulmonary vascular resistance in proportion with the increases in 8-isoprostanes, plasma cell-free hemoglobin concentrations, and NO consumption by plasma (all Phemolysis (Phemolysis and nitric oxide consumption, thus attenuating APT-induced pulmonary hypertension. © 2013.

  6. The endogenous nitric oxide mediates selenium-induced phytotoxicity by promoting ROS generation in Brassica rapa.

    Directory of Open Access Journals (Sweden)

    Yi Chen

    Full Text Available Selenium (Se is suggested as an emerging pollutant in agricultural environment because of the increasing anthropogenic release of Se, which in turn results in phytotoxicity. The most common consequence of Se-induced toxicity in plants is oxidative injury, but how Se induces reactive oxygen species (ROS burst remains unclear. In this work, histofluorescent staining was applied to monitor the dynamics of ROS and nitric oxide (NO in the root of Brassica rapa under Se(IV stress. Se(IV-induced faster accumulation of NO than ROS. Both NO and ROS accumulation were positively correlated with Se(IV-induced inhibition of root growth. The NO accumulation was nitrate reductase (NR- and nitric oxide synthase (NOS-dependent while ROS accumulation was NADPH oxidase-dependent. The removal of NO by NR inhibitor, NOS inhibitor, and NO scavenger could alleviate Se(IV-induced expression of Br_Rbohs coding for NADPH oxidase and the following ROS accumulation in roots, which further resulted in the amelioration of Se(IV-induced oxidative injury and growth inhibition. Thus, we proposed that the endogenous NO played a toxic role in B. rapa under Se(IV stress by triggering ROS burst. Such findings can be used to evaluate the toxic effects of Se contamination on crop plants.

  7. Nitric oxide signals postovulatory aging-induced abortive spontaneous egg activation in rats.

    Science.gov (United States)

    Premkumar, Karuppanan V; Chaube, Shail K

    2015-07-01

    The aim of this study was to determine whether an increase of intracellular nitric oxide (NO) level signals postovulatory aging-induced abortive spontaneous egg activation (SEA) in rats. Freshly ovulated eggs (arrested at metaphase-II stage; M-II) were cultured in vitro for 3 hours to induce postovulatory egg aging. The morphological changes, inducible nitric oxide synthase (iNOS) expression, NO, cytosolic free Ca(2+), 3',5' cyclic guanosine monophosphate (cGMP), cell division cycle 25B (Cdc25B) and Wee1 levels, specific phosphorylation (pThr-14/Tyr-15) as well as total cyclin-dependent kinases-1 (Cdk1) (PSTAIRE) levels were analyzed. Postovulatory aging induced generation of NO possibly through an iNOS-mediated pathway. The increase in NO level was associated with augmented cytosolic free Ca(2+) as well as cGMP levels in aged eggs. A significant increase in Wee1 level and decrease of Cdc25B level were observed in aged eggs. An accumulation of phosphorylated Cdk1 (pThr-14/Tyr-15) level was observed in aged eggs, while total Cdk1 (PSTAIR) level remained unchanged. Our study demonstrates that generation of NO through an iNOS-mediated pathway increases cytosolic free Ca2+and cGMP levels. High levels of these signal molecules trigger the accumulation of phosphorylated Cdk1 in aged eggs. Thus, NO signals the accumulation of phosphorylated Cdk1 and induces postovulatory aging-induced abortive SEA in the rat.

  8. Nitric oxide as a carcinogen. Analysis by yeast functional assay of inactivating p53 mutations induced by nitric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Murata, Jun-Ichi; Tada, Mitsuhiro; Sawamura, Yutaka; Shinohe, Yumiko; Abe, Hiroshi [Laboratory for Molecular Brain Research, Department of Neurosurgery, Hokkaido University School of Medicine, Sapporo (Japan); Iggo, Richard D. [Oncogene group, Swiss Institute for Experimental Cancer Research ISREC, Epalinges (Switzerland)

    1997-10-06

    We have used a yeast p53 functional assay to study induction of mutations in the p53 tumor suppressor gene by nitric oxide and cytosine methylation. The yeast assay identifies only biologically important p53 mutations. p53 cDNA was treated with the nitric oxide donor sydnonimine, PCR-amplified and transfected into yeast. Sydnonimine produced a significant, dose-dependent increase in C:G->A:T transversions. Many important p53 mutational hotspots are postulated to arise by deamination of methylCpG in tumors. We therefore examined nitric oxide induction of mutations in p53 cDNA methylated by PCR-mediated substitution of 5-methylcytosine for cytosine or by treatment with the SssI CpG methylase. Both methylation procedures increased the baseline mutation rate, and nitric oxide treatment produced a further increase in mutation yield. Sequence analysis showed that methylation alone led to C:G->T:A transitions, whereas nitric oxide treatment simply produced more C:G->A:T transversions. Thus the most important factor in C:G->T:A transition at CpG sites identified in this experimental system is cytosine methylation, consistent with spontaneous conversion of 5-methylcytosine to thymine by deamination

  9. Treatment Of Sunitinib-Induced Hypertension In Solid Tumors By Nitric Oxid Donors

    Directory of Open Access Journals (Sweden)

    Luís A. Leon

    2015-08-01

    Hypertension (HT is one of the most common adverse effects of angiogenesis inhibitors. Hypertension observed in clinical trials appears to correlate with the potency of VEGF kinase inhibitor against VEGFR-2: agents with higher potency are associated with a higher incidence of hypertension. Although the exact mechanism by TKIs induce hypertension has not yet been completely clarified, two key hypotheses have been postulated. First, some studies have pointed to a VEGF inhibitors-induced decrease in nitric oxide synthase (NOS and nitric oxide (NO production, that can result in vasoconstriction and increased blood pressure. VEGF, mediated by PI3K/Akt and MAPK pathway, upregulates the endothelial nitric oxide synthase enzyme leading to up-regulation of NO production. So inhibition of signaling through the VEGF pathway would lead to a decrease in NO production, resulting in an increase in vascular resistance and blood pressure. Secondly a decrease in the number of microvascular endothelial cells and subsequent depletion of normal microvessel density (rarefaction occurs upon VEGF signaling inhibition.

  10. Glutamate-induced production of nitric oxide in guinea pig vestibular sensory cells.

    Science.gov (United States)

    Takumida, M; Anniko, M

    2000-06-01

    Glutamate-induced production of nitric oxide (NO) in the vestibular organ of the guinea pig was investigated using the new fluorescence indicator, DAF-2DA, for direct detection of NO. Utricular maculae and isolated vestibular sensory cells were examined to locate NO production sites. The fluorescence intensity of the sensory cells was augmented by stimulation with glutamate, NMDA and AMPA. This is the first direct evidence of NO production in the vestibular end organs. NO may play an important role in the glutamate-induced ototoxicity and also be involved in disease of the inner ear.

  11. Methylglyoxal Induces Mitochondrial Dysfunction and Cell Death in Liver

    OpenAIRE

    Seo, Kyuhwa; Ki, Sung Hwan; Shin, Sang Mi

    2014-01-01

    Degradation of glucose is aberrantly increased in hyperglycemia, which causes various harmful effects on the liver. Methylglyoxal is produced during glucose degradation and the levels of methylglyoxal are increased in diabetes patients. In this study we investigated whether methylglyoxal induces mitochondrial impairment and apoptosis in HepG2 cells and induces liver toxicity in vivo. Methylglyoxal caused apoptotic cell death in HepG2 cells. Moreover, methylglyoxal significantly promoted the p...

  12. CHIP facilitates ubiquitination of inducible nitric oxide synthase and promotes its proteasomal degradation.

    Science.gov (United States)

    Chen, Li; Kong, Xiuqin; Fu, Jin; Xu, Yimiao; Fang, Shuping; Hua, Peng; Luo, Lan; Yin, Zhimin

    2009-01-01

    Inducible nitric oxide synthase (iNOS) is responsible for nitric oxide (NO) synthesis from l-arginine in response to inflammatory mediators. It is reported that iNOS is degraded mainly by the ubiquitin-proteasome pathway in RAW264.7 cells and human embryonic kidney (HEK) 293 cells. In this study, we showed that iNOS was ubiquitinated and degraded dependent on CHIP (COOH terminus of heat shock protein 70-interacting protein), a chaperone-dependent ubiquitin ligase. The results from overexpression and RNAi experiments demonstrated that CHIP decreased the protein level of iNOS, shortened the half-life of iNOS and attenuated the production of NO. Furthermore, CHIP promoted ubiquitination and proteasomal degradation of iNOS by associating with iNOS. These results suggest that CHIP plays an important role in regulation iNOS activity.

  13. HEAVY METALS INDUCE APOPTOSIS IN LIVER OF MICE

    Directory of Open Access Journals (Sweden)

    Khalid H. Gathwan

    2012-05-01

    Full Text Available Cadmium (C d and zinc (Zn are an industrial and environmental pollutant of aquatic system has attracted the attention of research's all over the world. In the present study the toxic effects of zinc (Zn and Cadmium (C d on the liver of male mice. Male Balb /c mice weighing 32-34 gm, 70 days old, were treated orally with (1-10 mg/kg body wt. CdCl2 and 1-8 mg/kg body wt. ZnCl2. The body weight, liver weight, histological examination of liver, along with DNA ladder for apoptosis was studied. Cadmium and zinc induced both a time, and dose dependent increase in apoptotic, severity of necrosis. Liver weight, body weight decreased with increase of dose. It has been concluded that cadmium and zinc caused necrotic effect in liver and apoptotic as well as decrease body weight and liver weight.

  14. Artificial liver support in pigs with acetaminophen-induced acute liver failure

    Science.gov (United States)

    He, Guo-Lin; Feng, Lei; Cai, Lei; Zhou, Chen-Jie; Cheng, Yuan; Jiang, Ze-Sheng; Pan, Ming-Xin; Gao, Yi

    2017-01-01

    AIM To establish a reversible porcine model of acute liver failure (ALF) and treat it with an artificial liver system. METHODS Sixteen pigs weighing 30-35 kg were chosen and administered with acetaminophen (APAP) to induce ALF. ALF pigs were then randomly assigned to either an experimental group (n = 11), in which a treatment procedure was performed, or a control group (n = 5). Treatment was started 20 h after APAP administration and continued for 8 h. Clinical manifestations of all animals, including liver and kidney functions, serum biochemical parameters and survival times were analyzed. RESULTS Twenty hours after APAP administration, the levels of serum aspartate aminotransferase, total bilirubin, creatinine and ammonia were significantly increased, while albumin levels were decreased (P < 0.05). Prothrombin time was found to be extended with progression of ALF. After continuous treatment for 8 h (at 28 h), aspartate aminotransferase, total bilirubin, creatinine, and ammonia showed a decrease in comparison with the control group (P < 0.05). A cross-section of livers revealed signs of vacuolar degeneration, nuclear fragmentation and dissolution. Concerning survival, porcine models in the treatment group survived for longer times with artificial liver system treatment (P < 0.05). CONCLUSION This model is reproducible and allows for quantitative evaluation of new liver systems, such as a bioartificial liver. The artificial liver system (ZHJ-3) is safe and effective for the APAP-induced porcine ALF model. PMID:28566885

  15. Prostaglandin E2 potentiates interferon-γ-induced nitric oxide production in cultured rat microglia.

    Science.gov (United States)

    Nagano, Takayuki; Nishiyama, Ryo; Sanada, Ayaka; Mutaguchi, Yukiko; Ioku, Anna; Umeki, Hirohisa; Kishimoto, Satoshi; Yamanaka, Daisuke; Kimura, Shinya H; Takemura, Motohiko

    2017-02-01

    Prostaglandin E2 (PGE2 ) plays crucial roles in managing microglial activation through the prostanoid EP2 receptor, a PGE2 receptor subtype. In this study, we report that PGE2 enhances interferon-γ (IFN-γ)-induced nitric oxide production in microglia. IFN-γ increased the release of nitrite, a metabolite of nitric oxide, which was augmented by PGE2 , although PGE2 by itself slightly affects nitrite release. The potentiating effect of PGE2 was positively associated with increased expression of inducible nitric oxide synthase. In contrast to nitrite release induced by IFN-γ, lipopolysaccharide-induced nitrite release was not affected by PGE2 . An EP2 agonist, ONO-AE1-259-01 also augmented IFN-γ-induced nitrite release, while an EP1 agonist, ONO-DI-004, an EP3 agonist, ONO-AE-248, or an EP4 agonist, ONO-AE1-329, did not. In addition, the potentiating effect of PGE2 was inhibited by an EP2 antagonist, PF-04418948, but not by an EP1 antagonist, ONO-8713, an EP3 antagonist, ONO-AE3-240, or an EP4 antagonist, ONO-AE3-208, at 10(-6)  M. Among the EP agonists, ONO-AE1-259-01 alone was able to accumulate cyclic adenosine monophosphate (AMP), and among the EP antagonists, PF-04418948 was the only one able to inhibit PGE2 -increased intracellular cyclic AMP accumulation. On the other hand, IFN-γ promoted phosphorylation of signal transducer and activator of transcription 1, which was not affected by PGE2 . Furthermore, other prostanoid receptor agonists, PGD2 , PGF2α , iloprost, and U-46119, slightly affected IFN-γ-induced nitrite release. These results indicate that PGE2 potentiates IFN-γ-induced nitric oxide production in microglia through the EP2 receptor, which may shed light on one of the pro-inflammatory aspects of PGE2 . © 2016 International Society for Neurochemistry.

  16. Aspirin-Induced Acute Liver Injury

    Science.gov (United States)

    Satoskar, Rohit

    2014-01-01

    Aspirin is thought to be a relatively safe drug in adults. The association of aspirin and Reye syndrome in children is well documented. We report a 41-year-old female with pericarditis who was treated with high-dose aspirin and developed subsequent acute liver injury. After discontinuation of aspirin, liver enzyme elevation and right upper quadrant pain both resolved. We conclude that high-dose aspirin should be considered as a potentially hepatotoxic agent. PMID:26157904

  17. A multiwall carbon nanotubes film-modified carbon fiber ultramicroelectrode for the determination of nitric oxide radical in liver mitochondria.

    Science.gov (United States)

    Wang, Yazhen; Li, Qing; Hu, Shengshui

    2005-02-01

    A novel chemically modified electrode based on the multiwall carbon nanotubes (MWNTs) film-coated carbon fiber ultramicroelectrode (CFUE) has been described for the determination of nitric oxide radical (.NO). The electrochemical behaviors of MWNTs-modified CFUE have been characterized in 0.2 mmol L(-1) K(4)Fe(CN)(6) and 0.1 mol L(-1) KCl solution. The Nafion film was used to avoid some electroactive interferences. The amount of Nafion was optimized, and some possible interferents [such as nitrite (NO(2)(-)), nitrate (NO(3)(-)), ascorbate, dopamine (DA), l-arginine (l-Arg), etc.] were tested and evaluated. The oxidation peak current of .NO increases significantly at the MWNT/Nafion-modified CFUE, in contrast to that at the bare and the Nafion-modified CFUE, and the oxidation peak potential is at 0.78 V (vs. SCE), which can be used for the detection of .NO. The oxidation peak current is linearly with the concentration of .NO from 2x10(-7) to 8.6x10(-5) mol L(-1), and the detection limit is 2x10(-8) mol L(-1). The liver mitochondria in Carassius auratus were isolated and .NO release from mitochondria was monitored by using this ultramicroelectrode system.

  18. The Role of Photolabile Dermal Nitric Oxide Derivates in Ultraviolet Radiation (UVR-Induced Cell Death

    Directory of Open Access Journals (Sweden)

    Christoph V. Suschek

    2012-12-01

    Full Text Available Human skin is exposed to solar ultraviolet radiation comprising UVB (280–315 nm and UVA (315–400 nm on a daily basis. Within the last two decades, the molecular and cellular response to UVA/UVB and the possible effects on human health have been investigated extensively. It is generally accepted that the mutagenic and carcinogenic properties of UVB is due to the direct interaction with DNA. On the other hand, by interaction with non-DNA chromophores as endogenous photosensitizers, UVA induces formation of reactive oxygen species (ROS, which play a pivotal role as mediators of UVA-induced injuries in human skin. This review gives a short overview about relevant findings concerning the molecular mechanisms underlying UVA/UVB-induced cell death. Furthermore, we will highlight the potential role of cutaneous antioxidants and photolabile nitric oxide derivates (NODs in skin physiology. UVA-induced decomposition of the NODs, like nitrite, leads not only to non-enzymatic formation of nitric oxide (NO, but also to toxic reactive nitrogen species (RNS, like peroxynitrite. Whereas under antioxidative conditions the generation of protective amounts of NO is favored, under oxidative conditions, less injurious reactive nitrogen species are generated, which may enhance UVA-induced cell death.

  19. A novel organ preservation for small partial liver transplantations in rats: venous systemic oxygen persufflation with nitric oxide gas.

    Science.gov (United States)

    Yagi, S; Nagai, K; Kadaba, P; Afify, M; Teramukai, S; Uemoto, S; Tolba, R H

    2013-01-01

    The prognosis for recipients of small liver grafts is poor. The aim of this study was to determine the impact of venous systemic oxygen persufflation (VSOP) with nitric oxide (NO) gas for 30% partial liver preservation and transplantation in rats. After we determined optimal NO concentration as 40 ppm in vitro with the isolated perfused rat liver model, we assessed liver injury and regeneration in vivo at 1, 3, 24 and 168 h after transplantation in the following three groups after 3 h-cold storage (n = 20 per group): control group = static storage; VSOP group = oxygen persufflation and VSOP+NO group = oxygen with NO persufflation. The liver graft persufflation was achieved with medical gas via the suprahepatic vena cava; In comparison with control group after transplantation, VSOP+NO preservation (1) increased portal circulation, (2) reduced AST and ALT release, (3) upregulated hepatic endothelial NO synthase, (4) reduced hepatocyte and bileductule damage and (5) improved liver regeneration. These results suggest that gaseous oxygen with NO persufflation is a novel and safe preservation method for small partial liver grafts, not only alleviating graft injury but also improve liver regeneration after transplantation. © Copyright 2012 The American Society of Transplantation and the American Society of Transplant Surgeons.

  20. Burn injury induces histopathological changes and cellproliferation in liver of rats

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    AIM To investigate effects of severe burn injury (BI) inrat liver through the histopathological and inflammatorymarkers analysis.METHODS: Forty-two male Wistar rats were distributedinto two groups, control (C) and subjected to scaldBI (SBI). The animals were euthanized one, four and14 d post sham or 45% of the total body surface BI.Liver fragments were submitted to histopathological,morphoquantitative (hepatocyte area and cell density),ciclooxigenase-2 (COX-2) immunoexpression, and geneexpression [real-time polymerase chain reaction fortumor necrosis factor (TNF)-α, inducible nitric oxidesynthase (iNOS) and caspase-3] methods.RESULTS: Histopathological findings showed inflammatoryprocess in all periods investigated and hepatocytedegeneration added to increased amount of connectivetissue 14 d post injury. Hepatocyte area, the density ofbinucleated hepatocytes and density of sinusoidal cellsof SBI groups were increased when compared withcontrol. COX-2 immunoexpression was stronger in SBIgroups. No differences were found in TNF-α, iNOS andcaspase-3 gene expression.CONCLUSION: BI induces histopathological changes,upregulation of COX-2 immunoexpression, and cellproliferation in liver of rats.

  1. Nitric oxide stress in sporadic inclusion body myositis muscle fibres: inhibition of inducible nitric oxide synthase prevents interleukin-1β-induced accumulation of β-amyloid and cell death.

    Science.gov (United States)

    Schmidt, Jens; Barthel, Konstanze; Zschüntzsch, Jana; Muth, Ingrid E; Swindle, Emily J; Hombach, Anja; Sehmisch, Stephan; Wrede, Arne; Lühder, Fred; Gold, Ralf; Dalakas, Marinos C

    2012-04-01

    Sporadic inclusion body myositis is a severely disabling myopathy. The design of effective treatment strategies is hampered by insufficient understanding of the complex disease pathology. Particularly, the nature of interrelationships between inflammatory and degenerative pathomechanisms in sporadic inclusion body myositis has remained elusive. In Alzheimer's dementia, accumulation of β-amyloid has been shown to be associated with upregulation of nitric oxide. Using quantitative polymerase chain reaction, an overexpression of inducible nitric oxide synthase was observed in five out of ten patients with sporadic inclusion body myositis, two of eleven with dermatomyositis, three of eight with polymyositis, two of nine with muscular dystrophy and two of ten non-myopathic controls. Immunohistochemistry confirmed protein expression of inducible nitric oxide synthase and demonstrated intracellular nitration of tyrosine, an indicator for intra-fibre production of nitric oxide, in sporadic inclusion body myositis muscle samples, but much less in dermatomyositis or polymyositis, hardly in dystrophic muscle and not in non-myopathic controls. Using fluorescent double-labelling immunohistochemistry, a significant co-localization was observed in sporadic inclusion body myositis muscle between β-amyloid, thioflavine-S and nitrotyrosine. In primary cultures of human myotubes and in myoblasts, exposure to interleukin-1β in combination with interferon-γ induced a robust upregulation of inducible nitric oxide synthase messenger RNA. Using fluorescent detectors of reactive oxygen species and nitric oxide, dichlorofluorescein and diaminofluorescein, respectively, flow cytometry revealed that interleukin-1β combined with interferon-γ induced intracellular production of nitric oxide, which was associated with necrotic cell death in muscle cells. Intracellular nitration of tyrosine was noted, which partly co-localized with amyloid precursor protein, but not with desmin

  2. Role of nitric oxide in adenosine-induced vasodilation in humans

    Science.gov (United States)

    Costa, F.; Biaggioni, I.; Robertson, D. (Principal Investigator)

    1998-01-01

    Vasodilation is one of the most prominent effects of adenosine and one of the first to be recognized, but its mechanism of action is not completely understood. In particular, there is conflicting information about the potential contribution of endothelial factors. The purpose of this study was to explore the role of nitric oxide in the vasodilatory effect of adenosine. Forearm blood flow responses to intrabrachial adenosine infusion (125 microg/min) were assessed with venous occlusion plethysmography during intrabrachial infusion of saline or the nitric oxide synthase inhibitor NG-monomethyl-L-arginine (L-NMMA) (12.5 mg/min). Intrabrachial infusions of acetylcholine (50 microg/min) and nitroprusside (3 microg/min) were used as a positive and negative control, respectively. These doses were chosen to produce comparable levels of vasodilation. In a separate study, a second saline infusion was administered instead of L-NMMA to rule out time-related effects. As expected, pretreatment with L-NMMA reduced acetylcholine-induced vasodilation; 50 microg/min acetylcholine increased forearm blood flow by 150+/-43% and 51+/-12% during saline and L-NMMA infusion, respectively (Pvasodilation is not mediated by nitric oxide in the human forearm.

  3. Simvastatin Attenuates Contrast-Induced Nephropathy through Modulation of Oxidative Stress, Proinflammatory Myeloperoxidase, and Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Ketab E. Al-Otaibi

    2012-01-01

    Full Text Available Contrast media- (CM- induced nephropathy is a serious complication of radiodiagnostic procedures. Available data suggests that the development of prophylaxis strategies is limited by poor understanding of pathophysiology of CM-induced nephropathy. Present study was designed to determine the role of oxidative stress, myeloperoxidase, and nitric oxide in the pathogenesis of iohexol model of nephropathy and its modification with simvastatin (SSTN. Adult Sprague Dawley rats were divided into seven groups. After 24 h of water deprivation, all the rats except in control and SSTN-only groups were injected (10 ml/kg with 25% glycerol. After 30 min, SSTN (15, 30, and 60 mg/kg was administered orally, daily for 4 days. Twenty-four hours after the glycerol injection, iohexol was infused (8 ml/kg through femoral vein over a period of 2 min. All the animals were sacrificed on day 5 and blood and kidneys were collected for biochemical and histological studies. The results showed that SSTN dose dependently attenuated CM-induced rise of creatinine, urea, and structural abnormalities suggesting its nephroprotective effect. A significant increase in oxidative stress (increased lipid hydroperoxides and reduced glutathione levels and myeloperoxidase (MPO and decreased nitric oxide in CM group were reversed by SSTN. These findings support the use of SSTN to combat CM-induced nephrotoxicity.

  4. Nitric oxide mediates alginate oligosaccharides-induced root development in wheat (Triticum aestivum L.).

    Science.gov (United States)

    Zhang, Yunhong; Liu, Hang; Yin, Heng; Wang, Wenxia; Zhao, Xiaoming; Du, Yuguang

    2013-10-01

    Alginate oligosaccharides (AOS), which are marine oligosaccharides, are involved in regulating plant root growth, but the promotion mechanism for AOS remains unclear. Here, AOS (10-80 mg L(-1)) were found to induce the generation of nitric oxide (NO) in the root system of wheat (Triticum aestivum L.), which promoted the formation and elongation of wheat roots in a dose-dependent manner. NO inhibitors suggested that nitrate reductase (NR), rather than nitric oxide synthase (NOS), was essential for AOS-induced root development. Further studies confirmed that AOS-induced NO generation in wheat roots by up-regulating the gene expression and enzyme activity of NR at the post-transcriptional level. The anatomy and RT-PCR results showed that AOS accelerated the division and growth of stele cells, leading to an increase in the ratio of stele area to root transverse area. This could be inhibited by the NR inhibitor, sodium tungstate, which indicated that NO catalyzed by the NR was involved in AOS regulation of root development. Taken together, in the early stage of AOS-induced root development, NO generation was a novel mechanism by which AOS regulated plant growth. The results also showed that this marine resource could be widely used for crop development.

  5. Role of IRAK-M in alcohol induced liver injury.

    Directory of Open Access Journals (Sweden)

    Yipeng Wang

    Full Text Available Increasing evidence suggests that innate immunity plays an important role in alcohol-induced liver injury and most studies have focused on positive regulation of innate immunity. The main objective of this study was to investigate the negative regulator of innate immunity, IL-1/Toll-like receptor (TLR signaling pathways and interleukin receptor-associated kinase-M (IRAK-M in alcoholic liver injury. We established an alcohol-induced liver injury model using wild type and IRAK-M deficient B6 mice and investigated the possible mechanisms. We found that in the absence of IRAK-M, liver damage by alcohol was worse with higher alanine transaminase (ALT, more immune cell infiltration and increased numbers of IFNγ producing cells. We also found enhanced phagocytic activity in CD68(+ cells. Moreover, our results revealed altered gut bacteria after alcohol consumption and this was more striking in the absence of IRAK-M. Our study provides evidence that IRAK-M plays an important role in alcohol-induced liver injury and IRAK-M negatively regulates the innate and possibly the adaptive immune response in the liver reacting to acute insult by alcohol. In the absence of IRAK-M, the hosts developed worse liver injury, enhanced gut permeability and altered gut microbiota.

  6. Drug induced liver injury: do we still need a routine liver biopsy for diagnosis today?

    Science.gov (United States)

    Teschke, Rolf; Frenzel, Christian

    For the pathologist, the diagnosis of drug induced liver injury (DILI) is challenging, because histopathological features mimic all primary hepatic and biliary diseases, lacking changes that are specific for DILI. Therefore, in any patient of suspected DILI who underwent liver biopsy, the pathologist will assure the clinician that the observed hepatic changes are compatible with DILI, but this information is less helpful due to lack of specificity. Rather, the pathologist should assess liver biopsies blindly, without knowledge of prior treatment by drugs. This will result in a detailed description of the histological findings, associated with suggestions for potential causes of these hepatic changes. Then, it is up to the physician to reassess carefully the differential diagnoses, if not done before. At present, liver histology is of little impact establishing the diagnosis of DILI with the required degree of certainty, and this shortcoming also applies to herb induced liver injury (HILI). To reach at the correct diagnoses of DILI and HILI, clinical and structured causality assessments are therefore better approaches than liver histology results obtained through liver biopsy, an invasive procedure with a low complication rate.

  7. Advances in Engineered Liver Models for Investigating Drug-Induced Liver Injury

    Science.gov (United States)

    Lin, Christine

    2016-01-01

    Drug-induced liver injury (DILI) is a major cause of drug attrition. Testing drugs on human liver models is essential to mitigate the risk of clinical DILI since animal studies do not always suffice due to species-specific differences in liver pathways. While primary human hepatocytes (PHHs) can be cultured on extracellular matrix proteins, a rapid decline in functions leads to low sensitivity (<50%) in DILI prediction. Semiconductor-driven engineering tools now allow precise control over the hepatocyte microenvironment to enhance and stabilize phenotypic functions. The latest platforms coculture PHHs with stromal cells to achieve hepatic stability and enable crosstalk between the various liver cell types towards capturing complex cellular mechanisms in DILI. The recent introduction of induced pluripotent stem cell-derived human hepatocyte-like cells can potentially allow a better understanding of interindividual differences in idiosyncratic DILI. Liver models are also being coupled to other tissue models via microfluidic perfusion to study the intertissue crosstalk upon drug exposure as in a live organism. Here, we review the major advances being made in the engineering of liver models and readouts as they pertain to DILI investigations. We anticipate that engineered human liver models will reduce drug attrition, animal usage, and cases of DILI in humans. PMID:27725933

  8. Optimal Timing for Venous Systemic Oxygen Persufflation Supplemented with Nitric Oxide Gas in Cold-Stored, Warm Ischemia-Damaged Experimental Liver Grafts.

    Science.gov (United States)

    Porschen, Anne; Kadaba Srinivasan, Pramod; Iwasaki, Junji; Afify, Mamdouh; Tolba, René H

    2016-01-01

    Worldwide shortage of donor organs has increased the use of donation after cardiac death (DCD). The aim of this study was to analyze the best time point for venous systemic oxygen persufflation (VSOP) supplemented with nitric oxide (NO) gas during the 1st and 24th hour of cold storage (CS) in warm ischemia (WI)-damaged experimental liver grafts. Liver grafts (n = 5) were retrieved after 30 min of WI induced by cardiac arrest and CS in histidine-tryptophan-ketoglutarate solution at 4°C. The 1st hour group was immediately persufflated with a VSOP plus NO (VSOP+NO) mixture for 1 h followed by 23 h of static CS (DCD+NO 1st hour). The 24th hour group entailed CS for 23 h followed by 1 h of VSOP+NO persufflation (DCD+NO 24th hour). CS livers without WI but with VSOP served as controls. CS livers with WI represented the fourth group (DCD). Viability of the liver grafts was assessed by normothermic isolated reperfusion for 45 min with oxygenated Krebs-Henseleit buffer. Data are presented as mean ± SEM (control vs. DCD vs. DCD+NO 1st hour vs. DCD+NO 24th hour). After 45 min of reperfusion, the DCD+NO 1st hour group showed significantly lower aspartate aminotransferase (13.4 ± 5.3, 63.2 ± 17.3, 25.6 ± 3.9, and 82.8 ± 27.3 U/l) and lactate dehydrogenase levels (289.4 ± 41.2, 2,139.4 ± 542.7, 577.2 ± 117.2, and 2,429 ± 221.6 U/l). Malondialdehyde levels were significantly abrogated (1.0 ± 0.3, 2.7 ± 1, 1.0 ± 0, and 3.9 ± 1.2 nmol/ml). Significantly higher levels of portal venous pressure were recorded in the DCD+NO 24th hour group (12.0 ± 1, 21.2 ± 3.1, 16.1 ± 1, and 23.2 ± 3.5 mm Hg). NO levels were recorded after 5 min of reperfusion (1.42 ± 0.17, 1.8 ± 0.2, 2.7 ± 0.2, and 2.6 ± 0.1 μmol/l). Bile production levels showed no statistical significance (23.2 ± 3.8, 27.3 ± 1.8, 43.5 ± 18, and 31 ± 2.5 μl/45 min). Our results present the beneficial effects of NO combined with VSOP during the 1st hour of CS of WI-damaged experimental liver grafts.

  9. Enhancement of fracture healing in the rat, modulated by compounds that stimulate inducible nitric oxide synthase

    Science.gov (United States)

    Rajfer, R. A.; Kilic, A.; Neviaser, A. S.; Schulte, L. M.; Hlaing, S. M.; Landeros, J.; Ferrini, M. G.; Ebramzadeh, E.

    2017-01-01

    Objectives We investigated the effects on fracture healing of two up-regulators of inducible nitric oxide synthase (iNOS) in a rat model of an open femoral osteotomy: tadalafil, a phosphodiesterase inhibitor, and the recently reported nutraceutical, COMB-4 (consisting of L-citrulline, Paullinia cupana, ginger and muira puama), given orally for either 14 or 42 days. Materials and Methods Unilateral femoral osteotomies were created in 58 male rats and fixed with an intramedullary compression nail. Rats were treated daily either with vehicle, tadalafil or COMB-4. Biomechanical testing of the healed fracture was performed on day 42. The volume, mineral content and bone density of the callus were measured by quantitative CT on days 14 and 42. Expression of iNOS was measured by immunohistochemistry. Results When compared with the control group, the COMB-4 group exhibited 46% higher maximum strength (t-test, p = 0.029) and 92% higher stiffness (t-test, p = 0.023), but no significant changes were observed in the tadalafil group. At days 14 and 42, there was no significant difference between the three groups with respect to callus volume, mineral content and bone density. Expression of iNOS at day 14 was significantly higher in the COMB-4 group which, as expected, had returned to baseline levels at day 42. Conclusion This study demonstrates an enhancement in fracture healing by an oral natural product known to augment iNOS expression. Cite this article: R. A. Rajfer, A. Kilic, A. S. Neviaser, L. M. Schulte, S. M. Hlaing, J. Landeros, M. G. Ferrini, E. Ebramzadeh, S-H. Park. Enhancement of fracture healing in the rat, modulated by compounds that stimulate inducible nitric oxide synthase: Acceleration of fracture healing via inducible nitric oxide synthase. Bone Joint Res 2017:6:–97. DOI: 10.1302/2046-3758.62.BJR-2016-0164.R2. PMID:28188129

  10. Protective effect of inducible nitric oxide synthase inhibitor on pancreas transplantation in rats

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To investigate the effect of inducible nitric oxide synthase inhibitor, aminoguanidine, on pancreas transplantation in rats.METHODS: A model of pancreas transplantation was established in rats. Streptozotocin-induced diabetic male Wistar rats were randomly assigned to sham-operation control group (n = 6), transplant control group (n=6), and aminoguanidine (AG) treatment group (n=18). In the AG group, aminoguanidine was added to intravascular infusion as the onset of reperfusion at the dose of 60 mg/kg, 80 mg/kg, 100 mg/kg body weight,respectively. Serum nitric oxide (NO) level, blood sugar and amylase activity were detected. Nitric oxide synthase (NOS) test kit was used to detect the pancreas cNOS and inducible NOS (iNOS) activity. Pancreas sections stained with HE and immunohistochemistry were evaluated under a light microscope.RESULTS: As compared with the transplant control group, the serum NO level and amylase activity decreased obviously and the evidence for pancreas injury was much less in the AG group. The AG (80 mg/kg body weight) group showed the most significant difference in NO and amylase (NO: 66.0 ± 16.6 vs 192.3 ± 60.0, P <0.01 and amylase: 1426 ± 177 vs 4477 ± 630, P<0.01).The expression and activity of tissue iNOS, and blood sugar in the AG (80 mg/kg body weight) group were much lower than those in the transplant control group (iNOS: 2.01 ± 0.23 vs 26.59 ± 5.78, P < 0.01 and blood sugar: 14.2 ± 0.9 vs 16.8 ± 1.1, P < 0.01).CONCLUSION: Selective iNOS inhibitor, aminoguanidine as a free radical, has a protective effect on pancreas transplantation in rats by inhibiting NO and reducing its toxicity.

  11. Prolonged local forearm hyperinsulinemia induces sustained enhancement of nitric oxide-dependent vasodilation in healthy subjects

    DEFF Research Database (Denmark)

    Hermann, Thomas S; Ihlemann, Nikolaj; Dominguez, Helena;

    2005-01-01

    -dependent and -independent vasodilation.N(G)-monomethyl-L-arginine (L-NMMA) was coinfused to test the degree of nitric oxide (NO)-mediated vasodilation. Insulin infusion for 60 min enhanced serotonin-induced vasodilation by 37% compared to vehicle, p = .016. This increase was maintained for 4 h and was blocked by L......-NMMA. The SNP response was increased by insulin but the increment was inhibited by L-NMMA. Four hours of local forearm hyperinsulinemia causes a sustained increase in endothelium dependent vasodilation in resistance vessels, which is mediated by NO....

  12. Neuronal nitric oxide synthase contributes to pentylenetetrazole-kindling-induced hippocampal neurogenesis.

    Science.gov (United States)

    Zhu, Xinjian; Dong, Jingde; Shen, Kai; Bai, Ying; Chao, Jie; Yao, Honghong

    2016-03-01

    Neuronal nitric oxide synthase (nNOS), the major nitric oxide synthase isoform in the mammalian brain, is implicated in the pathophysiology of several neurological conditions, including epilepsy. Neurogenesis in hippocampal dentate gyrus (DG) persists throughout life in the adult brain. Alterations in this process occur in many neurological diseases, including epilepsy. Few studies, however, have addressed the role of nNOS in hippocampal DG neurogenesis in epileptic brain. The present study, therefore, investigated the role of nNOS in pentylenetetrazole (PTZ)-kindling-induced neurogenesis in hippocampal DG. Our results showed that nNOS expression and enzymatic activity were significantly increased in the hippocampus of PTZ-kindled mice. Meanwhile, these PTZ-kindled mice were characterized by significant enhancement of new born cells proliferation and survival in hippocampal DG, and these survived cells are co-labeled with NeuN and GFAP. Selective inhibition of nNOS by 7-NI, however, suppressed PTZ-kindling-induced hippocampal DG new born cells proliferation and survival, suggesting that nNOS contributes to PTZ-kindling-induced hippocampal neurogenesis.

  13. TRPV1 and TRPA1 mediate peripheral nitric oxide-induced nociception in mice.

    Directory of Open Access Journals (Sweden)

    Takashi Miyamoto

    Full Text Available Nitric oxide (NO can induce acute pain in humans and plays an important role in pain sensitization caused by inflammation and injury in animal models. There is evidence that NO acts both in the central nervous system via a cyclic GMP pathway and in the periphery on sensory neurons through unknown mechanisms. It has recently been suggested that TRPV1 and TRPA1, two polymodal ion channels that sense noxious stimuli impinging on peripheral nociceptors, are activated by NO in heterologous systems. Here, we investigate the relevance of this activation. We demonstrate that NO donors directly activate TRPV1 and TRPA1 in isolated inside-out patch recordings. Cultured primary sensory neurons display both TRPV1- and TRPA1-dependent responses to NO donors. BH4, an essential co-factor for NO production, causes activation of a subset of DRG neurons as assayed by calcium imaging, and this activation is at least partly dependent on nitric oxide synthase activity. We show that BH4-induced calcium influx is ablated in DRG neurons from TRPA1/TRPV1 double knockout mice, suggesting that production of endogenous levels of NO can activate these ion channels. In behavioral assays, peripheral NO-induced nociception is compromised when TRPV1 and TRPA1 are both ablated. These results provide genetic evidence that the peripheral nociceptive action of NO is mediated by both TRPV1 and TRPA1.

  14. Linkage of the human inducible nitric oxide synthase gene to type 1 diabetes.

    Science.gov (United States)

    Johannesen, J; Pie, A; Pociot, F; Kristiansen, O P; Karlsen, A E; Nerup, J

    2001-06-01

    Exposure of human pancreatic islets to a mixture of cytokines induces expression of the inducible nitric oxide synthase (iNOS), impairs beta-cell function, and induces apoptosis. We performed a mutational scanning of all 27 exons of the human NOS2 gene and linkage transmission disequilibrium testing of identified NOS2 polymorphisms in a Danish nationwide type 1 diabetes mellitus (IDDM) family collection. Mutational screening was performed using PCR-amplified exons, followed by single stranded conformation polymorphism and verification of potential polymorphisms by sequencing. The transmission disequilibrium test was performed in an IDDM family material comprising 257 Danish families; 154 families were affected sibling pair families, and 103 families were simplex families. In total, 10 polymorphisms were identified in 8 exons, of which 4 were tested in the family material. A C/T single nucleotide polymorphism in exon 16 resulting in an amino acid substitution, Ser(608)Leu, showed linkage to IDDM in human leukocyte antigen DR3/4-positive affected offspring (P = 0.008; corrected P = 0.024). No other distorted transmission patterns were found for any other tested single nucleotide polymorphism or constructed haplotypes with the exception of those including data from exon 16. In conclusion, linkage of the human NOS2 gene to IDDM in a subset of patients supports a pathogenic role of nitric oxide in human IDDM.

  15. Inflammatory cytokines promote inducible nitric oxide synthase-mediated DNA damage in hamster gallbladder epithelial cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To investigate the link between chronic biliary inflammation and carcinogenesis using hamster gallbladder epithelial cells.METHODS: Gallbladder epithelial cells were isolated from hamsters and cultured with a mixture of inflammatory cytokines including interleukin-1β, interferon-γ, and tumor necrosis factor-α. Inducible nitric oxide synthase (iNOS) expression, nitric oxide (NO) generation, and DNA damage were evaluated.RESULTS: NO generation was increased significantly following cytokine stimulation, and suppressed by an iNOS inhibitor. iNOS mRNA expression was demonstrated in the gallbladder epithelial cells during exposure to inflammatory cytokines. Furthermore, NO-dependent DNA damage, estimated by the comet assay, was significantly increased by cytokines, and decreased to control levels by an iNOS inhibitor.CONCLUSION: Cytokine stimulation induced iNOS expression and NO generation in normal hamster gallbladder epithelial cells, which was sufficient to cause DNA damage. These results indicate that NO-mediated genotoxicity induced by inflammatory cytokines through activation of iNOS may be involved in the process of biliary carcinogenesis in response to chronic inflammation of the biliary tree.

  16. Hepatoprotective role of ganoderma lucidum polysaccharide against BCG-induced immune liver injury in mice

    Institute of Scientific and Technical Information of China (English)

    Guo-Liang Zhang; Ye-Hong Wang; Wei Ni; Hui-Ling Teng; Zhi-Bin Lin

    2002-01-01

    AIM: To examine the effect of ganoderma lucidumpolysaccharide (GLP) on the immune liver injuryinduced by BCG infection, and investigate therelationship between degrees of hepatic damage andNO production in mice.METHODS: Immune hepatic injury was markedlyinduced by BCG-pretreatment (125 mg.kg-1, 2-week, iv)or by BCG-pretreatment plus lipopolysaccharide (LPS,125 μg.kg-1, 12-hour, iv) in mice in vivo.Hepatocellulardamage induced by BCG-pretreated plus inflammatorycytokines mixture (CM), which was included TNF-α, IL1β, IFN-γ and LPS in culture medium in vitro.Administration of GLP was performed by oral orincubating with culture medium at immune stimulisimultaneity. Liver damage was determined by activityof alanine aminotransferase (ALT) in serum and inhepatocytes cultured supernatant, by liver weightchanges and histopathological examination. NOproduction in the cultured supematant was determinedby the Griess reaction. Moreover, inducible nitric oxidesynthase (iNOS) protein expression was alsoexaminated by immunohistochemi1cal method.RESULTS: Immune hepatic injury was markedly inducedby BCG or BCG plus inflammatory cytokines in BALB/cmice in vivoand in vitro. Under BCG-stimulated condition,augment of the liver weight and increase of the serum/supernatant ALT level were observed, as well asgranuloma forming and inflammatory cells soakage wereobserved by microscopic analysis within liver tissues.Moreover, NO production was also increased by BCG or/and CH stimuli in the culture supernatant, and a lot ofiNOS positive staining was observed in BCG-prestimulated hepatic sections. Application of GLPsignificantly mitigated hepatic tumefaction, decreasedALT enzyme release and NO production in serum/supernatant, improved the pathological changes ofchronic and acute inflammation induced by BCG-stimuliin mice. Moreover, the immunohistochemical resultshowed that GLP inhibited iNOS protein expression inBCG-immune hepatic damage model.CONCLUSION: The present study indicates that

  17. DIETARY ADENINE ALLEVIATES FATTY LIVER INDUCED BY OROTIC ACID

    Directory of Open Access Journals (Sweden)

    Yohanes Buang

    2010-12-01

    Full Text Available The effects of dietary adenine in fatty liver induced by orotic acid (OA were studied. Rats were paired-fed 1% OA-supplemented diets with/or without 0.25% adenine or a diet without OA for 10 days. Serum lipid profiles were measured using enzyme assay kits. Lipids of liver tissues were extracted and liver lipid contents were determined. A peach of liver was prepared to determine the activities of fatty acid synthase (FAS and fatty acid β-oxidation. The results showed that liver TG content of OA-fed rats increased markedly in comparison to basal group.  However, the addition of adenine to the diet reversed promotion of liver TG content to basal level. It was also found that FAS activities decreased. Furthermore, these diets reversed the inhibition of fatty acid β-oxidation to basal level and induced the serum lipid levels secretion. Therefore, the alleviation of fatty liver in OA-treated rats given dietary adenine is associated with the inhibition of FAS activities accompanied with the promotion of mitochondrial fatty acid β-oxidation and the promotion of serum lipid secretion from the hepatic tissue into the bloodstream.

  18. Protective effects of polydatin from Polygonum cuspidatum against carbon tetrachloride-induced liver injury in mice.

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    Hong Zhang

    Full Text Available Polydatin is one of main compounds in Polygonum cuspidatum, a plant with both medicinal and nutritional value. The possible hepatoprotective effects of polydatin on acute liver injury mice induced by carbon tetrachloride (CCl(4 and the mechanisms involved were investigated. Intraperitoneal injection of CCl(4 (50 µl/kg resulted in a significant increase in the levels of serum aspartate aminotransferase (AST, alanine aminotransferase (ALT and hepatic malondialdehyde (MDA, also a marked enhancement in the expression of hepatic tumor necrosis factor-alpha (TNF-α, interleukin-1 beta (IL-1β, cyclooxygenase-2 (COX-2, inducible nitric oxide synthase (iNOS and nuclearfactor-kappa B (NF-κB. On the other hand, decreased glutathione (GSH content and activities of glutathione transferase (GST, superoxide dismutase (SOD, catalase (CAT and glutathione peroxidase (GPx were observed following CCl(4 exposure. Nevertheless, all of these phenotypes were evidently reversed by preadministration of polydatin for 5 continuous days. The mRNA and protein expression levels of hepatic growth factor-beta1 (TGF-β(1 were enhanced further by polydatin. These results suggest that polydatin protects mice against CCl(4-induced liver injury through antioxidant stress and antiinflammatory effects. Polydatin may be an effective hepatoprotective agent and a promising candidate for the treatment of oxidative stress- and inflammation-related diseases.

  19. Ketogenesis prevents diet-induced fatty liver injury and hyperglycemia

    OpenAIRE

    Cotter, David G.; Ercal, Baris; Huang, Xiaojing; Leid, Jamison M.; d’Avignon, D. André; Graham, Mark J.; Dietzen, Dennis J.; Brunt, Elizabeth M; Patti, Gary J.; Crawford, Peter A.

    2014-01-01

    Nonalcoholic fatty liver disease (NAFLD) spectrum disorders affect approximately 1 billion individuals worldwide. However, the drivers of progressive steatohepatitis remain incompletely defined. Ketogenesis can dispose of much of the fat that enters the liver, and dysfunction in this pathway could promote the development of NAFLD. Here, we evaluated mice lacking mitochondrial 3-hydroxymethylglutaryl CoA synthase (HMGCS2) to determine the role of ketogenesis in preventing diet-induced steatohe...

  20. Estrogen reduces CCL4- induced liver fibrosis in rats

    Institute of Scientific and Technical Information of China (English)

    Jun-Wang Xu; Jun Gong; Xin-Ming Chang; Jin-Yan Luo; Lei Dong; Zhi-Ming Hao; Ai Jia; Gui-Ping Xu

    2002-01-01

    AIM: Chronic liver diseases, such as fibrosis or cirrhosis,are more common in men than in women. This genderdifference may be related to the effects of sex hormones onthe liver. The aim of the present work was to investigatethe effects of estrogen on CCL4-induced fibrosis of the liverin rats.METHODS: Liver fibrosis was induced in male, female andovariectomized rats by CCL4 administration. All the groupswere treated with estradiol(1 mg/kg) twice weekly. Andtamoxifen wasgiven to male fibrosis model. At the end of 8weeks, all therats were killed to study serum indicators andthe livers.RESULTS: Estradiol treatment reduced aspartateaminotransferase(AST), alanine aminotransferase (ALT),hyaluronic acid(HA) and type IV collagen(CIV) in sera,suppressed hepatic collagen content, decreased the areas ofhepatic stellate cells (HSC) positive for α-smooth muscle actin(α-SMA), and lowered the synthesis of hepatic type I collagensignificantly in both sexes and ovariectomy fibrotic rats inducedby CCL4 administration. Whereas, tamoxifen had the oppositeeffect. The fibrotic response of the female liver to CCL4treatment was significantly weaker than that of male liver.CONCLUSION: Estradiol reduces CCL4-induced hepaticfibrosis in rats. The antifibrogenic role of estrogen in theliver may be one reason for the sex associated differencesin the progression from hepatic fibrosis to cirrhosis.

  1. Investigation of Homocystein Plasma Level in Cholestatic Rat and Its Effect on Nitric Oxide Secretion in Liver

    Directory of Open Access Journals (Sweden)

    N. Mirazi

    2005-04-01

    Full Text Available Homocystein (Hcy,one of the thio-amino acid is known as a risk factor in some cardiovascular diseases with releasing O2 radical . It has also been reported that; there is oxidative stress effects of Hcy in cholestasis. The aim of this study is to determine plasma Hcy alteration and nitric oxide (NO in liver and its effects on pathologic disfunction.In this study , 150 Spraque – Dawley male rats with 200 ± 20g body weight were used in the experiments and they were randomly divided in three control, SHAM and bile duct ligation (BDL groups (n= 10-12 . In 7th,14th,21st and 28th days cholestasis was observed in BDL group,the animal were anesthetized with ether and then blood samples were taken from heart directly and analysed for cystein , methionine by HPLC and HPLC-UV. Two hours before blood sampling , 40 and 100 mg/kg methionine were injected (I.P .All data are expressed as mean  SEM. Statistical evaluation of data performed by SPSS soft ware using analysis of variance (ANOVA followed by post hoc test. P-values less than 0.05 were considered statistically significant .The results suggest that billirubin and hepatic enzymes were significantly elevated in BDL rats compared with SHAM and controls (P<0.05. Homocystein concentration was significantly rised in 14th day in BDL group (P<0.05. The plasma cystein and methionine level were significantly elevated in BDL rats compared with SHAM and control groups ( p = 0.01 . Plasma nitrate / nitrite ratio were significantly increased in BDL rats compared with SHAM and control rats (P<0.05. With these data we suppose that some of the systemic oxidative stresses in BDL rat model of cholestasis contributes possibly through NO-dependent mechanisms disorders.

  2. Nitric oxide acts as a positive regulator to induce metamorphosis of the ascidian Herdmania momus.

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    Nobuo Ueda

    Full Text Available Marine invertebrates commonly have a biphasic life cycle in which the metamorphic transition from a pelagic larva to a benthic post-larva is mediated by the nitric oxide signalling pathway. Nitric oxide (NO is synthesised by nitric oxide synthase (NOS, which is a client protein of the molecular chaperon heat shock protein 90 (HSP90. It is notable, then, that both NO and HSP90 have been implicated in regulating metamorphosis in marine invertebrates as diverse as urochordates, echinoderms, molluscs, annelids, and crustaceans. Specifically, the suppression of NOS activity by the application of either NOS- or HSP90-inhibiting pharmacological agents has been shown consistently to induce the initiation of metamorphosis, leading to the hypothesis that a negative regulatory role of NO is widely conserved in biphasic life cycles. Further, the induction of metamorphosis by heat-shock has been demonstrated for multiple species. Here, we investigate the regulatory role of NO in induction of metamorphosis of the solitary tropical ascidian, Herdmania momus. By coupling pharmacological treatments with analysis of HmNOS and HmHSP90 gene expression, we present compelling evidence of a positive regulatory role for NO in metamorphosis of this species, in contrast to all existing ascidian data that supports the hypothesis of NO as a conserved negative regulator of metamorphosis. The exposure of competent H. momus larvae to a NOS inhibitor or an NO donor results in an up-regulation of NOS and HSP90 genes. Heat shock of competent larvae induces metamorphosis in a temperature dependent manner, up to a thermal tolerance that approaches 35°C. Both larval/post-larval survival and the appearance of abnormal morphologies in H. momus post-larvae reflect the magnitude of up-regulation of the HSP90 gene in response to heat-shock. The demonstrated role of NO as a positive metamorphic regulator in H. momus suggests the existence of inter-specific adaptations of NO regulation

  3. Liver injury from Herbals and Dietary Supplements in the US Drug Induced Liver Injury Network

    Science.gov (United States)

    Navarro, Victor J.; Barnhart, Huiman; Bonkovsky, Herbert L.; Davern, Timothy; Fontana, Robert J.; Grant, Lafaine; Reddy, K. Rajender; Seeff, Leonard B.; Serrano, Jose; Sherker, Averell H.; Stolz, Andrew; Talwalkar, Jayant; Vega, Maricruz; Vuppalanchi, Raj

    2014-01-01

    Background The Drug-Induced Liver Injury Network (DILIN) studies hepatotoxicity due to conventional medications as well as herbals and dietary supplements (HDS). Rationale To characterize hepatotoxicity and its outcomes from HDS versus medications, patients with hepatotoxicity attributed to medications or HDS were enrolled prospectively between 2004 and 2013. The study took place among eight US referral centers that are part of the DILIN. Consecutive patients with liver injury referred to a DILIN center were eligible. The final sample comprised 130 (15.5%) of all subjects enrolled (839) who were judged to have experienced liver injury due to HDS. Hepatotoxicity due to HDS was evaluated by expert opinion. Demographic and clinical characteristics and outcome assessments including death and liver transplantation were ascertained. Cases were stratified and compared according to the type of agent implicated in liver injury; 45 had injury due to bodybuilding HDS, 85 due to non-bodybuilding HDS, and 709 due to medications. Main Results Liver injury due to HDS increased from 7% to 20% (p Bodybuilding HDS caused prolonged jaundice (median 91 days) in young men but did not result in any fatalities or liver transplantation. The remaining HDS cases presented as hepatocellular injury, predominantly in middle-aged women and more frequently led to death or transplantation compared to injury from medications (13% vs. 3%, p bodybuilding HDS is more severe than from bodybuilding HDS or medications, as evidenced by differences in unfavorable outcomes; death and transplantation. PMID:25043597

  4. Arsenic toxicity induced endothelial dysfunction and dementia: Pharmacological interdiction by histone deacetylase and inducible nitric oxide synthase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Bhupesh, E-mail: drbhupeshresearch@gmail.com; Sharma, P.M.

    2013-11-15

    Arsenic toxicity has been reported to damage all the major organs including the brain and vasculature. Dementia including Alzheimer's disease (AD) and vascular dementia (VaD) are posing greater risk to the world population as it is now increasing at a faster rate. We have investigated the role of sodium butyrate, a selective histone deacetylase (HDAC) inhibitor and aminoguanidine, a selective inducible nitric oxide synthase (iNOS) inhibitor in pharmacological interdiction of arsenic toxicity induced vascular endothelial dysfunction and dementia in rats. Arsenic toxicity was done by administering arsenic drinking water to rats. Morris water-maze (MWM) test was used for assessment of learning and memory. Endothelial function was assessed using student physiograph. Oxidative stress (aortic superoxide anion, serum and brain thiobarbituric acid reactive species, brain glutathione) and nitric oxide levels (serum nitrite/nitrate) were also measured. Arsenic treated rats have shown impairment of endothelial function, learning and memory, reduction in serum nitrite/nitrate and brain GSH levels along with increase in serum and brain TBARS. Sodium butyrate as well as aminoguanidine significantly convalesce arsenic induced impairment of learning, memory, endothelial function, and alterations in various biochemical parameters. It may be concluded that arsenic induces endothelial dysfunction and dementia, whereas, sodium butyrate, a HDAC inhibitor as well as aminoguanidine, a selective iNOS inhibitor may be considered as potential agents for the management of arsenic induced endothelial dysfunction and dementia. - Highlights: • As has induced endothelial dysfunction (Edf) and vascular dementia (VaD). • As has increased oxidative stress, AChE activity and decreased serum NO. • Inhibitors of HDAC and iNOS have attenuated As induced Edf and VaD. • Both the inhibitors have attenuated As induced biochemical changes. • Inhibitor of HDAC and iNOS has shown good potential

  5. Hepatoprotective effects of flavonoids from shekwasha (Citrus depressa) against D-galactosamine-induced liver injury in rats.

    Science.gov (United States)

    Akachi, Toshiyuki; Shiina, Yasuyuki; Ohishi, Yayoi; Kawaguchi, Takumi; Kawagishi, Hirokazu; Morita, Tatsuya; Mori, Makoto; Sugiyama, Kimio

    2010-01-01

    We attempted to isolate the constituent(s) responsible for the suppressive effect of the juice of shekwasha, a citrus produced in Okinawa Prefecture, on D-galactosamine (GalN)-induced liver injury in rats. Liver injury-suppressive activity, as assessed by plasma alanine aminotransferase and aspartate aminotransferase activities, was found only in the fraction that was extracted with n-hexane when three fractions were added to the diet and fed to rats. Of five compounds isolated from the n-hexane-soluble fraction by silica gel column chromatography, three compounds had liver injury-suppressive effects when five compounds were singly force-fed to rats at a level of 300 mg/kg body wt 4 h before the injection with GalN. The structures of the three active compounds were determined as 3',4',5,6,7,8-hexamethoxyflavanone (citromitin), 4',5,6,7,8-pentamethoxyflavone (tangeretin) and 3',4',5,6,7,8-hexamethoxyflavone (nobiletin), which are known flavonoids mainly existing in citrus. Nobiletin, the most important compound in the n-hexane-soluble fraction, also had suppressive effects on liver injuries induced by carbon tetrachloride, acetaminophen and GalN/lipopolysaccharide (LPS) in addition to liver injury induced GalN. Nobiletin suppressed GalN/LPS-induced increases in plasma tumor necrosis factor (TNF)-alpha and nitric oxide (NO) concentrations and hepatic mRNA levels for inducible NO synthase and DNA fragmentation. These results suggest that nobiletin suppressed GalN/LPS-induced liver injury at least by suppressing the production of both TNF-alpha and NO. The results obtained here indicate that the hepatoprotective effect of shekwasha juice is mainly ascribed to several polymethoxy flavonoids included in the juice.

  6. p53 and nitric oxide are involved in cytokine-induced apoptosis in Kasumi-1 and Molt-4 Leukemics cells.

    Science.gov (United States)

    Maharath, Aishath; Fucharoen, Suthat; Tanyong, Dalina I

    2014-06-01

    Immunotherapy has been developed to treat cancers. There are many signaling pathways involved in cytokine induced apoptosis of many cancers but their role remains unclear in some cancers such as leukemia. To investigate the involvement of the nitric oxide (NO) and p53 tumor suppressor gene in apoptotic pathways induced by cytokines in leukemic cell lines. Leukemic cell lines, Kasumi-1 (AML-M2) and Molt- 4 (ALL) were treated with cytokines, interleukin-1β (IL-1β), tumor necrosis factor-α (TNFα), interferon-γ (IFN-γ). The effect of cytokines on the induction cell apoptosis was analysed by flow cytometry. In addition, nitric oxide production and p53 protein levels were measured by using the Griess method and Western blot, respectively. Upon cytokine treatment, there was a significant increase in the percentage of cell apoptosis in both leukemic cell lines. The highest apoptosis was shown in 40 U/ml IFN-γ treated cells. In addition, nitric oxide and p53 protein increased in IFN-γ treated cells. There was a reduction of apoptosis and p53 level after adding the inducible nitric oxide synthase inhibitor, SMT. p53 and nitric oxide are involved in the mediation of apoptosis induced by cytokines in Kasumi-1 and Molt-4 leukemic cell lines.

  7. Liver myofibroblasts up-regulate monocyte CD163 expression via PGE2 during hepatitis B induced liver failure.

    Science.gov (United States)

    Zhang, Min; Ye, Yinong; Wang, Fenglan; Zhu, Jianyun; Zhao, Qiyi; Zheng, Yubao; Gu, Yurong; Xie, Chan; Huang, Zhanlian; Tai, Qiang; Chong, Yutian; Gao, Zhiliang

    2014-03-06

    Although patients with liver failure exhibit a generalized inflammatory-imbalance status, substantial evidence indicates that this immunosuppressive or anti-inflammatory state may be deleterious. Increased expression of CD163 (known to be involved in several anti-inflammatory functions of the immune system) in patients with liver failure is significantly correlated with a fatal outcome. However, little is known of the regulatory mechanisms that influence the expression of CD163. We assessed the expression of CD163 on monocytes from both circulating cells and the liver tissues of patients with hepatitis B induced liver failure using flow cytometry and isolated the myofibroblasts from diseased livers. The ability of human liver myofibroblasts to regulate CD163 expression on monocytes was studied in vitro. We showed that CD163⁺ monocytes were enriched primarily in diseased livers and that they were associated with liver myofibroblasts in the same area. Accordingly, liver myofibroblasts were significantly superior to normal skin fibroblasts in inducing the expression of CD163 on monocytes in vitro. Moreover, we found that liver myofibroblasts triggered the activation of monocytes by secreting PGE2. Inhibition of PGE2 production in liver myofibroblasts using NS-398 markedly reduced CD163 expression in vitro. These results suggest that liver myofibroblasts play a direct role in regulating the expression of CD163 on monocytes in human liver tissues and thereby may regulate monocyte function during hepatitis B induced liver failure.

  8. Trypanosoma congolense Infections: Induced Nitric Oxide Inhibits Parasite Growth In Vivo

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    Wenfa Lu

    2011-01-01

    Full Text Available Wild-type (WT C57BL/6 mice infected intraperitoneally with 5×106 Trypanosoma congolense survive for more than 30 days. C57BL/6 mice deficient in inducible nitric oxide synthase (iNOS−/− and infected with 103 or 5×106 parasites do not control the parasitemia and survive for only 14±7 or 6.8±0.1 days, respectively. Bloodstream trypanosomes of iNOS−/− mice infected with 5×106  T. congolense had a significantly higher ratio of organisms in the S+G2+M phases of the cell cycle than trypanosomes in WT mice. We have reported that IgM anti-VSG-mediated phagocytosis of T. congolense by macrophages inhibits nitric oxide (NO synthesis via CR3 (CD11b/CD18. Here, we show that during the first parasitemia, but not at later stages of infection, T. congolense-infected CD11b−/− mice produce more NO and have a significantly lower parasitemia than infected WT mice. We conclude that induced NO contributes to the control of parasitemia by inhibiting the growth of the trypanosomes.

  9. The Oncogenic Properties Of The Redox Inflammatory Protein Inducible Nitric Oxide Synthase In ER(- Breast Cancer

    Directory of Open Access Journals (Sweden)

    David A. Wink

    2015-08-01

    Full Text Available Inflammation generates reactive chemical species that induce conditions of oxidative nitrosative stress as emerged as factor in poor outcome of many cancers. Our recent findings show that in the inflammatory protein inducible nitric oxide synthase (iNOS is a strong predictor of poor outcome in ER(- patients (Glynn et al. JCI 2010. Furthermore 46 genes, of which 23 were associated with basal like breast cancer, were elevated when iNOS high. In vitro studies using ER(- cell lines showed that fluxes of nitric oxide (NO delivered by NO donors surprising mimic this relationship in the patient cohort. Using this model, we show that NO at different specific concentrations stimulate pro-oncogenic mechanisms such as AKT, ERK, NFkB, AP-1, and HIF-1α that lead to increase of metastatic and cancer stem cells proteins. In addition, we show that tumor suppressor gene BRCA1 and PP2A are inhibited by these NO levels. Similarly other studies show that these concentrations of NO increase immunosuppressive proteins TGF-β and IL-10 in leukocytes to decrease efficacy of some anticancer therapies further contributing to pro-tumorigenic environment. Using this model we have identified several new compounds that have efficacy in xenographic models. These finding have provided a model that shows how NO can affect numerous mechanism that leads to a more aggressive phenotype.

  10. Neuronal and inducible nitric oxide synthase upregulation in the rat medial prefrontal cortex following acute restraint stress: A dataset

    Directory of Open Access Journals (Sweden)

    Jereme G. Spiers

    2016-03-01

    Full Text Available This data article provides additional evidence on gene expression changes in the neuronal and inducible isoforms of nitric oxide synthase in the medial prefrontal cortex following acute stress. Male Wistar rats aged 6–8 weeks were exposed to control or restraint stress conditions for up to four hours in the dark cycle after which the brain was removed and the medial prefrontal cortex isolated by cryodissection. Following RNA extraction and cDNA synthesis, gene expression data were measured using quantitative real-time PCR. The mRNA levels of the neuronal and inducible nitric oxide synthase isoforms, and the inhibitory subunit of NF-κB, I kappa B alpha were determined using the ΔΔCT method relative to control animals. This data article presents complementary results related to the research article entitled ‘Acute restraint stress induces specific changes in nitric oxide production and inflammatory markers in the rat hippocampus and striatum’ [1].

  11. Neuronal and inducible nitric oxide synthase upregulation in the rat medial prefrontal cortex following acute restraint stress: A dataset.

    Science.gov (United States)

    Spiers, Jereme G; Chen, Hsiao-Jou Cortina; Lee, Johnny K; Sernia, Conrad; Lavidis, Nickolas A

    2016-03-01

    This data article provides additional evidence on gene expression changes in the neuronal and inducible isoforms of nitric oxide synthase in the medial prefrontal cortex following acute stress. Male Wistar rats aged 6-8 weeks were exposed to control or restraint stress conditions for up to four hours in the dark cycle after which the brain was removed and the medial prefrontal cortex isolated by cryodissection. Following RNA extraction and cDNA synthesis, gene expression data were measured using quantitative real-time PCR. The mRNA levels of the neuronal and inducible nitric oxide synthase isoforms, and the inhibitory subunit of NF-κB, I kappa B alpha were determined using the ΔΔCT method relative to control animals. This data article presents complementary results related to the research article entitled 'Acute restraint stress induces specific changes in nitric oxide production and inflammatory markers in the rat hippocampus and striatum' [1].

  12. Sestrin2 protects against acetaminophen-induced liver injury.

    Science.gov (United States)

    Kim, Seung Jung; Kim, Kyu Min; Yang, Ji Hye; Cho, Sam Seok; Kim, Ji Young; Park, Su Jung; Lee, Sang Kyu; Ku, Sae Kwang; Cho, Il Je; Ki, Sung Hwan

    2017-05-01

    Acetaminophen (APAP) overdose accounts for half of the cases of acute liver failure worldwide. We previously reported that Sestrin2 (Sesn2) protects against d-galactosamine/lipopolysaccharide-induced acute fulminant liver failure. In this study, we demonstrated that Sesn2 protects APAP-induced liver injury in mice, using a recombinant adenovirus encoding Sesn2 (Ad-Sesn2). First, we found that treatment of mice with toxic levels of APAP significantly reduced Sesn2 expression. Tail-vein injection with Ad-Sesn2 inhibited APAP-induced serum alanine aminotransferase and aspartate aminotransferase levels and markedly reduced hepatocyte degeneration and inflammatory cell infiltration. Additionally, APAP-induced glutathione depletion and reactive oxygen species generation were inhibited by Ad-Sesn2 treatment. Consistently, hepatic inflammatory gene expression and proinflammatory cytokine levels were also inhibited in Sesn2-infected mice, and we observed reduced APAP-mediated apoptotic signaling by terminal transferase-mediated dUTP nick-end labeling staining of the hepatic tissue. At a high dose of APAP, the mortality rate of Ad-Sesn2-infected mice was significantly lower than that of control mice. Furthermore, Sesn2 prevented APAP-induced damage through suppression of downstream mitogen-activated protein kinase pathway activation. Therefore, Sesn2 exerted a protective effect against APAP-induced acute liver damage by inhibiting oxidative stress and proinflammatory signaling. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Osteopontin protects against hyperoxia-induced lung injury by inhibiting nitric oxide synthases

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiang-feng; LIU Shuang; ZHOU Yu-jie; ZHU Guang-fa; Hussein. D Foda

    2010-01-01

    Background Exposure of adult mice to more than 95% O_2 produces a lethal injury by 72 hours. Nitric oxide synthase (NOS) is thought to contribute to the pathophysiology of murine hyperoxia-induced acute lung injury (ALI). Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages. OPN inhibits inducible nitric oxide synthase (iNOS), which generates large amounts of nitric oxide production. However, the relationship between nitric oxide and endogenous OPN in lung tissue during hyperoxia-induced ALI has not yet been elucidated, thus we examined the role that OPN plays in the hyperoxia-induced lung injury and its relationships with NOS.Methods One hundred and forty-four osteopontin knock-out (KO) mice and their matched wild type background control (WT) were exposed in sealed cages >95% oxygen or room air for 24-72 hours, and the severity of lung injury was assessed; expression of OPN, endothelial nitric oxide synthase (eNOS) and iNOS mRNA in lung tissues at 24,48 and 72 hours of hyperoxia were studied by reverse transcription-polymerase chain reaction (RT-PCR); immunohistochemistry (IHC) was performed for the detection of iNOS, eNOS, and OPN protein in lung tissues.Results OPN KO mice developed more severe acute lung injury at 72 hours of hyperoxia. The wet/dry weight ratio increased to 6.85±0.66 in the KO mice at 72 hours of hyperoxia as compared to 5.31±0.92 in the WT group (P<0.05). iNOS mRNA (48 hours: 1.04±0.08 vs. 0.63±0.09, P<0.01; 72 hours: 0.89±0.08 vs. 0.72±0.09, P<0.05) and eNOS mRNA (48 hours: 0.62±0.08 vs. 0.43±0.09, P<0.05; 72 hours: 0.67±0.08 vs. 0.45±0.09, P<0.05) expression was more significantly increased in OPN KO mice than their matched WT mice when exposed to hyperoxia. IHC study showed higher expression of iNOS (20.54±3.18 vs. 12.52±2.46, P <0.05) and eNOS (19.83±5.64 vs. 9.45±3.82, P <0.05) in lung tissues of OPN KO mice at 72 hours of hyperoxia. Conclusion OPN can protect against hyperoxia-induced lung

  14. Active site cysteine-null glyceraldehyde-3-phosphate dehydrogenase (GAPDH) rescues nitric oxide-induced cell death.

    Science.gov (United States)

    Kubo, Takeya; Nakajima, Hidemitsu; Nakatsuji, Masatoshi; Itakura, Masanori; Kaneshige, Akihiro; Azuma, Yasu-Taka; Inui, Takashi; Takeuchi, Tadayoshi

    2016-02-29

    Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a homotetrameric enzyme involved in a key step of glycolysis, also has a role in mediating cell death under nitrosative stress. Our previous reports suggest that nitric oxide-induced intramolecular disulfide-bonding GAPDH aggregation, which occurs through oxidation of the active site cysteine (Cys-152), participates in a mechanism to account for nitric oxide-induced death signaling in some neurodegenerative/neuropsychiatric disorders. Here, we demonstrate a rescue strategy for nitric oxide-induced cell death accompanied by GAPDH aggregation in a mutant with a substitution of Cys-152 to alanine (C152A-GAPDH). Pre-incubation of purified wild-type GAPDH with C152A-GAPDH under exposure to nitric oxide inhibited wild-type GAPDH aggregation in a concentration-dependent manner in vitro. Several lines of structural analysis revealed that C152A-GAPDH extensively interfered with nitric oxide-induced GAPDH-amyloidogenesis. Overexpression of doxycycline-inducible C152A-GAPDH in SH-SY5Y neuroblastoma significantly rescued nitric oxide-induced death, concomitant with the decreased formation of GAPDH aggregates. Further, both co-immunoprecipitation assays and simulation models revealed a heterotetramer composed of one dimer each of wild-type GAPDH and C152A-GAPDH. These results suggest that the C152A-GAPDH mutant acts as a dominant-negative molecule against GAPDH aggregation via the formation of this GAPDH heterotetramer. This study may contribute to a new therapeutic approach utilizing C152A-GAPDH against brain damage in nitrosative stress-related disorders.

  15. High K+-Induced Relaxation by Nitric Oxide in Human Gastric Fundus

    Science.gov (United States)

    Kim, Dae Hoon; Choi, Woong; Sung, Rohyun; Kim, Hun Sik; Kim, Heon; Yoo, Ra Young; Park, Seon-Mee; Yun, Sei Jin; Song, Young-Jin; Xu, Wen-Xie; Lee, Sang Jin

    2012-01-01

    This study was designed to elucidate high K+-induced relaxation in the human gastric fundus. Circular smooth muscle from the human gastric fundus greater curvature showed stretch-dependent high K+ (50 mM)-induced contractions. However, longitudinal smooth muscle produced stretch-dependent high K+-induced relaxation. We investigated several relaxation mechanisms to understand the reason for the discrepancy. Protein kinase inhibitors such as KT 5823 (1 µM) and KT 5720 (1 µM) which block protein kinases (PKG and PKA) had no effect on high K+-induced relaxation. K+ channel blockers except 4-aminopyridine (4-AP), a voltage-dependent K+ channel (KV) blocker, did not affect high K+-induced relaxation. However, N(G)-nitro-L-arginine and 1H-(1,2,4)oxadiazolo (4,3-A)quinoxalin-1-one, an inhibitors of soluble guanylate cyclase (sGC) and 4-AP inhibited relaxation and reversed relaxation to contraction. High K+-induced relaxation of the human gastric fundus was observed only in the longitudinal muscles from the greater curvature. These data suggest that the longitudinal muscle of the human gastric fundus greater curvature produced high K+-induced relaxation that was activated by the nitric oxide/sGC pathway through a KV channel-dependent mechanism. PMID:23118553

  16. Signal transduction pathway of nitric oxide inducing PC12 cell death

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To study signal transduction pathway of nitric oxideinducing death of PC12 cells.Methods: Cell survival rate was measured with MTT assay, and caspase-3 activity with caspase-3 assay kits after PC12 cells were incubated with sodium nitroprusside (SNP), caspase-3 inhibitor Ⅱ plus SNP or p38 inhibitor-SB203580 plus SNP.Results: SNP induced death of PC12 cells in dose- and time-dependent manner and enhanced caspase-3 activity gradually. Both caspase-3 inhibitor Ⅱ and SB203580 reduced cell death, but SB203580 reduced caspase-3 activity significantly.Conclusions: NO may induce death of PC12 cells through activation of p38 and caspase-3.

  17. IMMUNOLOGICAL FEATURES IN LIVER CIRRHOSIS INDUCED BY HEPATITIS B VIRUS

    Directory of Open Access Journals (Sweden)

    O. I. Urazova

    2007-01-01

    Full Text Available Abstract. A comparative analysis of immunological data was performed in the patients with HBV-induced liver cirrhosis, and in a group of patients with acute and chronic viral hepatitis B (AVHB, CVHB. Activation of B cell immune compartment (increase in CD22+ lymphocytes and IL4, circulating immune complexes in blood was demonstrated in patients with liver cirrhosis, being also associated with increased numbers of CD16+ lymphocytes and T-cell deficiency. It was revealed that the differences are most expressed upon comparison of immunologic data from the patients with liver cirrhosis, and AVHB followed by clearance of the virus. When comparing these groups, the differences in immunological state between the patients with liver cirrhosis and CVHB did not depend on the phase of viral replication or integration.

  18. Radio-resistance induced by nitric oxide to heavy ion irradiation in A172 human glioma cells

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qingming; ZHANG Hong; ZHANG Xingxia

    2007-01-01

    To investigate effects of nitric oxide on cellular radio-sensitivity, three human glioma cell lines, i.e. A172,A172 transfected green fluorescence protein (EGFP) gene (EA172) and A172 transfected inducible nitric oxide synthesis (iNOS) gene (iA172), were irradiated by 12C6+ ions to 0, 1 or 2Gy. Productions of nitric oxide and glutathione (GSH) in A172, EA172 and iA172 were determined by chemical methods, cell cycle was analyzed by flow cytometry at the 24th hour after irradiation, and survival fraction of the cells was measured by colorimetric MTT assay at the 5th day after irradiation. The results showed that the concentrations of nitric oxide and GSH in iA172 were significantly higher than in A172 and EA172; the G2/M stage arrest induced by the 12C6+ ion irradiation was observed in A172 and EA172 but not in iA172 at the 24th hour after exposure; and the survival fraction of iA172 was higher than that of EA172 and iA172. Data suggest that the radio-sensitivity of the A172 was reduced after the iNOS gene transfection.The increase of GSH production and the change of cellular signals such as the cell cycle control induced by nitric oxide may be involved in this radio-resistance.

  19. Endogenous nitric oxide protects against platelet-activating factor-induced bowel injury in the rat.

    Science.gov (United States)

    MacKendrick, W; Caplan, M; Hsueh, W

    1993-08-01

    Platelet-activating factor (PAF) causes bowel necrosis in animal models that is histologically identical to that seen in neonatal necrotizing enterocolitis, but little is known about endogenous mechanisms that might protect against PAF-induced bowel injury. We hypothesized that endogenous nitric oxide might represent such a protective mechanism. Adult male Sprague-Dawley rats were pretreated with 2.5 mg/kg NG-nitro-L-arginine methyl ester (L-NAME), a potent nitric oxide synthase inhibitor, and given injections of 1.5 micrograms/kg PAF 15 min later. Animals treated with normal saline placebo, L-NAME alone, and PAF alone were also studied. Superior mesenteric artery blood flow and blood pressure were continuously recorded. At the end of 2 h or upon death of the animal, hematocrit was measured and intestinal samples were taken for histologic examination and determination of myeloperoxidase activity, a measure of intestinal neutrophil content. Compared with animals given PAF alone, animals pretreated with L-NAME followed by PAF developed significantly worse bowel injury (median injury scores: 2.5 versus 0.5, p = 0.005), hemoconcentration (final hematocrit 65.2 +/- 2.0% versus 53.9 +/- 1.0%, p < 0.001), and intestinal myeloperoxidase activity (12.45 +/- 1.94 U/g versus 6.51 +/- 0.57 U/g, p < 0.01). The last two effects were further accentuated when 10 mg/kg L-NAME was given before PAF. Treatment with sodium nitroprusside, a nitric oxide donor, for 10 min before and after PAF administration reversed the effects of L-NAME. Animals pretreated with phenylephrine rather than L-NAME did not develop worse injury than animals treated with PAF alone despite comparable reductions in superior mesenteric blood flow before PAF treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Ginsenoside-Rg1 Protects the Liver against Exhaustive Exercise-Induced Oxidative Stress in Rats

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    Mallikarjuna Korivi

    2012-01-01

    Full Text Available Despite regular exercise benefits, acute exhaustive exercise elicits oxidative damage in liver. The present study determined the hepatoprotective properties of ginsenoside-Rg1 against exhaustive exercise-induced oxidative stress in rats. Forty rats were assigned into vehicle and ginsenoside-Rg1 groups (0.1 mg/kg bodyweight. After 10-week treatment, ten rats from each group performed exhaustive swimming. Estimated oxidative damage markers, including thiobarbituric acid reactive substance (TBARS (67% and protein carbonyls (56%, were significantly (P<0.01 elevated after exhaustive exercise but alleviated in ginsenoside-Rg1 pretreated rats. Furthermore, exhaustive exercise drastically decreased glutathione (GSH content (∼79% with concurrent decreased superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GSH-Px activities. However, these changes were attenuated in Rg1 group. Additionally, increased xanthine oxidase (XO activity and nitric oxide (NO levels after exercise were also inhibited by Rg1 pretreatment. For the first time, our findings provide strong evidence that ginsenoside-Rg1 can protect the liver against exhaustive exercise-induced oxidative damage.

  1. Effects of Baicalin on Expression of Inducible Nitric Oxide Synthase in Cultured Fibroblasts Stimulated by Cytokines

    Institute of Scientific and Technical Information of China (English)

    毕新岭; 顾军; 聂本勇; 李泉; 刘辉; 米庆胜

    2004-01-01

    Objective: To investigate the effects of baicalin on expression of inducible nitric oxide synthase (iNOS) in fibroblasts and its mechanisms in treating psoriasis. Methods: Fibroblasts cultured in vitro were stimulated with tumor necrosis factor-α(TNF-α), interferon-γ (IFN-γ), interleukin-8 (IL-S) in different groups. iNOS was detected by western blot and immunocytochemistry assay, and in addition, the effects of baicalin on its expression were investigated. Results: Fibroblasts did not express iNOS without cytokine stimulation. When treated for 24 h with 1. 0× 106 U/L TNF-α, 0.2× 106U/L IFN-γ, 0.2× 106 pg/L IL-8 alone or in combinations indicated, fibroblasts produced iNOS when stimulated by TNF-α alone while neither IFN-γ nor IL-8 could induce the production of iNOS. The combination of TNF-α and IL-8 induced a strong expression of iNOS, the combined exposure of three kinds of cytokines showed an even stronger effects. The strongly stained area was in the cytoplasm near the nuclei. Expression of iNOS induced by TNF-α and IL-8 was inhibited by 50 μg/ mi of baicalin. Conclusion: Fibroblasts might express iNOS when stimulated by certain cytokines. Baicalin decreased production of nitric oxide through inhibiting the expression of iNOS, furthermore it reduced inflammation, which might be part of its mechanisms in treating psoriasis.

  2. Effects of Balcalin on Expression of Inducible Nitric Oxide Synthase In Cultured Fibroblasts Stimulated by Cytokines

    Institute of Scientific and Technical Information of China (English)

    毕新岭; 顾军; 聂本勇; 李泉; 刘辉; 米庆胜

    2004-01-01

    Objective: To investigate the effects of baicalin on expression of inducible nitric oxide synthase (iNOS) in fibroblasts and its mechanisms in treating psoriasis. Methods: Fibroblasts cultured in vitro were stimulated with tumor necrosis factor-α((TNF-α), interferon-γ(IFN-γ), interleukin-8 (IL-8) in different groups, iNOS was detected by western blot and immunocytochemistry assay, and in addition, the effects of baicalin on its expression were investigated. Results. Fibroblasts did not express iNOS without cytokine stimulation. When treated for 24 h with 1.0×106 U/L TNF-α, 0.2×106U/L IFN-γ, 0.2×106 pg/L IL-8 alone or in combinations indicated, fibroblasts produced iNOS when stimulated by TNF-α alone while neither IFN-γ nor IL-8 could induce the production of iNOS. The combination of TNF-α and IL-8 induced a strong expression of iNOS, the combined exposure of three kinds of cytokines showed an even stronger effects. The strongly stained area was in the cytoplasm near the nuclei. Expression of iNOS induced by TNF-α and IL-8 was inhibited by 50μg/ ml of baicalin. Conclusion. Fibroblasts might express iNOS when stimulated by certain cytokines. Baicalin decreased production of nitric oxide through inhibiting the expression of iNOS, furthermore it reduced inflammation, which might be part of its mechanisms in treating psoriasis.

  3. Expression of inducible nitric oxide synthase (iNOS) in microglia of the developing quail retina.

    Science.gov (United States)

    Sierra, Ana; Navascués, Julio; Cuadros, Miguel A; Calvente, Ruth; Martín-Oliva, David; Ferrer-Martín, Rosa M; Martín-Estebané, María; Carrasco, María-Carmen; Marín-Teva, José L

    2014-01-01

    Inducible nitric oxide synthase (iNOS), which produce large amounts of nitric oxide (NO), is induced in macrophages and microglia in response to inflammatory mediators such as LPS and cytokines. Although iNOS is mainly expressed by microglia that become activated in different pathological and experimental situations, it was recently reported that undifferentiated amoeboid microglia can also express iNOS during normal development. The aim of this study was to investigate the pattern of iNOS expression in microglial cells during normal development and after their activation with LPS by using the quail retina as model. iNOS expression was analyzed by iNOS immunolabeling, western-blot, and RT-PCR. NO production was determined by using DAR-4M AM, a reliable fluorescent indicator of subcellular NO production by iNOS. Embryonic, postnatal, and adult in situ quail retinas were used to analyze the pattern of iNOS expression in microglial cells during normal development. iNOS expression and NO production in LPS-treated microglial cells were investigated by an in vitro approach based on organotypic cultures of E8 retinas, in which microglial cell behavior is similar to that of the in situ retina, as previously demonstrated in our laboratory. We show here that amoeboid microglia in the quail retina express iNOS during normal development. This expression is stronger in microglial cells migrating tangentially in the vitreal part of the retina and is downregulated, albeit maintained, when microglia differentiate and become ramified. LPS treatment of retina explants also induces changes in the morphology of amoeboid microglia compatible with their activation, increasing their lysosomal compartment and upregulating iNOS expression with a concomitant production of NO. Taken together, our findings demonstrate that immature microglial cells express iNOS during normal development, suggesting a certain degree of activation. Furthermore, LPS treatment induces overactivation of amoeboid

  4. Inhibition of inducible Nitric Oxide Synthase by a mustard gas analog in murine macrophages

    Directory of Open Access Journals (Sweden)

    Smith Milton

    2006-11-01

    Full Text Available Abstract Background 2-Chloroethyl ethyl sulphide (CEES is a sulphur vesicating agent and an analogue of the chemical warfare agent 2,2'-dichlorodiethyl sulphide, or sulphur mustard gas (HD. Both CEES and HD are alkylating agents that influence cellular thiols and are highly toxic. In a previous publication, we reported that lipopolysaccharide (LPS enhances the cytotoxicity of CEES in murine RAW264.7 macrophages. In the present investigation, we studied the influence of CEES on nitric oxide (NO production in LPS stimulated RAW264.7 cells since NO signalling affects inflammation, cell death, and wound healing. Murine macrophages stimulated with LPS produce NO almost exclusively via inducible nitric oxide synthase (iNOS activity. We suggest that the influence of CEES or HD on the cellular production of NO could play an important role in the pathophysiological responses of tissues to these toxicants. In particular, it is known that macrophage generated NO synthesised by iNOS plays a critical role in wound healing. Results We initially confirmed that in LPS stimulated RAW264.7 macrophages NO is exclusively generated by the iNOS form of nitric oxide synthase. CEES treatment inhibited the synthesis of NO (after 24 hours in viable LPS-stimulated RAW264.7 macrophages as measured by either nitrite secretion into the culture medium or the intracellular conversion of 4,5-diaminofluorescein diacetate (DAF-2DA or dichlorofluorescin diacetate (DCFH-DA. Western blots showed that CEES transiently decreased the expression of iNOS protein; however, treatment of active iNOS with CEES in vitro did not inhibit its enzymatic activity Conclusion CEES inhibits NO production in LPS stimulated macrophages by decreasing iNOS protein expression. Decreased iNOS expression is likely the result of CEES induced alteration in the nuclear factor kappa B (NF-κB signalling pathway. Since NO can act as an antioxidant, the CEES induced down-regulation of iNOS in LPS

  5. Nitric oxide induces cell death by regulating anti-apoptotic BCL-2 family members.

    Directory of Open Access Journals (Sweden)

    Colleen M Snyder

    Full Text Available Nitric oxide (NO activates the intrinsic apoptotic pathway to induce cell death. However, the mechanism by which this pathway is activated in cells exposed to NO is not known. Here we report that BAX and BAK are activated by NO and that cytochrome c is released from the mitochondria. Cells deficient in Bax and Bak or Caspase-9 are completely protected from NO-induced cell death. The individual loss of the BH3-only proteins, Bim, Bid, Puma, Bad or Noxa, or Bid knockdown in Bim(-/-/Puma(-/- MEFs, does not prevent NO-induced cell death. Our data show that the anti-apoptotic protein MCL-1 undergoes ASK1-JNK1 mediated degradation upon exposure to NO, and that cells deficient in either Ask1 or Jnk1 are protected against NO-induced cell death. NO can inhibit the mitochondrial electron transport chain resulting in an increase in superoxide generation and peroxynitrite formation. However, scavengers of ROS or peroxynitrite do not prevent NO-induced cell death. Collectively, these data indicate that NO degrades MCL-1 through the ASK1-JNK1 axis to induce BAX/BAK-dependent cell death.

  6. Nitric Oxide Is a Mediator of Antiproliferative Effects Induced by Proinflammatory Cytokines on Pancreatic Beta Cells

    Science.gov (United States)

    Quintana-Lopez, Laura; Blandino-Rosano, Manuel; Perez-Arana, Gonzalo; Lechuga-Sancho, Alfonso; Aguilar-Diosdado, Manuel

    2013-01-01

    Nitric oxide (NO) is involved in several biological processes. In type 1 diabetes mellitus (T1DM), proinflammatory cytokines activate an inducible isoform of NOS (iNOS) in β cells, thus increasing NO levels and inducing apoptosis. The aim of the current study is to determine the role of NO (1) in the antiproliferative effect of proinflammatory cytokines IL-1β, IFN-γ, and TNF-α on cultured islet β cells and (2) during the insulitis stage prior to diabetes onset using the Biobreeding (BB) rat strain as T1DM model. Our results indicate that NO donors exert an antiproliferative effect on β cell obtained from cultured pancreatic islets, similar to that induced by proinflammatory cytokines. This cytokine-induced antiproliferative effect can be reversed by L-NMMA, a general NOS inhibitor, and is independent of guanylate cyclase pathway. Assays using NOS isoform specific inhibitors suggest that the NO implicated in the antiproliferative effect of proinflammatory cytokines is produced by inducible NOS, although not in an exclusive way. In BB rats, early treatment with L-NMMA improves the initial stage of insulitis. We conclude that NO is an important mediator of antiproliferative effect induced by proinflammatory cytokines on cultured β cell and is implicated in β-cell proliferation impairment observed early from initial stage of insulitis. PMID:23840099

  7. Nitric Oxide Is a Mediator of Antiproliferative Effects Induced by Proinflammatory Cytokines on Pancreatic Beta Cells

    Directory of Open Access Journals (Sweden)

    Laura Quintana-Lopez

    2013-01-01

    Full Text Available Nitric oxide (NO is involved in several biological processes. In type 1 diabetes mellitus (T1DM, proinflammatory cytokines activate an inducible isoform of NOS (iNOS in β cells, thus increasing NO levels and inducing apoptosis. The aim of the current study is to determine the role of NO (1 in the antiproliferative effect of proinflammatory cytokines IL-1β, IFN-γ, and TNF-α on cultured islet β cells and (2 during the insulitis stage prior to diabetes onset using the Biobreeding (BB rat strain as T1DM model. Our results indicate that NO donors exert an antiproliferative effect on β cell obtained from cultured pancreatic islets, similar to that induced by proinflammatory cytokines. This cytokine-induced antiproliferative effect can be reversed by L-NMMA, a general NOS inhibitor, and is independent of guanylate cyclase pathway. Assays using NOS isoform specific inhibitors suggest that the NO implicated in the antiproliferative effect of proinflammatory cytokines is produced by inducible NOS, although not in an exclusive way. In BB rats, early treatment with L-NMMA improves the initial stage of insulitis. We conclude that NO is an important mediator of antiproliferative effect induced by proinflammatory cytokines on cultured β cell and is implicated in β-cell proliferation impairment observed early from initial stage of insulitis.

  8. TRPM2 channels mediate acetaminophen-induced liver damage.

    Science.gov (United States)

    Kheradpezhouh, Ehsan; Ma, Linlin; Morphett, Arthur; Barritt, Greg J; Rychkov, Grigori Y

    2014-02-25

    Acetaminophen (paracetamol) is the most frequently used analgesic and antipyretic drug available over the counter. At the same time, acetaminophen overdose is the most common cause of acute liver failure and the leading cause of chronic liver damage requiring liver transplantation in developed countries. Acetaminophen overdose causes a multitude of interrelated biochemical reactions in hepatocytes including the formation of reactive oxygen species, deregulation of Ca(2+) homeostasis, covalent modification and oxidation of proteins, lipid peroxidation, and DNA fragmentation. Although an increase in intracellular Ca(2+) concentration in hepatocytes is a known consequence of acetaminophen overdose, its importance in acetaminophen-induced liver toxicity is not well understood, primarily due to lack of knowledge about the source of the Ca(2+) rise. Here we report that the channel responsible for Ca(2+) entry in hepatocytes in acetaminophen overdose is the Transient Receptor Potential Melanostatine 2 (TRPM2) cation channel. We show by whole-cell patch clamping that treatment of hepatocytes with acetaminophen results in activation of a cation current similar to that activated by H2O2 or the intracellular application of ADP ribose. siRNA-mediated knockdown of TRPM2 in hepatocytes inhibits activation of the current by either acetaminophen or H2O2. In TRPM2 knockout mice, acetaminophen-induced liver damage, assessed by the blood concentration of liver enzymes and liver histology, is significantly diminished compared with wild-type mice. The presented data strongly suggest that TRPM2 channels are essential in the mechanism of acetaminophen-induced hepatocellular death.

  9. The protective effects of dexmedetomidine on liver injury-induced myocardial ischemia reperfusion.

    Science.gov (United States)

    Erer, D; Ozer, A; Arslan, M; Oktar, G L; Iriz, E; Elmas, C; Zor, M H; Tatar, T; Goktas, G

    2014-01-01

    The aim of this study was to evaluate the effect of dexmedetomidine (100 µg/kg-ip) on liver injury-induced myocardial ischemia and reperfusion (IR) in rats. Twenty-four Wistar Albino rats were separated into four groups. There were four experimental groups (Group C (Control; n = 6), Group IR (ischemia-reperfusion, n = 6), Group D (Dexmedetomidine; n = 6) that underwent left thoracotomy and received ip dexmedetomidine without IR administered via 100 µg/kg ip route 30 minutes before ligating the left coronary artery, and Group IR-D (IR-Dexmedetomidine; n = 6). A small plastic snare was threaded through the ligature and placed in contact with the heart. To produce IR, a branch of the left coronary artery was occluded for 30 min followed by two hours of reperfusion. However, after the above procedure, the coronary artery was not occluded or reperfused in the control rats. At the end of the study, liver tissue was obtained for histochemical and immunohistochemical determination.Some part of tissue samples were stained with Masson-trichrome for the evaluation of ultrastructural changes and inducible nitric oxide synthase (iNOS) expression was evaluated in other part of samples for immunohistochemical examination. Histopathological changes were detected in Group IR when compared with Group C. iNOS expression was found to be increased and stronger particularly in the vascular wall, perisinusoidal space and hepatocytes around vena centralis in this group compared to the control group. Perivascular oedema was detected to be decreased in Group IR-D compared to Group IR. It was also observed that the impairment in the radial arrangement of hepatocytes significantly recovered in Group IR-D. The immunoreactivity was found to be significantly decreased in the assessment of iNOS expression in the same group when compared with Group IR. Administration of dexmedetomidine ameliorates liver injury induced by myocardial ischemia and reperfusion (Fig. 8, Ref. 33).

  10. Nitric Oxide Regulates Dark-Induced Leaf Senescence Through EIN2 in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Yun-Han Niu; Fang-Qing Guo

    2012-01-01

    The nitric oxide (NO)-deficient mutant nos1/noa1 exhibited an early leaf senescence phenotype.ETHYLENE INSENSITIVE 2 (EIN2) was previously reported to function as a positive regulator of ethyleneinduced senescence.The aim of this study was to address the question of how NO interacts with ethylene to regulate leaf senescence by characterizing the double mutant ein2-1 nos1/noa1 (Arabidopsis thaliana).Double mutant analysis revealed that the nos1/noa1-mediated,dark-induced early senescence phenotype was suppressed by mutations in EIN2,suggesting that EIN2 is involved in nitric oxide signaling in the regulation of leaf senescence.The results showed that chlorophyll degradation in the double mutant leaves was significantly delayed.In addition,nos1/noa1-mediated impairment in photochemical efficiency and integrity of thylakoid membranes was reverted by EIN2 mutations.The rapid upregulation of the known senescence marker genes in the nos1/noa1 mutant was severely inhibited in the double mutant during leaf senescence.Interestingly,the response of dark-grown nos1/noa1 mutant seedlings to ethylene was similar to that of wild type seedlings.Taken together,our findings suggest that EIN2 is involved in the regulation of early leaf senescence caused by NO deficiency,but NO deficiency caused by NOS1/NOA1 mutations does not affect ethylene signaling.

  11. Manganese-induced oxidative stress in two ontogenetic stages of chamomile and amelioration by nitric oxide.

    Science.gov (United States)

    Kováčik, Jozef; Babula, Petr; Hedbavny, Josef; Švec, Pavel

    2014-02-01

    Impact of manganese (Mn(2+)) excess (100, 500 and 1000 μM over 7 days) on two ontogenetic stages (7-week-old plants and 7-day-old seedlings) of Matricaria chamomilla was compared. Mn excess depressed growth of seedlings (but not germination) and stimulated oxidative stress (ROS and lipid peroxidation) in both plants and seedlings. Growth inhibition could be evoked by higher Mn uptake and higher translocation factor in seedlings than in plants. Total thiols staining revealed elevation in almost all treatments. In 7-week-old plants, activity of peroxidases increased slightly and rather decreased under high Mn doses. Superoxide rather than hydrogen peroxide contributed to visualized ROS presence. Fluorescence of nitric oxide (NO) showed stimulation in plants but decrease in seedlings. Impact of exogenous nitric oxide donor (sodium nitroprusside/SNP) was therefore tested and results showed amelioration of 1000 μM Mn-induced oxidative stress in seedlings (decrease in H2O2 and increase in NO content while antioxidative enzyme activities were variably affected) concomitantly with depleted Mn accumulation. It is concluded that NO participates in tolerance to Mn excess but negative effects of the highest SNP dose were also observed. Extensive fluorescence microscopy is also explanatively discussed.

  12. Peroxynitrite inhibits inducible (type 2) nitric oxide synthase in murine lung epithelial cells in vitro.

    Science.gov (United States)

    Robinson, V K; Sato, E; Nelson, D K; Camhi, S L; Robbins, R A; Hoyt, J C

    2001-05-01

    Peroxynitrite, formed by nitric oxide (NO) and superoxide, can alter protein function by nitrating amino acids such as tyrosine, cysteine, trytophan, or methionine. Inducible nitric oxide synthase (Type 2 NOS or iNOS) converts arginine to citrulline, releasing NO. We hypothesized that peroxynitrite could function as a negative feedback modulator of NO production by nitration of iNOS. Confluent cultures of the murine lung epithelial cell line, LA-4 were stimulated with cytokines to express iNOS, peroxynitrite was added, and the flasks sealed. After 3 h, NO in the headspace above the culture was sampled. Peroxynitrite caused a concentration-dependent decrease in NO. Similar results were obtained when 3-morpholinosydnonimine (SIN-1), a peroxynitrite generator, was added to the flasks. PAPA-NONOate, the NO generator, did not affect the headspace NO. Nitration of the iNOS was confirmed by detection of 3-nitrotyrosine by Western blotting. These data suggest a mechanism for inhibition of NO synthesis at inflammatory sites where iNOS, NO, and superoxide would be expected.

  13. Role of inducible nitric oxide synthase in the pathogenesis of experimental leptospirosis.

    Science.gov (United States)

    Prêtre, Gabriela; Olivera, Noelia; Cédola, Maia; Haase, Santiago; Alberdi, Lucrecia; Brihuega, Bibiana; Gómez, Ricardo M

    2011-09-01

    Nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) is a radical effector molecule of the innate immune system that can directly inhibit pathogen replication. In order to study subsequent iNOS kidney expression in experimental leptospirosis, Golden Syrian hamsters and C3H/HeJ mice were infected intraperitoneally with 10(2) or 10(7) virulent Leptospira interrogans serovar Copenhageni (LIC) strain Fiocruz L1-130. Results showed increased levels of iNOS mRNA and protein in kidneys of infected animals when compared to that in mock-infected animals. To get a deeper insight into the role of iNOS in experimental leptospirosis, both subject species were treated or not treated with 4-aminopyridine (4-AP, 0.3mg/kg), an iNOS inhibitor. Treatment of infected hamsters with 4-AP accelerated the mortality rate to 100% by one day and increased the mortality rate from 20 to 60% in mice at 14 days post-infection. In kidney tissues, 4-AP treatment increased the bacterial burden, as demonstrated through leptospiral DNA quantification by real-time PCR, and aggravated tubulointerstitial nephritis. In addition, iNOS inhibition reduced the specific humoral response against LIC when compared to that in untreated infected animals. According to these results, iNOS expression and the resulting NO have an important role in leptospirosis.

  14. Inhibition of inducible nitric oxide synthase expression by yuccaol C from Yucca schidigera roezl.

    Science.gov (United States)

    Marzocco, Stefania; Piacente, Sonia; Pizza, Cosimo; Oleszek, Wieslaw; Stochmal, Anna; Pinto, Aldo; Sorrentino, Raffaella; Autore, Giuseppina

    2004-08-06

    Yucca schidigera extract finds wide commercial application in foods, cosmetics and pharmaceuticals. In a previous paper we have found as the main constituents of yucca bark, yuccaol A, B and C, new and very unusual spiro-derivatives made up of a C15 unit and a stilbenic portion closely related to resveratrol. This study was performed to examine whether yuccaol A, B or C (0.01-100 microM) could affect cytosolic inducible nitric oxide synthase (iNOS) protein expression and nitric oxide (NO) generation in vitro in Escherichia coli lipopolysaccharide (LPS)-activated J774.A1 macrophage cell line. NO production, detected as NO2-, increased significantly in LPS treated J774.A1 cells from 0.05 +/- 0.03 microM to 16.64 +/- 0.58 microM (P schidigera as anti-inflammatory remedy could be addressed not only to the resveratrol content but also to the presence of yuccaol C. Copyright 2004 Elsevier Inc.

  15. Expression of the Inducible Nitric Oxide Synthase Isoform in Chorionic Villi in the Early Spontaneous Abortion

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To investigate the relationship between inducible nitric oxide synthase (iNOS) and the early spontaneous abortion. , in situ hybridization and immunohistochemistry were used to detect the expression of iNOS in trophoblasts in the early pregnancy with and without spontaneous abortion (group Ⅰ and group Ⅱ ). By light microscopy and computer color magic image analysis system (CMIAS), light density (D) and the positive cell number per statistic square (N/S) in situ hybridization were used to analyze the positive cell index, while total positive cells (N) and the positive unit (Pu) were used in immunohistochemistry. By in situ hybridization, D and N/S in trophoblasts were 0. 35±0. 028, 0. 07±0. 011 respectively in group Ⅰ and 0. 18±0. 016,0. 015±0. 003 in group Ⅱ . In terms of immunohistochemical staining, N and Pu were 0. 058±±0. 007, 11. 94±2. 01 in group Ⅰ and 0. 013±0. 009, 1. 08±0. 35 in group Ⅱ in trophoblasts. Significant differences existed between two groups. It is concluded that the higher nitric oxide produced by the higher expression of iNOS in trophoblasts might play an important role in the early spontaneous abortion.

  16. INDUCTION OF NITRIC OXIDE SYNTHASE AND ASSOCIATED TOXICITY IN LIVERS OF HARDHEAD CATFISH, ARIUS FELIS, FROM CONTROL AND EPIZOOTIC SITES

    Science.gov (United States)

    Earlier work with a live channel catfish (Ictalurus punctatus) pathogen, Edwardsiella ictaluri, demonstrated the induction of nitric oxide synthase (NOS) in the head kidney, paralleling enteric septicemia (Hawke et al. 1981; Schoor and Plumb 1994). However, another study exposing...

  17. Artificial sweetener neohesperidin dihydrochalcone showed antioxidative, anti-inflammatory and anti-apoptosis effects against paraquat-induced liver injury in mice.

    Science.gov (United States)

    Shi, Qiong; Song, Xiufang; Fu, Juanli; Su, Chuanyang; Xia, Xiaomin; Song, Erqun; Song, Yang

    2015-12-01

    The present study evaluated the protective effect of artificial sweetener neohesperidin dihydrochalcone (NHDC) against paraquat (PQ)-induced acute liver injury in mice. A single dose of PQ (75mg/kg body weight, i.p.) induced acute liver toxicity with the evidences of increased liver damage biomarkers, aspartate transaminase (AST) and alanine transaminase (ALT) activities in serum. Consistently, PQ decreased the antioxidant capacity by reducing glutathione peroxidase (GP-X), glutathione-S-transferase (GST) and catalase (CAT) activities, glutathione (GSH) level and total antioxidant capacity (T-AOC), as well as increasing reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) levels. Histopathological examination revealed that PQ induced numerous changes in the liver tissues. Immunochemical staining assay indicated the upregulation of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expressions. However, NHDC ameliorates PQ-induced hepatic toxicity in mice by reversing these parameters. Additionally, NHDC significantly inhibited PQ-induced nuclear factor-kappa B (NF-κB) expression and mitochondrial-driven apoptotic signaling. TUNEL assay confirmed that PQ-induced apoptosis was relieved by NHDC. In conclusion, these findings suggested that NHDC showed potent antioxidant, anti-inflammatory and anti-apoptotic effects against PQ-induced acute liver damage.

  18. Nitric oxide synthase modulates CFA-induced thermal hyperalgesia through cytokine regulation in mice.

    Science.gov (United States)

    Chen, Yong; Boettger, Michael K; Reif, Andreas; Schmitt, Angelika; Uçeyler, Nurcan; Sommer, Claudia

    2010-03-02

    Although it has been largely demonstrated that nitric oxide synthase (NOS), a key enzyme for nitric oxide (NO) production, modulates inflammatory pain, the molecular mechanisms underlying these effects remain to be clarified. Here we asked whether cytokines, which have well-described roles in inflammatory pain, are downstream targets of NO in inflammatory pain and which of the isoforms of NOS are involved in this process. Intraperitoneal (i.p.) pretreatment with 7-nitroindazole sodium salt (7-NINA, a selective neuronal NOS inhibitor), aminoguanidine hydrochloride (AG, a selective inducible NOS inhibitor), L-N(G)-nitroarginine methyl ester (L-NAME, a non-selective NOS inhibitor), but not L-N(5)-(1-iminoethyl)-ornithine (L-NIO, a selective endothelial NOS inhibitor), significantly attenuated thermal hyperalgesia induced by intraplantar (i.pl.) injection of complete Freund's adjuvant (CFA). Real-time reverse transcription-polymerase chain reaction (RT-PCR) revealed a significant increase of nNOS, iNOS, and eNOS gene expression, as well as tumor necrosis factor-alpha (TNF), interleukin-1 beta (IL-1beta), and interleukin-10 (IL-10) gene expression in plantar skin, following CFA. Pretreatment with the NOS inhibitors prevented the CFA-induced increase of the pro-inflammatory cytokines TNF and IL-1beta. The increase of the anti-inflammatory cytokine IL-10 was augmented in mice pretreated with 7-NINA or L-NAME, but reduced in mice receiving AG or L-NIO. NNOS-, iNOS- or eNOS-knockout (KO) mice had lower gene expression of TNF, IL-1beta, and IL-10 following CFA, overall corroborating the inhibitor data. These findings lead us to propose that inhibition of NOS modulates inflammatory thermal hyperalgesia by regulating cytokine expression.

  19. Endothelial Nitric Oxide Mediates Caffeine Antagonism of Alcohol-Induced Cerebral Artery Constriction.

    Science.gov (United States)

    Chang, Jennifer; Fedinec, Alexander L; Kuntamallappanavar, Guruprasad; Leffler, Charles W; Bukiya, Anna N; Dopico, Alex M

    2016-01-01

    Despite preventive education, the combined consumption of alcohol and caffeine (particularly from "energy drinks") continues to rise. Physiologic perturbations by separate intake of ethanol and caffeine have been widely documented. However, the biologic actions of the alcohol-caffeine combination and their underlying subcellular mechanisms have been scarcely studied. Using intravital microscopy on a closed-cranial window and isolated, pressurized vessels, we investigated the in vivo and in vitro action of ethanol-caffeine mixtures on cerebral arteries from rats and mice, widely recognized models to address cerebrovascular pathophysiology and pharmacology. Caffeine at concentrations found in human circulation after ingestion of one to two cups of coffee (10 µM) antagonized the endothelium-independent constriction of cerebral arteries evoked by ethanol concentrations found in blood during moderate-heavy alcohol intoxication (40-70 mM). Caffeine antagonism against alcohol was similar whether evaluated in vivo or in vitro, suggesting independence of systemic factors and drug metabolism, but required a functional endothelium. Moreover, caffeine protection against alcohol increased nitric oxide (NO•) levels over those found in the presence of ethanol alone, disappeared upon blocking NO• synthase, and could not be detected in pressurized cerebral arteries from endothelial nitric-oxide synthase knockout (eNOS(-/-)) mice. Finally, incubation of de-endothelialized cerebral arteries with the NO• donor sodium nitroprusside (10 µM) fully restored the protective effect of caffeine. This study demonstrates for the first time that caffeine antagonizes ethanol-induced cerebral artery constriction and identifies endothelial NO• as the critical caffeine effector on smooth muscle targets. Conceivably, situations that perturb endothelial function and/or NO• availability will critically alter caffeine antagonism of alcohol-induced cerebrovascular constriction without

  20. Dexamethasone prevents granulocyte-macrophage colony-stimulating factor-induced nuclear factor-κB activation, inducible nitric oxide synthase expression and nitric oxide production in a skin dendritic cell line

    Directory of Open Access Journals (Sweden)

    Ana Luísa Vital

    2003-01-01

    Full Text Available Aims: Nitric oxide (NO has been increasingly implicated in inflammatory skin diseases, namely in allergic contact dermatitis. In this work, we investigated the effect of dexamethasone on NO production induced by the epidermal cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF in a mouse fetal skin dendritic cell line.

  1. Roles of nitric oxide in protective effect of berberine in ethanol-induced gastric ulcer mice

    Institute of Scientific and Technical Information of China (English)

    Long-rui PAN; Qiang TANG; Qin FU; Ben-rong HU; Ji-zhou XIANG; Jia-qing QIAN

    2005-01-01

    Aim: To investigate the protective effects of berberine on ethanol-induced gastric ulcer in mice. Methods: Gastric ulcers were induced by oral ingestion of ethanol. Nitric oxide (NO) content was measured, and mRNA expression of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS)were analyzed by reverse transcription-polymerase chain reaction (RT-PCR).Results: The ulcer index (UI) at 1 h, 2 h, 3 h and 6 h after oral administration of ethanol was 23.8± 1.4, 23.3±2.2, 22.3± 1.2 and 20.8± 1.1, respectively. The UI in the berberine-treated groups (5 mg/kg and 50 mg/kg) was less than the control group.The content of NO in the control group was 73.3±7.3 μL/L, 94.0±9.2 μL/L, 109.6±6.4 μL/L and 138.2±10.2 μL/L in gastric juice and 5.8± 1.1 μmol/g protein, 8.3±1.1 μmol/g protein, 9.8± 1.1 μmol/g protein and 11.9± 1.2 μmol/g protein in gastric tissue at 1 h, 2 h, 3 h and 6 h, respectively, after the oral administration of ethanol.The content of NO in the berberine-treated groups (5 mg/kg and 50 mg/kg) was higher than the control group at 1 h after the oral administration of ethanol(P<0.05), and was lower at 6 h (P<0.05). Analysis by RT-PCR showed that expression of eNOS was inhibited but iNOS expression was enhanced by ethanol.However, the expression of eNOS could be enhanced and iNOS expression could be inhibited by berberine (P<0.01). Conclusion: Berberine could significantly protect gastric mucosa from damage by ethanol. This effect may be related to the increased expression of eNOS mRNA and inhibited expression of iNOS mRNA.

  2. Serotonin deficiency exacerbates acetaminophen-induced liver toxicity in mice.

    Science.gov (United States)

    Zhang, Jingyao; Song, Sidong; Pang, Qing; Zhang, Ruiyao; Zhou, Lei; Liu, Sushun; Meng, Fandi; Wu, Qifei; Liu, Chang

    2015-01-29

    Acetaminophen (APAP) overdose is a major cause of acute liver failure. Peripheral 5-hydroxytryptamine (serotonin, 5-HT) is a cytoprotective neurotransmitter which is also involved in the hepatic physiological and pathological process. This study seeks to investigate the mechanisms involved in APAP-induced hepatotoxicity, as well as the role of 5-HT in the liver's response to APAP toxicity. We induced APAP hepatotoxicity in mice either sufficient of serotonin (wild-type mice and TPH1-/- plus 5- Hydroxytryptophan (5-HTP)) or lacking peripheral serotonin (Tph1-/- and wild-type mice plus p-chlorophenylalanine (PCPA)). Mice with sufficient 5-HT exposed to acetaminophen have a significantly lower mortality rate and a better outcome compared with mice deficient of 5-HT. This difference is at least partially attributable to a decreased level of inflammation, oxidative stress and endoplasmic reticulum (ER) stress, Glutathione (GSH) depletion, peroxynitrite formation, hepatocyte apoptosis, elevated hepatocyte proliferation, activation of 5-HT2B receptor, less activated c-Jun NH₂-terminal kinase (JNK) and hypoxia-inducible factor (HIF)-1α in the mice sufficient of 5-HT versus mice deficient of 5-HT. We thus propose a physiological function of serotonin that serotonin could ameliorate APAP-induced liver injury mainly through inhibiting hepatocyte apoptosis ER stress and promoting liver regeneration.

  3. Hydrogen sulfide defends against the cardiovascular risk of Nw-nitro-L-argininemethyl ester-induced hypertension in rats via the nitric oxide/endothelial nitric oxide synthase pathway

    Institute of Scientific and Technical Information of China (English)

    Ji Wenqiang; Liu Shangyu; Dai Jing; Yang Tao; Jiang Xiangming; Duan Xiaocui; Wu Yuming

    2014-01-01

    Background Dyslipidemia caused by liver injury is a significant risk factor for cardiovascular complications.Previous studies have shown that hydrogen sulfide (H2S) protects against multiple cardiovascular disease states in a similar manner as nitric oxide (NO),and NO/endothelial nitric oxide synthase (eNOS) pathway is the key route of NO production.The purpose of this study was to investigate whether H2S can ameliorate the high blood pressure and plasma lipid profile in Nw-nitro-L-argininemethyl ester (L-NAME)-induced hypertensive rats by NO/eNOS pathway.Methods Thirty-six 4-week old Sprague-Dawley (SD) male rats were randomly assigned to 6 groups (n=6):control group,L-NAME group,control + glibenclamide group,control + NaHS group,L-NAME + NaHS group,and L-NAME + NaHS + glibenclamide group.Measurements were made of plasma triglycerides (TG),low-density lipoprotein (LDL),high-density lipoprotein (HDL),total cholesterol (CHO),glutamic-pyruvic transaminase (ALT) levels after 5 weeks.Then measurements of NO level and proteins expression of eNOS,P-eNOS,AKT,P-AKT were made in liver tissue.Results After 5 weeks of L-NAME treatment,the blood pressure,plasma TG ((1.22±0.12) mmol/L in L-NAME group vs.(0.68±0.09) mmol/L in control group; P <0.05) and LDL ((0.54±0.04) mmol/L in L-NAME group vs.(0.28±0.02) mmol/L in control group; P <0.05) concentration were significantly increased,and the plasma HDL ((0.26±0.02) mmol/L in L-NAME group vs.(0.69±0.07) mmol/L in control group; P <0.05) concentration significantly decreased.Meanwhile the rats treated with L-NAME exhibit dysfunctional eNOS,diminished NO levels ((1.36±0.09) mmol/g protein in L-NAME group vs.(2.34±0.06) mmol/g protein in control group; P <0.05) and pathological changes of the liver.H2S therapy can markedly decrease the blood pressure ((37.25±4.46) mmHg at the fifth week; P <0.05),and ameliorate the plasma TG ((0.59±0.06) mmHg),LDL ((0.32±0.04) mmHg),and HDL ((0.46±0.03) mmHg) concentration in L

  4. Molecular Pathogenesis of Liver Steatosis Induced by Hepatitis C Virus

    Institute of Scientific and Technical Information of China (English)

    Jun; Cheng; Min; Li; Ping; Gao; Jin-ling; Dong; Qi; Wang

    2012-01-01

    Liver steatosis is a pathological hallmark in patients with chronic hepatitis C(CHC).Increased lipid uptake,decreased lipid secretion,increased lipid synthesis and decreased lipid degradation are all involved in pathogenesis of steatosis induced by hepatitic C virus(HCV) infection.Level of low density lipoprotein receptor(LDL-R) and activity of peroxisome proliferator-activated receptor(PPAR) α is related to liver uptake of lipid from circulation,and affected by HCV.Secretion via microsomal triglyceride transfer protein(MTTP),and formation of very low density lipoprotein(VLDL) have been hampered by HCV infection.Up-regulation of lipid synthesis related genes,such as sterol regulatory element-binding protein(SREBP)-1,SREBP-2,SREBP-1c,fatty acid synthase(FASN),HMG CoA reductase(HMGCR),liver X receptor(LXR),acetyl-CoA carboxylase 1(ACC1),hepatic CB(1) receptors,retinoid X receptor(RXR) α,were the main stay of liver steatosis pathogenesis.Degradation of lipid in liver is decreased in patients with CHC.There is strong evidence that heterogeneity of HCV core genes of different genotypes affect their effects of liver steatosis induction.A mechanism in which steatosis is involved in HCV life cycle is emerging.

  5. Portal vein embolization induces compensatory hypertrophy of remnant liver

    Institute of Scientific and Technical Information of China (English)

    Jing-Yao Huang; Wei-Zhu Yang; Jian-Jun Li; Na Jiang; Qu-Bin Zheng

    2006-01-01

    AIM: To evaluate the effectiveness and safety of different portal vein branch embolization agents in inducing compensatory hypertrophy of the remnant liver and to offer a theoretic basis for clinical portal vein branch embolization.METHODS: Forty-one adult dogs were included in the experiment and divided into four groups. Five dogs served as a control group, 12 as a gelfoam group, 12as a coil-gelfoam group and 12 as an absolute ethanol group. Left portal vein embolization was performed in each group. The results from the embolization in each group using different embolic agents were compared.The safety of portal vein embolization (PVE) was evaluated by liver function test, computed tomography (CT) and digital subtraction angiography (DSA) of liver and portal veins. Statistical test of variance was performed to analyze the results.RESULTS: Gelfoam used for PVE was inefficient in recanalization of portal vein branch 4 wk after the procedure. The liver volume in groups of coil-gelfoam and absolute ethanol increased 25.1% and 33.18%,respectively. There was no evidence of recanalization of embolized portal vein, hepatic dysfunction, and portal hypertension in coil-gelfoam group and absolute ethanol group.CONCOUSION: Portal vein branch embolization using absolute ethanol and coil-gelfoam could induce atrophy of the embolized lobes and compensatory hypertrophy of the remnant liver. Gelfoam is an inefficient agent.

  6. Environmentally toxicant exposures induced intragenerational transmission of liver abnormalities in mice

    Directory of Open Access Journals (Sweden)

    Mohamed A. Al-Griw

    2017-08-01

    Full Text Available Environmental toxicants such as chemicals, heavy metals, and pesticides have been shown to promote transgenerational inheritance of abnormal phenotypes and/or diseases to multiple subsequent generations following parental and/ or ancestral exposures. This study was designed to examine the potential transgenerational action of the environmental toxicant trichloroethane (TCE on transmission of liver abnormality, and to elucidate the molecular etiology of hepatocyte cell damage. A total of thirty two healthy immature female albino mice were randomly divided into three equal groups as follows: a sham group, which did not receive any treatment; a vehicle group, which received corn oil alone, and TCE treated group (3 weeks, 100 μg/kg i.p., every 4th day. The F0 and F1 generation control and TCE populations were sacrificed at the age of four months, and various abnormalities histpathologically investigated. Cell death and oxidative stress indices were also measured. The present study provides experimental evidence for the inheritance of environmentally induced liver abnormalities in mice. The results of this study show that exposure to the TCE promoted adult onset liver abnormalities in F0 female mice as well as unexposed F1 generation offspring. It is the first study to report a transgenerational liver abnormalities in the F1 generation mice through maternal line prior to gestation. This finding was based on careful evaluation of liver histopathological abnormalities, apoptosis of hepatocytes, and measurements of oxidative stress biomarkers (lipid peroxidation, protein carbonylation, and nitric oxide in control and TCE populations. There was an increase in liver histopathological abnormalities, cell death, and oxidative lipid damage in F0 and F1 hepatic tissues of TCE treated group. In conclusion, this study showed that the biological and health impacts of environmental toxicant TCE do not end in maternal adults, but are passed on to offspring

  7. Long-term prognosis for transplant-free survivors of paracetamol-induced acute liver failure

    DEFF Research Database (Denmark)

    Jepsen, P; Schmidt, L E; Larsen, F S

    2010-01-01

    The prognosis for transplant-free survivors of paracetamol-induced acute liver failure remains unknown.......The prognosis for transplant-free survivors of paracetamol-induced acute liver failure remains unknown....

  8. Pore-forming bacterial toxins potently induce release of nitric oxide in porcine endothelial cells

    Science.gov (United States)

    1993-01-01

    Nitric oxide (NO) is believed to play an important role in sepsis- related hypotension. We examined the effects of two pore-forming bacterial exotoxins, Escherichia coli hemolysin and Staphylococcus aureus alpha-toxin, on NO formation in cultured porcine pulmonary artery endothelial cells. NO was quantified using a difference- spectrophotometric method based on the rapid and stoichiometric reaction of NO with oxyhemoglobin. Endothelial cyclic guanosine monophosphate levels were also monitored. Both exotoxins increased NO synthesis in endothelial cells in a time- and dose-dependent manner to an extent exceeding that observed with the ionophore A23187 or thrombin. The capacity of exotoxins to induce NO formation may be relevant in patients with severe local or systemic bacterial infections. PMID:8391061

  9. Lignans from Arctium lappa and their inhibition of LPS-induced nitric oxide production.

    Science.gov (United States)

    Park, So Young; Hong, Seong Su; Han, Xiang Hua; Hwang, Ji Sang; Lee, Dongho; Ro, Jai Seup; Hwang, Bang Yeon

    2007-01-01

    A new butyrolactone sesquilignan, isolappaol C (1), together with four known lignans, lappaol C (2), lappaol D (3), lappaol F (4), and diarctigenin (5), were isolated from the methanolic extract of the seeds from the Arctium lappa plant. The structure of isolappaol C (1) was determined by spectral analysis including 1D- and 2D-NMR. All the isolates were evaluated for their inhibitory effects on the LPS-induced nitric oxide production using murine macrophage RAW264.7 cells. Lappaol F (4) and diarctigenin (5) strongly inhibited NO production in the LPS-stimulated RAW264.7 cells with IC(50) values of 9.5 and 9.6 microM, respectively.

  10. Human endogenous retrovirus W env increases nitric oxide production and enhances the migration ability of microglia by regulating the expression of inducible nitric oxide synthase

    Institute of Scientific and Technical Information of China (English)

    Ran Xiao; Shan Li; Qian Cao; Xiuling Wang; Qiujin Yan; Xiaoning Tu; Ying Zhu; Fan Zhu

    2017-01-01

    Human endogenous retrovirus W env (HERV-W env) plays a critical role in many neuropsychological diseases such as schizophrenia and multiple sclerosis (MS).These diseases are accompanied by immunological reactions in the central nervous system (CNS).Microglia are important immunocytes in brain inflammation that can produce a gasotransmitter-nitric oxide (NO).NO not only plays a role in the function of neuronal cells but also participates in the pathogenesis of various neuropsychological diseases.In this study,we reported increased NO production in CHME-5 microglia cells after they were transfected with HERV-W env.Moreover,HERV-W env increased the expression and function of human inducible nitric oxide synthase (hiNOS) and enhanced the promoter activity of hiNOS.Microglial migration was also enhanced.These data revealed that HERV-W env might contribute to increase NO production and microglial migration ability in neuropsychological disorders by regulating the expression of inducible NOS.Results from this study might lead to the identification of novel targets for the treatment of neuropsychological diseases,including neuroinflammatory diseases,stroke,and neurodegenerative diseases.

  11. Hemorrhage-induced Vascular Hyporeactivity to Norepinephrine in Select Vasculatures of Rats and the Roles of Nitric Oxide and Endothelin

    Science.gov (United States)

    2003-03-01

    Hepatology 27:755– 764, 1998. 20. Iglarz M, Levy BI, Henrion D: Chronic endothelin-1 induced changes in vascu- lar reactivity in rat resistance...Mitchell JA, Vane JR: Vascular hyporeactivity to vasoconstrictor agents and hemodynamic decompensation in hemorrhagic shock is mediated by nitric oxide

  12. Macrophages in lung tissue from patients with pulmonary emphysema express both inducible and endothelial nitric oxide synthase

    NARCIS (Netherlands)

    van Straaten, JFM; Postma, DS; Coers, W; Noordhoek, JA; Kauffman, HF; Timens, W

    1998-01-01

    To provide information concerning a possible biologic role of nitric oxide (NO) in smoking-related emphysema, we performed immunohistochemical studies in lung tissue from control subjects and patients with mild and severe emphysema We studied the presence of inducible and endothelial NO synthases (i

  13. Nrf2 activation prevents cadmium-induced acute liver injury

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kai C. [Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Liu, Jie J. [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Klaassen, Curtis D., E-mail: cklaasse@kumc.edu [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States)

    2012-08-15

    Oxidative stress plays an important role in cadmium-induced liver injury. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that up-regulates cytoprotective genes in response to oxidative stress. To investigate the role of Nrf2 in cadmium-induced hepatotoxicity, Nrf2-null mice, wild-type mice, kelch-like ECH-associated protein 1-knockdown (Keap1-KD) mice with enhanced Nrf2, and Keap1-hepatocyte knockout (Keap1-HKO) mice with maximum Nrf2 activation were treated with cadmium chloride (3.5 mg Cd/kg, i.p.). Blood and liver samples were collected 8 h thereafter. Cadmium increased serum alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities, and caused extensive hepatic hemorrhage and necrosis in the Nrf2-null mice. In contrast, Nrf2-enhanced mice had lower serum ALT and LDH activities and less morphological alternations in the livers than wild-type mice. H{sub 2}DCFDA (2′,7′-dichlorodihydrofluoresein diacetate) staining of primary hepatocytes isolated from the four genotypes of mice indicated that oxidative stress was higher in Nrf2-null cells, and lower in Nrf2-enhanced cells than in wild-type cells. To further investigate the mechanism of the protective effect of Nrf2, mRNA of metallothionein (MT) and other cytoprotective genes were determined. Cadmium markedly induced MT-1 and MT-2 in livers of all four genotypes of mice. In contrast, genes involved in glutathione synthesis and reducing reactive oxygen species, including glutamate-cysteine ligase (Gclc), glutathione peroxidase-2 (Gpx2), and sulfiredoxin-1 (Srxn-1) were only induced in Nrf2-enhanced mice, but not in Nrf2-null mice. In conclusion, the present study shows that Nrf2 activation prevents cadmium-induced oxidative stress and liver injury through induction of genes involved in antioxidant defense rather than genes that scavenge Cd. -- Highlights: ► Cadmium caused extensive hepatic hemorrhage and necrosis in Nrf2-null mice. ► Keap1-KD and Keap1-HKO mice

  14. TLR4-dependent immune response promotes radiation-induced liver disease by changing the liver tissue interstitial microenvironment during liver cancer radiotherapy.

    Science.gov (United States)

    Zhi-Feng, Wu; Le-Yuan, Zhou; Xiao-Hui, Zhou; Ya-Bo, Gao; Jian-Ying, Zhang; Yong, Hu; Zhao-Chong, Zeng

    2014-12-01

    Liver tissue interstitial fluid (TIF) a special microenvironment around liver cells, which may play a vital role in cell communication during liver injury. Moreover, toll-like receptor 4 (TLR4) is an important trigger of the immune response that may also play a role in liver injuries, including radiation-induced liver disease (RILD). Therefore, the purpose of this study was to identify the roles of the TLR4-dependent immune response and TIFs in RILD after radiation therapy (RT) for liver cancer. This study consisted of two phases, and in the primary phase, the livers of TLR4 mutant (TLR4(-)) and normal (TLR4(+)) mice were irradiated with 30 Gy. TIF was then obtained from mouse livers and assessed by cytokine array analysis 20 days after irradiation, and cytokines in the TIFs, TLR4 and RILD were analyzed. In the second or validation phase, hepatocytes were isolated from TLR4(+) or TLR4(-) mice irradiated with 8 Gy and were co-cultured with TIFs from mouse livers, apoptosis of the hepatocytes was then measured using flow cytometry. We found that severe RILD was accompanied by higher expression of granulocyte macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-related apoptosis inducing ligand (TRAIL) and vascular endothelial growth factor receptor 2(VEGFR-2) in liver TIFs, from in TLR4(+) mice compared with TLR4(-) mice (P livers irradiated, compared with TIFs from TLR4(-) mice that had their livers irradiated or TIFs from unirradiated mice (P liver TIFs.

  15. Reversal by methylene blue of tetanic fade induced in cats by nitric oxide

    Directory of Open Access Journals (Sweden)

    C.R. Ambiel

    1998-03-01

    Full Text Available Previous data from our laboratory have indicated that nitric oxide (NO acting at the presynaptic level increases the amplitude of muscular contraction (AMC of the phrenic-diaphragm preparations isolated from indirectly stimulated rats, but, by acting at the postsynaptic level, it reduces the AMC when the preparations are directly stimulated. In the present study we investigated the effects induced by NO when tetanic frequencies of stimulation were applied to in vivo preparations (sciatic nerve-anterior tibial muscle of the cat. Intra-arterial injection of NO (0.75-1.5 mg/kg induced a dose-dependent increase in the Wedensky inhibition produced by high frequencies of stimulation applied to the motor nerve. Intra-arterial administration of 7.2 µg/kg methylene blue did not produce any change in AMC at low frequencies of nerve stimulation (0.2 Hz, but antagonized the NO-induced Wedensky inhibition. The experimental data suggest that NO-induced Wedensky inhibition may be mediated by the guanylate cyclase-cGMP pathway

  16. Expression of Apoptosis and Inducible Nitric Oxide Synthase in Trophoblastic Cells in Early Spontaneous Abortion

    Institute of Scientific and Technical Information of China (English)

    夏革清; 孙永玉

    2001-01-01

    Objective To investigate the effect of apoptosis and inducible nitric oxide (Inos) on the early spontaneous abortion Methods TUNEL method was used to detect the apoptosis in trophoblast cells in early pregnancy with and without spontaneous abortion (the experiment group and the control group), while Inos was detected by both in situ hybridization and immunohis tochemistry. By computer color magic image analysis system (CMIAS), positive cell indexes were represented by D (density) and N/S (number/square) in both apoptosis and in situ hybridization, in immunohistochemistry were N/S and PU (positive unit).Results Positive cell indexes of apoptosis D and N/S were significntly higher in the experiment group (0. 48± 0. 004, 0. 045±0. 002) than that in the control group( 0. 35 +0. 06, 0. 031±0. 003. P<0. 001). D and N/S of inducible nitric oxide synthase in situ hybridization were 0. 33± 0. 028, 0. 074± 0. 001 respectively in the experiment group and 0. 13± 0. 015, 0. 019± 0. 004 respectively in the control group. N/S and PU were significantly higher in the experiment group( 0. 058± 0. 007, 11. 94± 2. 01)than that in the control group (0. 007± 0. 001, 1. 18± 0. 35, P<0. 01). There existed a positive correlation between Inos and apoptosis too.Conclution Apoptosis and Inos in trophoblasts might play an important role in early spontaneous abortion and there was a positive correlation between apoptosis and Inos.

  17. Modulation of inducible nitric oxide synthase gene expression in RAW 264.7 murine macrophages by Pacific ciguatoxin

    OpenAIRE

    Kumar-Roine, Shilpa; Matsui, Mariko,; Chinain, M.; Laurent, Dominique; Pauillac, S.

    2008-01-01

    To investigate the possible involvement of the nitric oxide radical (NO) in ciguatera fish poisoning (CFP), the in vitro effects of the main Pacific ciguatoxin (P-CTX-1B) and bacterial lipopolysaccharide (LPS) were comparatively studied on neuroblastoma Neuro-2a and on macrophage RAW 264.7 cell lines. NO accumulation was quantified by measuring nitrite levels in cellular supernatant using Griess reagent while the up-regulation of inducible nitric oxide synthase (iNOS) at the mRNA level was qu...

  18. Nitric Oxide Mediates Molybdenum-Induced Antioxidant Defense in Wheat under Drought Stress

    Directory of Open Access Journals (Sweden)

    Songwei Wu

    2017-06-01

    Full Text Available Molybdenum (Mo has been reported to alleviate drought stress by enhancing antioxidant defense in plants, but the underlying mechanism remains unclear. Here, we hypothesized that Mo mediates nitric oxide (NO-induced antioxidant defense through Mo-enzymes, particularly by nitrate reductase (NR in wheat under drought stress. The 30-day-old wheat seedlings cultivated in -Mo (0 μM Mo and +Mo (1 μM Mo Hoagland solutions were detached and then pretreated with Mo-enzyme inhibitors, NO scavengers, NO donors or their combinations according to demands of complementary experiment under 10% polyethylene glycol 6000 (PEG-stimulated drought stress (PSD. Mo supplementation increased the activities and transcripts of antioxidant enzymes, decreased H2O2 and MDA contents, and elevated NO production, implying that Mo-induced antioxidant defense may be related to NO signal. Complementary experiment showed that NO production was induced by Mo, while suppressed by Mo-enzyme inhibitors and NO scavengers, but restored by NO donors, suggesting that Mo-induced increase of NO production may be due to the regulation by Mo-enzymes. Further experiment indicated that the increased activities and transcripts of antioxidant enzymes induced by Mo were suppressed by Mo-enzyme inhibitors and NO scavengers, and NO donors could eliminate their suppressing effects. Moreover, Mo application increased NR activity and inhibitors of Mo-enzymes inhibited NR activity in wheat leaves under PSD, suggesting that NR might involve in the regulation of Mo-induced NO production. These results clearly indicate that NO mediates Mo-induced antioxidant defense at least partially through the regulation of NR.

  19. Mechanistic Investigation of Toxaphene Induced Mouse Liver Tumors.

    Science.gov (United States)

    Wang, Zemin; Neal, Barbara H; Lamb, James C; Klaunig, James E

    2015-10-01

    Chronic exposure to toxaphene resulted in an increase in liver tumors in B6C3F1 mice. This study was performed to investigate the mode of action of toxaphene induced mouse liver tumors. Following an initial 14 day dietary dose range-finding study in male mice, a mechanistic study (0, 3, 32, and 320 ppm toxaphene in diet for 7, 14, and 28 days of treatment) was performed to examine the potential mechanisms of toxaphene induced mouse liver tumors. Toxaphene induced a significant increase in expression of constitutive androstane receptor (CAR) target genes (Cyp2b10, Cyp3a11) at 32 and 320 ppm toxaphene. aryl hydrocarbon receptor (AhR) target genes (Cyp1a1 and Cyp1a2) were slightly increased in expression at the highest toxaphene dose (320 ppm). No increase in peroxisome proliferator-activated receptor alpha activity or related genes was seen following toxaphene treatment. Lipid peroxidation was seen following treatment with 320 ppm toxaphene. These changes correlated with increases in hepatic DNA synthesis. To confirm the role of CAR in this mode of action, CAR knockout mice (CAR(-/-)) treated with toxaphene confirmed that the induction of CAR responsive genes seen in wild-type mice was abolished following treatment with toxaphene for 14 days. These findings, taken together with previously reported studies, support the mode of action of toxaphene induced mouse liver tumors is through a nongenotoxic mechanism involving primarily a CAR-mediated processes that results in an increase in cell proliferation in the liver, promotes the clonal expansion of preneoplastic lesions leading to adenoma formation.

  20. Contribution of radiation-induced, nitric oxide-mediated bystander effect to radiation-induced adaptive response.

    Science.gov (United States)

    Matsumoto, H.; Ohnishi, T.

    There has been a recent upsurge of interest in radiation-induced adaptive response and bystander effect which are specific modes in stress response to low-dose low-dose rate radiation Recently we found that the accumulation of inducible nitric oxide NO synthase iNOS in wt p53 cells was induced by chronic irradiation with gamma rays followed by acute irradiation with X-rays but not by each one resulting in an increase in nitrite concentrations of medium It is suggested that the accumulation of iNOS may be due to the depression of acute irradiation-induced p53 functions by pre-chronic irradiation In addition we found that the radiosensitivity of wt p53 cells against acute irradiation with X-rays was reduced after chronic irradiation with gamma rays This reduction of radiosensitivity of wt p53 cells was nearly completely suppressed by the addition of NO scavenger carboxy-PTIO to the medium This reduction of radiosensitivity of wt p53 cells is just radiation-induced adaptive response suggesting that NO-mediated bystander effect may considerably contribute to adaptive response induced by radiation

  1. Inducible nitric oxide synthase expression is related to angiogenesis, bcl-2 and cell proliferation in hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    彭佳萍; 郑树; 孝作祥; 张苏展

    2003-01-01

    In this study, we examined the expression of inducible nitric oxide synthase (iNOS) and vascular endothelial growth factor (VEGF) by immunohistochemical staining in 76 tissue sections collected from hepatocellular carcinoma (HCC) patients undergoing hepatectomy. Microvascular density (MVD) was determined by counting endothelial cells immunostained using anti-CD34 antibody. We performed DNA-flow cytometric analyses to elucidate the impact of iNOS and VEGF expression on the cell cycle of HCC. Most of the HCC cells that invaded stroma were markedly immunostained by iNOS antibody. The iNOS stain intensity of the liver tissue close to the tumor edge was stronger than that of HCC tissue, and the strongest was the hepatocytes closer to the tumor tissue. However, iNOS expression in 10 normal hepatic samples was undetectable. VEGF positive expression ratio was 84.8% in iNOS positive expression cases, and the ratio was 35.3% in negative cases. There was significant correlation (P=0.000) between iNOS and VEGF expression. Moreover, iNOS expression was significantly associated with bcl-2 and MVD, but without p53 expression. DNA-flow cytometric analyses showed that combined expression of iNOS and VEGF had significant impact on the cell cycle in HCC. PI (Proliferating Index) and SPF (S-phase fraction) in the combined positive expression of iNOS and VEGF group was significantly higher than that in the combined negative group. The present findings suggested that iNOS expression was significantly associated with angiogenesis, bcl-2 and cell proliferation of HCC.

  2. Genetic association studies in drug-induced liver injury.

    Science.gov (United States)

    Daly, Ann K; Day, Chris P

    2009-11-01

    Genetic studies on drug-induced liver injury (DILI) have proved challenging, both because of their rarity and their difficulty in replicating observed effects. However, significant progress has now been achieved by both candidate-gene and genome-wide association studies. These two approaches are considered in detail, together with examples of DILI due to specific drugs where consistent associations have been reported. Particular consideration is given to associations between antituberculosis drug-related liver injury and the "slow acetylator" genotype for N-acetyltransferase 2, amoxicillin/clavulanate-related liver injury, and the human leukocyte antigen (HLA) class II DRB1*1501 allele and flucloxacillin-related injury and the HLA class I B*5701 allele. Although these associations are drug-specific, the possibility that additional, more general susceptibility genes for DILI exist requires further investigation, ideally by genome-wide association studies involving international collaboration. The possibility of interethnic variation in susceptibility to DILI also requires further study.

  3. Neuronal nitric oxide synthase immunoreactivity in the guinea-pig liver: distribution and colocalization with neuropeptide Y and calcitonin gene-related peptide.

    Science.gov (United States)

    Esteban, F J; Jiménez, A; Fernández, A P; del Moral, M L; Sánchez-López, A M; Hernández, R; Garrosa, M; Pedrosa, J A; Rodrigo, J; Peinado, M A

    2001-12-01

    The innervation pattern of the guinea-pig liver is similar to that of the human liver. However, many aspects of the distribution of the neuronal isoform of the enzyme nitric oxide synthase (nNOS) in the guinea-pig liver and its colocalization with neuropeptides remain to be elucidated. The distribution of nNOS was studied in fixed guinea-pig liver by light microscopic immunohistochemistry. Confocal analysis was used to determine its colocalization with neuropeptide Y (NPY) or calcitonin gene-related peptide (CGRP). nNOS-immunoreactive (nNOS-IR) nerves were observed in relation to hilar and interlobar vessels and in Glisson's capsule. A few nNOS-IR ganglia were observed in the extrahepatic bile duct and close to the interlobar portal triads. In addition, nNOS-IR fibers were located in the interlobular portal triads and pervading the parenchyma. Moreover, nNOS-IR nerves were demonstrated for the first time in the larger central veins and in the hepatic vein. nNOS-NPY and nNOS-CGRP colocalizations were detected in the fibromuscular layer of the bile duct and periductal plexus, respectively. These results support the phylogenetic conservation of the nNOS-IR hepatic innervation and its possible contribution to the regulation of hepatic blood flow and certain hepatic functions.

  4. Effects of nitric oxide (NO) on platelet-activating factor (PAF)- and. alpha. -adrenergic-stimulated vasoconstriction and glycogenolysis in the perfused rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Moy, J.A.; Bates, J.N.; Fisher, R.A. (Univ. of Iowa, Iowa City (United States))

    1991-03-11

    Effects of NO on hemodynamic and glycogenolytic responses to platelet-activating factor (PAF) and phenylephrine were investigated in perfused livers derived from fed rats. Infusion of NO into perfused livers inhibited PAF-induced increases in hepatic glucose output and portal pressure approximately 90% and 85%, respectively, and abolished effects of PAF on hepatic oxygen consumption. NO attenuated PAF-stimulated increases in glucose output and portal pressure, the latter indicative of hepatic vasoconstriction, with a similar dose-dependence with an IC{sub 50} of approximately 8 {mu}M. In contrast to its effects on PAF-induced responses in the perfused liver, NO inhibited increases in hepatic portal pressure in response to phenylephrine approximately 75% without altering phenylephrine-stimulated glucose output and oxygen consumption. Similarly, infusion of NO into perfused livers inhibited significantly increases in hepatic portal pressure but not increases in glucose output in response to a submaximal concentration of phenylephrine. Like NO, sodium nitroprusside significantly inhibited hemodynamic but not glycogenolytic responses to phenylephrine in perfused livers. However, PAF-stimulated alterations in hepatic portal pressure, glucose output and oxygen consumption were unaffected by infusion of sodium nitroprusside into perfused livers. These results provide the first evidence for regulatory effects of NO in the perfused liver and support the contention that PAF, unlike phenylephrine, stimulates glycogenolysis by mechanisms secondary to hepatic vasoconstriction. These observations raise the intriguing possibility that NO may act in liver to regulate hemodynamic responses to vasoactive mediators.

  5. Delineating liver events in trichloroethylene-induced autoimmune hepatitis.

    Science.gov (United States)

    Gilbert, Kathleen M; Przybyla, Beata; Pumford, Neil R; Han, Tao; Fuscoe, James; Schnackenberg, Laura K; Holland, Ricky D; Doss, Jason C; Macmillan-Crow, Lee Ann; Blossom, Sarah J

    2009-04-01

    Exposure to the environmental pollutant trichloroethylene (TCE) has been linked to autoimmune disease development in humans. Chronic (32-week) low-level exposure to TCE has been shown to promote autoimmune hepatitis in association with CD4(+) T cell activation in autoimmune-prone MRL+/+ mice. MRL+/+ mice are usually thought of as a model of systemic lupus rather than an organ-specific disease such as autoimmune hepatitis. Consequently, the present study examined gene expression and metabolites to delineate the liver events that skewed the autoimmune response toward that organ in TCE-treated mice. Female MRL+/+ mice were treated with 0.5 mg/mL TCE in their drinking water. The results showed that TCE-induced autoimmune hepatitis could be detected in as little as 26 weeks. TCE exposure also generated a time-dependent increase in the number of antibodies specific for liver proteins. The gene expression correlated with the metabolite analysis to show that TCE upregulated the methionine/homocysteine pathway in the liver after 26 weeks of exposure. The results also showed that TCE exposure altered the expression of selective hepatic genes associated with immunity and inflammation. On the basis of these results, future mechanistic studies will focus on how alterations in genes associated with immunity and inflammation, in conjunction with protein alterations in the liver, promote liver immunogenicity in TCE-treated MRL+/+ mice.

  6. Nitric oxide protects carbon assimilation process of watermelon from boron-induced oxidative injury.

    Science.gov (United States)

    Farag, Mohamed; Najeeb, Ullah; Yang, Jinghua; Hu, Zhongyuan; Fang, Zhang Ming

    2017-02-01

    Nitric oxide (NO) mediates plant response to a variety of abiotic stresses; however, limited information is available on its effect on boron (B)-stressed watermelon plants. The present study investigates the mechanism through which NO protects watermelon seedlings from B deficiency and toxicity stresses. Five days old watermelon seedlings were exposed to B (0, 0.5 and 10 mg L(-1)) alone or with 75 μmole of NO donor sodium nitroprusside (SNP) for 30 days. Both low and high B concentrations in the media altered nutrient accumulation and impaired various physiological processes of watermelon seedlings, leading to a significant reduction in biomass production. The plants exposed to B deficient or toxic concentrations had 66 and 69% lower shoot dry weight, respectively compared with optimum B levels. B toxicity-induced growth inhibition of watermelon seedlings was associated with high B translocation to shoot tissues, which caused lipid membrane peroxidation (12% increase) and chlorophyll destruction (25% reduction). In contrast, B deficiency accelerated generation of reactive oxygen species (ROS), specifically OH(-1) and induced cellular oxidative injury. Exogenously applied SNP promoted leaf chlorophyll, photosynthesis and consequently biomass production in B-stressed watermelon seedlings by reducing B accumulation, lipid membrane peroxidation and ROS generation. It also activated antioxidant enzymes such as SOD, POD and APX, and protected the seedlings from ROS-induced cellular burst.

  7. Expression of a nitric oxide degrading enzyme induces a senescence programme in Arabidopsis.

    Science.gov (United States)

    Mishina, Tatiana E; Lamb, Chris; Zeier, Jürgen

    2007-01-01

    Nitric oxide (NO) has been proposed to act as a factor delaying leaf senescence and fruit maturation in plants. Here we show that expression of a NO degrading dioxygenase (NOD) in Arabidopsis thaliana initiates a senescence-like phenotype, an effect that proved to be more pronounced in older than in younger leaves. This senescence phenotype was preceded by a massive switch in gene expression in which photosynthetic genes were down-regulated, whereas many senescence-associated genes (SAGs) and the 1-aminocyclopropane-1-carboxylic acid (ACC) synthase gene ACS6 involved in ethylene synthesis were up-regulated. External fumigation of NOD plants with NO as well as environmental conditions known to stimulate endogenous NO production attenuated the induced senescence programme. For instance, both high light conditions and nitrate feeding reduced the senescence phenotype and attenuated the down-regulation of photosynthetic genes as well as the up-regulation of SAGs. Treatment of plants with the cytokinin 6-benzylaminopurin (BAP) reduced the down-regulation of photosynthesis, although it had no consistent effect on SAG expression. Metabolic changes during NOD-induced senescence comprehended increases in salicylic acid (SA) levels, accumulation of the phytoalexin camalexin and elevation of leaf gamma-tocopherol contents, all of which occurred during natural senescence in Arabidopsis leaves as well. Moreover, NO fumigation delayed the senescence process induced by darkening individual Arabidopsis Columbia-0 (Col-0) leaves. Our data thus support the notion that NO acts as a negative regulator of leaf senescence.

  8. Central blockade of nitric oxide synthesis reduces moxonidine-induced hypotension.

    Science.gov (United States)

    Moreira, Thiago Santos; Takakura, Ana Carolina Thomaz; Menani, José V; Sato, Monica Akemi; Colombari, Eduardo

    2004-06-01

    1. Nitric oxide (NO) and alpha(2)-adrenoceptor and imidazoline agonists such as moxonidine may act centrally to inhibit sympathetic activity and decrease arterial pressure. 2. In the present study, we investigated the effects of pretreatment with l-NAME (NO synthesis inhibitor), injected into the 4th ventricle (4th V) or intravenously (i.v.), on the hypotension, bradycardia and vasodilatation induced by moxonidine injected into the 4th V in normotensive rats. 3. Male Wistar rats with a stainless steel cannula implanted into the 4th V and anaesthetized with urethane were used. Blood flows were recorded by use of miniature pulsed Doppler flow probes implanted around the renal, superior mesenteric and low abdominal aorta. 4. Moxonidine (20 nmol), injected into the 4th V, reduced the mean arterial pressure (-42+/-3 mmHg), heart rate (-22+/-7 bpm) and renal (-62+/-15%), mesenteric (-41+/-8%) and hindquarter (-50+/-8%) vascular resistances. 5. Pretreatment with l-NAME (10 nmol into the 4th V) almost abolished central moxonidine-induced hypotension (-10+/-3 mmHg) and renal (-10+/-4%), mesenteric (-11+/-4%) and hindquarter (-13+/-6%) vascular resistance reduction, but did not affect the bradycardia (-18+/-8 bpm). 6. The results indicate that central NO mechanisms are involved in the vasodilatation and hypotension, but not in the bradycardia, induced by central moxonidine in normotensive rats.

  9. Dehydroepiandrosterone inhibits lipopolysaccharide-induced nitric oxide production in BV-2 microglia.

    Science.gov (United States)

    Wang, M J; Huang, H M; Chen, H L; Kuo, J S; Jeng, K C

    2001-05-01

    Levels of dehydroepiandrosterone (DHEA) and its sulfated derivative (DHEAS) decline during aging and reach even lower levels in Alzheimer's disease (AD). DHEA is known to exhibit a variety of functional activities in the CNS, including an increase of memory and learning, neurotrophic and neuroprotective effects, and the reduction of risk of age-related neurodegenerative disorders. However, the influence of DHEA on the immune functions of glial cells is poorly understood. In this study, we investigated the effect of DHEA on activated glia. The production of inducible nitric oxide synthase (iNOS) was studied in lipopolysaccharide (LPS)-stimulated BV-2 microglia, as a model of glial activation. The results showed that DHEA but not DHEAS significantly inhibited the production of nitrite in the LPS-stimulated BV-2 cell cultures. Pretreatment of BV-2 cells with DHEA reduced the LPS-induced iNOS mRNA and protein levels in a dose-dependent manner. The LPS-induced iNOS activity in BV-2 cells was decreased by the exposure of 100 microM DHEA. Moreover, DHEA suppressed iNOS gene expression in LPS-stimulated BV-2 cells did not require de novo synthesis of new proteins or destabilize of iNOS mRNA. Since DHEA is biosynthesized by astrocytes and neurons, our findings suggest that it might have an important regulatory function on microglia.

  10. Sucrose-induced analgesia in mice: Role of nitric oxide and opioid receptor-mediated system

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    Abtin Shahlaee

    2013-01-01

    Full Text Available Background: The mechanism of action of sweet substance-induced analgesia is thought to involve activation of the endogenous opioid system. The nitric oxide (NO pathway has a pivotal role in pain modulation of analgesic compounds such as opioids. Objectives: We investigated the role of NO and the opioid receptor-mediated system in the analgesic effect of sucrose ingestion in mice. Materials and Methods: We evaluated the effect of intraperitoneal administration of 10 mg/kg of NO synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME and 20 mg/kg of opioid receptor antagonist, naltrexone on the tail flick response in sucrose ingesting mice. Results: Sucrose ingestion for 12 days induced a statistically significant increase in the latency of tail flick response which was unmodified by L-NAME, but partially inhibited by naltrexone administration. Conclusions: Sucrose-induced nociception may be explained by facilitating the release of endogenous opioid peptides. Contrary to some previously studied pain models, the NO/cyclic guanosine monophosphate (cGMP pathway had no role in thermal hyperalgesia in our study. We recommend further studies on the involvement of NO in other animals and pain models.

  11. Therapeutic insight into molsidomine, a nitric oxide donor in streptozotocin-induced diabetic nephropathy in rats

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    Nathani Minaz

    2016-01-01

    Full Text Available Background: Diabetes-induced oxidative stress and hypertension play a major role in the development of nephropathy. Hence, the present study was undertaken to evaluate the protective effects of molsidomine, a nitric oxide donor in streptozotocin (STZ-induced diabetic nephropathy (DN in rats. Materials and Methods: Type 1 diabetes was induced through a single dose of STZ (52 mg/kg, i.p. in male Wistar rats and then treated with molsidomine (5 and 10 mg/kg; p.o. for 8 weeks. Physical parameters, vital and renal function test including blood glucose, albuminuria, blood urine nitrogen, serum creatinine, and kidney index were determined. Oxidative stress and lipid peroxidation were assessed in the kidney homogenate by means of antioxidant enzymes and malondialdehyde levels. Results: DN rats exhibited a significant renal dysfunction with a reduction in body weight, excessive oxidative stress, and pathological changes. Molsidomine treatment significantly improved vital sign, renal functions, and oxidative stress in DN rats in a dose-dependent manner. The protective effect of molsidomine was also substantiated by pathological changes in the architect of the kidney. Conclusion: Molsidomine shows a significant beneficial effect in Type 1 DN in rats.

  12. Nitric oxide ameliorates zinc oxide nanoparticles-induced phytotoxicity in rice seedlings.

    Science.gov (United States)

    Chen, Juan; Liu, Xiang; Wang, Chao; Yin, Shan-Shan; Li, Xiu-Ling; Hu, Wen-Jun; Simon, Martin; Shen, Zhi-Jun; Xiao, Qiang; Chu, Cheng-Cai; Peng, Xin-Xiang; Zheng, Hai-Lei

    2015-10-30

    Nitric oxide (NO) has been found to function in enhancing plant tolerance to various environmental stresses. However, role of NO in relieving zinc oxide nanoparticles (ZnO NPs)-induced phytotoxicity remains unknown. Here, sodium nitroprusside (SNP, a NO donor) was used to investigate the possible roles and the regulatory mechanisms of NO in counteracting ZnO NPs toxicity in rice seedlings. Our results showed that 10 μM SNP significantly inhibited the appearance of ZnO NP toxicity symptoms. SNP addition significantly reduced Zn accumulation, reactive oxygen species production and lipid peroxidation caused by ZnO NPs. The protective role of SNP in reducing ZnO NPs-induced oxidative damage is closely related to NO-mediated antioxidant system. A decrease in superoxide dismutase activity, as well as an increase in reduced glutathione content and peroxidase, catalase and ascorbate peroxidase activity was observed under SNP and ZnO NPs combined treatments, compared to ZnO NPs treatment alone. The relative transcript abundance of corresponding antioxidant genes exhibited a similar change. The role of NO in enhancing ZnO NPs tolerance was further confirmed by genetic analysis using a NO excess mutant (noe1) and an OsNOA1-silenced plant (noa1) of rice. Together, this study provides the first evidence indicating that NO functions in ameliorating ZnO NPs-induced phytotoxicity.

  13. Lipid peroxidation and cell death mechanisms in pulmonary epithelial cells induced by peroxynitrite and nitric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Yuan-Soon [School of Medical Technology, Taipei Medical University, Taipei (Taiwan); Liou, Hung-Bin; Lin, Yu-Ping; Guo, How-Ran; Ho, Sheng-Yow; Lee, Ching-Chang; Wang, Ying-Jan [Department of Environmental and Occupational Health, National Cheng Kung University Medical College, 138 Sheng-Li Road, Tainan (Taiwan); Lin, Jen-Kun; Pan, Min-Hsiung [Institute of Biochemistry, National Taiwan University, Medical College, Taipei (Taiwan); Jeng, Jiiang-Huei [School of Dentistry, National Taiwan University and Hospital, Medical College, Taipei (Taiwan)

    2002-08-01

    Nitric oxide (NO) is an environmental pollutant found in smog and cigarette smoke. Recently, NO has been discovered to act as a molecular messenger, mediating various physiological functions. However, when an excess of NO is present, cytotoxic and mutagenic effects can also be induced. The reaction of NO with superoxide results in the formation of peroxynitrite (ONOO{sup -}), which decomposes into the hydroxyl radical and nitrogen dioxide. Both of them are potent oxidant species that may initiate and propagate lipid peroxidation. In the present study, we examined the effects of NO and ONOO{sup -} on the induction of lipid peroxidation and cell death mechanisms in rats and in A549 pulmonary epithelial cells. The results showed that ONOO{sup -} is able to induce lipid peroxidation in pulmonary epithelial cells in a dose-dependent manner. 8-Epi-prostaglandin F{sub 2{alpha}} can serve as a good biomarker of lipid peroxidation both in vitro and in vivo. Postmitotic apoptosis was found in A549 cells exposed to NO, whereas ONOO{sup -} induced cell death more characteristic of necrosis than apoptosis. Apoptosis that occurred in cells may be related to the dysfunction of mitochondria, the release of cytochrome c into cytosol, and the activation of caspase-9. The relationship between caspase activation and the cleavage of other death substrates during postmitotic apoptosis in A549 cells needs further investigation. (orig.)

  14. L-arginine, a nitric oxide precursor, reduces dapsone-induced methemoglobinemia in rats

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    Natália Valadares de Moraes

    2012-03-01

    Full Text Available Dapsone use is frequently associated to hematological side effects such as methemoglobinemia and hemolytic anemia, which are related to N-hydroxylation mediated by the P450 enzyme system. The aim of the present study was to evaluate the influence of L-arginine supplementation, a precursor for the synthesis of nitric oxide, as single or multiple dose regimens on dapsone-induced methemoglobinemia. Male Wistar rats were treated with L-arginine at 5, 15, 30, 60 and 180 mg/kg doses (p.o., gavage in single or multiple dose regimens 2 hours prior to dapsone administration (40 mg/kg, i.p.. The effect of the nitric oxide synthase inhibitor L-NAME was investigated by treatment with multiple doses of 30 mg/kg (p.o., gavage 2 hours before dapsone administration. Blood samples were collected 2 hours after dapsone administration. Erythrocytic methemoglobin levels were assayed by spectrophotometry. The results showed that multiple dose supplementations with 5 and 15 mg/kg L-arginine reduced dapsone-induced methemoglobin levels. This effect is mediated by nitric oxide formation, since the reduction in methemoglobin levels by L-arginine is blocked by simultaneous administration with L-NAME, a nitric oxide synthase inhibitor.O uso da dapsona é frequentemente associado a efeitos adversos hematológicos, como a metemoglobinemia e anemia hemolítica, ambos relacionados com a N-hidroxilação mediada pelo sistema P450. O objetivo do estudo foi avaliar a influência da suplementação de L-arginina, um precursor da síntese de óxido nítrico, administrado em regime de dose única ou múltipla na metemoglobinemia induzida pela dapsona. Ratos machos Wistar foram tratados com L-arginina (po, gavagem em dose única ou múltipla de 5, 15, 30, 60 e 180 mg/kg 2 horas antes da administração de dapsona (40 mg/kg, ip. O efeito do L-NAME, um inibidor de óxido nítrico sintase (NOS, foi avaliado através do tratamento com doses múltiplas de 30 mg/kg. Amostras de sangue

  15. Ebselen prevents early alcohol-induced liver injury in rats.

    Science.gov (United States)

    Kono, H; Arteel, G E; Rusyn, I; Sies, H; Thurman, R G

    2001-02-15

    Oxidants have been shown to be involved in alcohol-induced liver injury. Moreover, 2-phenyl-1,2-benzisoselenazole-3(2H)-one (ebselen), an organoselenium compound and glutathione peroxidase mimic, decreases oxidative stress and protects against stroke clinically. This study was designed to test the hypothesis that ebselen protects against early alcohol-induced liver injury in rats. Male Wistar rats were fed high-fat liquid diets with or without ethanol (10-16 g/kg/d) continuously for up to 4 weeks using the intragastric enteral feeding protocol developed by Tsukamoto and French. Ebselen (50 mg/kg twice daily, intragastrically) or vehicle (1% tylose) was administered throughout the experiment. Mean urine ethanol concentrations were not significantly different between treatment groups, and ebselen did not affect body weight gains or cyclic patterns of ethanol concentrations in urine. After 4 weeks, serum ALT levels were increased significantly about 4-fold over control values (37 +/- 5 IU/l) by enteral ethanol (112 +/- 7 IU/l); ebselen blunted this increase significantly (61 +/- 8 IU/l). Enteral ethanol also caused severe fatty accumulation, mild inflammation, and necrosis in the liver (pathology score: 4.3 +/- 0.3). In contrast, these pathological changes were blunted significantly by ebselen (pathology score: 2.5 +/- 0.4). While there were no significant effects of either ethanol or ebselen on glutathione peroxidase activity in serum or liver tissue, ebselen blocked the increase in serum nitrate/nitrite caused by ethanol. Furthermore, ethanol increased the activity of NF-kappaB over 5-fold, the number of infiltrating neutrophils 4-fold, and the accumulation of 4-hydroxynonenal over 5-fold. Ebselen blunted all of these effects significantly. These results indicate that ebselen prevents early alcohol-induced liver injury, most likely by preventing oxidative stress, which decreases inflammation.

  16. Novel mechanism of arenavirus-induced liver pathology.

    Directory of Open Access Journals (Sweden)

    Juliane I Beier

    Full Text Available Viral hemorrhagic fevers (VHFs encompass a group of diseases with cardinal symptoms of fever, hemorrhage, and shock. The liver is a critical mediator of VHF disease pathogenesis and high levels of ALT/AST transaminases in plasma correlate with poor prognosis. In fact, Lassa Fever (LF, the most prevalent VHF in Africa, was initially clinically described as hepatitis. Previous studies in non-human primate (NHP models also correlated LF pathogenesis with a robust proliferative response in the liver. The purpose of the current study was to gain insight into the mechanism of liver injury and to determine the potential role of proliferation in LF pathogenesis. C57Bl/6J mice were infected with either the pathogenic (for NHPs strain of lymphocytic choriomeningitis virus (LCMV, the prototypic arenavirus, LCMV-WE, or with the non-pathogenic strain, LCMV-ARM. As expected, LCMV-WE, but not ARM, caused a hepatitis-like infection. LCMV-WE also induced a robust increase in the number of actively cycling hepatocytes. Despite this increase in proliferation, there was no significant difference in liver size between LCMV-WE and LCMV-ARM, suggesting that cell cycle was incomplete. Indeed, cells appeared arrested in the G1 phase and LCMV-WE infection increased the number of hepatocytes that were simultaneously stained for proliferation and apoptosis. LCMV-WE infection also induced expression of a non-conventional virus receptor, AXL-1, from the TAM (TYRO3/AXL/MERTK family of receptor tyrosine kinases and this expression correlated with proliferation. Taken together, these results shed new light on the mechanism of liver involvement in VHF pathogenesis. Specifically, it is hypothesized that the induction of hepatocyte proliferation contributes to expansion of the infection to parenchymal cells. Elevated levels of plasma transaminases are likely explained, at least in part, by abortive cell cycle arrest induced by the infection. These results may lead to the

  17. Ketogenesis prevents diet-induced fatty liver injury and hyperglycemia.

    Science.gov (United States)

    Cotter, David G; Ercal, Baris; Huang, Xiaojing; Leid, Jamison M; d'Avignon, D André; Graham, Mark J; Dietzen, Dennis J; Brunt, Elizabeth M; Patti, Gary J; Crawford, Peter A

    2014-12-01

    Nonalcoholic fatty liver disease (NAFLD) spectrum disorders affect approximately 1 billion individuals worldwide. However, the drivers of progressive steatohepatitis remain incompletely defined. Ketogenesis can dispose of much of the fat that enters the liver, and dysfunction in this pathway could promote the development of NAFLD. Here, we evaluated mice lacking mitochondrial 3-hydroxymethylglutaryl CoA synthase (HMGCS2) to determine the role of ketogenesis in preventing diet-induced steatohepatitis. Antisense oligonucleotide-induced loss of HMGCS2 in chow-fed adult mice caused mild hyperglycemia, increased hepatic gluconeogenesis from pyruvate, and augmented production of hundreds of hepatic metabolites, a suite of which indicated activation of the de novo lipogenesis pathway. High-fat diet feeding of mice with insufficient ketogenesis resulted in extensive hepatocyte injury and inflammation, decreased glycemia, deranged hepatic TCA cycle intermediate concentrations, and impaired hepatic gluconeogenesis due to sequestration of free coenzyme A (CoASH). Supplementation of the CoASH precursors pantothenic acid and cysteine normalized TCA intermediates and gluconeogenesis in the livers of ketogenesis-insufficient animals. Together, these findings indicate that ketogenesis is a critical regulator of hepatic acyl-CoA metabolism, glucose metabolism, and TCA cycle function in the absorptive state and suggest that ketogenesis may modulate fatty liver disease.

  18. Neonatally induced diabetes: liver glycogen storage in pregnant rats

    Directory of Open Access Journals (Sweden)

    Isabela Lovizutto Iessi

    2012-04-01

    Full Text Available The aim of this sstudy was to evaluate the liver glycogen storage in pregnant rats presenting neonatal streptozotocin-induced diabetes and to establish a relation with glycemia and insulin levels. Wistar rats were divided in to two groups: 1 Mild Diabetes (STZ - received streptozotocin (glycemia from 120 to 300 mg/dL, 2 Control - received vehicle (glycemia below 120 mg/dL. At days 0, 7, 14 and 21 of the pregnancy, body weight and glycemia were evaluated. At day 21 of the pregnancy, the rats were anesthetized for blood and liver collection so as to determine insulin and liver glycogen, which showed no changes in the STZ group as compared to the controls. In the STZ group, maternal weight gain were lower as compared to those in the control group. Significantly increased glycemia was observed at days 0 and 14 of the pregnancy in the STZ group. Therefore, neonatally induced diabetes in the rats did not cause metabolic changes that impaired insulin and liver glycogen relation in these rats.

  19. Role of nitric oxide in hematosuppression and benzene-induced toxicity.

    OpenAIRE

    Laskin, D L; Heck, D E; Punjabi, C J; Laskin, J D

    1996-01-01

    It is becoming increasingly apparent that nitric oxide plays a multifunctional role in regulating inflammatory processes in the body. Although nitric oxide and its oxidation products are cytotoxic toward certain pathogens, they can also cause tissue injury and suppress proliferation. Cytokines and growth factors released at sites of inflammation or injury stimulate both immune and nonimmume cells to produce nitric oxide. Nowhere in the body is this more detrimental than in the bone marrow, fo...

  20. Mas receptor is involved in the estrogen-receptor induced nitric oxide-dependent vasorelaxation.

    Science.gov (United States)

    Sobrino, Agua; Vallejo, Susana; Novella, Susana; Lázaro-Franco, Macarena; Mompeón, Ana; Bueno-Betí, Carlos; Walther, Thomas; Sánchez-Ferrer, Carlos; Peiró, Concepción; Hermenegildo, Carlos

    2017-04-01

    The Mas receptor is involved in the angiotensin (Ang)-(1-7) vasodilatory actions by increasing nitric oxide production (NO). We have previously demonstrated an increased production of Ang-(1-7) in human umbilical vein endothelial cells (HUVEC) exposed to estradiol (E2), suggesting a potential cross-talk between E2 and the Ang-(1-7)/Mas receptor axis. Here, we explored whether the vasoactive response and NO-related signalling exerted by E2 are influenced by Mas. HUVEC were exposed to 10nM E2 for 24h in the presence or absence of the selective Mas receptor antagonist A779, and the estrogen receptor (ER) antagonist ICI182780 (ICI). E2 increased Akt and endothelial nitric oxide synthase (eNOS) mRNA and protein expression, measured by RT-PCR and Western blot, respectively. Furthermore, E2 increased Akt activity (determined by the levels of phospho-Ser(473)) and eNOS activity (by the enhanced phosphorylation of Ser(1177), the activated form), resulting in increased NO production, which was measured by the fluorescence probe DAF-2-FM. These signalling events were dependent on ER and Mas receptor activation, since they were abolished in the presence of ICI or A779. In ex-vivo functional experiments performed with a small-vessel myograph in isolated mesenteric vessels from wild-type mice pre-contracted with noradrenaline, the relaxant response to physiological concentrations of E2 was blocked by ICI and A779, to the same extent to that obtained in the vessels isolated from Mas-deficient. In conclusion, E2 induces NO production and vasodilation through mechanisms that require Mas receptor activation. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Trans fatty acids induce vascular inflammation and reduce vascular nitric oxide production in endothelial cells.

    Directory of Open Access Journals (Sweden)

    Naomi G Iwata

    Full Text Available Intake of trans fatty acids (TFA, which are consumed by eating foods made from partially hydrogenated vegetable oils, is associated with a higher risk of cardiovascular disease. This relation can be explained by many factors including TFA's negative effect on endothelial function and reduced nitric oxide (NO bioavailability. In this study we investigated the effects of three different TFA (2 common isomers of C18 found in partially hydrogenated vegetable oil and a C18 isomer found from ruminant-derived-dairy products and meat on endothelial NF-κB activation and nitric oxide (NO production. Human endothelial cells were treated with increasing concentrations of Elaidic (trans-C18:1 (9 trans, Linoelaidic (trans-C18:2 (9 trans, 12 trans, and Transvaccenic (trans-C18:1 (11 trans for 3 h. Both Elaidic and Linoelaidic acids were associated with increasing NF-κB activation as measured by IL-6 levels and phosphorylation of IκBα, and impairment of endothelial insulin signaling and NO production, whereas Transvaccenic acid was not associated with these responses. We also measured superoxide production, which has been hypothesized to be necessary in fatty acid-dependent activation of NF-κB. Both Elaidic acid and Linoelaidic acid are associated with increased superoxide production, whereas Transvaccenic acid (which did not induce inflammatory responses did not increase superoxide production. We observed differential activation of endothelial superoxide production, NF-κB activation, and reduction in NO production by different C18 isomers suggesting that the location and number of trans double bonds effect endothelial NF-κB activation.

  2. Gomisin J from Schisandra chinensis induces vascular relaxation via activation of endothelial nitric oxide synthase.

    Science.gov (United States)

    Park, Ji Young; Choi, Young Whan; Yun, Jung Wook; Bae, Jin Ung; Seo, Kyo Won; Lee, Seung Jin; Park, So Youn; Kim, Chi Dae

    2012-01-01

    Gomisin J (GJ) is a lignan contained in Schisandra chinensis (SC) which is a well-known medicinal herb for improvement of cardiovascular symptoms in Korean. Thus, the present study examined the vascular effects of GJ, and also determined the mechanisms involved. Exposure of rat thoracic aorta to GJ (1-30μg/ml) resulted in a concentration-dependent vasorelaxation, which was more prominent in the endothelium (ED)-intact aorta. ED-dependent relaxation induced by GJ was markedly attenuated by pretreatment with L-NAME, a nitric oxide synthase (NOS) inhibitor. In the intact endothelial cells of rat thoracic aorta, GJ also enhanced nitric oxide (NO) production. In studies using human coronary artery endothelial cells, GJ enhanced phosphorylation of endothelial NOS (eNOS) at Ser(1177) with increased cytosolic translocation of eNOS, and subsequently increased NO production. These effects of GJ were attenuated not only by calcium chelators including EGTA and BAPTA-AM, but also by LY294002, a PI3K/Akt inhibitor, indicating calcium- and PI3K/Akt-dependent activation of eNOS by GJ. Moreover, the levels of intracellular calcium were increased immediately after GJ administration, but Akt phosphorylation was started to increase at 20min of GJ treatment. Based on these results with the facts that ED-dependent relaxation occurred rapidly after GJ treatment, it was suggested that the ED-dependent vasorelaxant effects of GJ were mediated mainly by calcium-dependent activation of eNOS with subsequent production of endothelial NO.

  3. A Metronidazole-Resistant Isolate of Blastocystis spp. Is Susceptible to Nitric Oxide and Downregulates Intestinal Epithelial Inducible Nitric Oxide Synthase by a Novel Parasite Survival Mechanism ▿

    Science.gov (United States)

    Mirza, Haris; Wu, Zhaona; Kidwai, Fahad; Tan, Kevin S. W.

    2011-01-01

    Blastocystis, one of the most common parasites colonizing the human intestine, is an extracellular, noninvasive, luminal protozoan with controversial pathogenesis. Blastocystis infections can be asymptomatic or cause intestinal symptoms of vomiting, diarrhea, and abdominal pain. Although chronic infections are frequently reported, Blastocystis infections have also been reported to be self-limiting in immunocompetent patients. Characterizing the host innate response to Blastocystis would lead to a better understanding of the parasite's pathogenesis. Intestinal epithelial cells produce nitric oxide (NO), primarily on the apical side, in order to target luminal pathogens. In this study, we show that NO production by intestinal cells may be a host defense mechanism against Blastocystis. Two clinically relevant isolates of Blastocystis, ST-7 (B) and ST-4 (WR-1), were found to be susceptible to a range of NO donors. ST-7 (B), a metronidazole-resistant isolate, was found to be more sensitive to nitrosative stress. Using the Caco-2 model of human intestinal epithelium, Blastocystis ST-7 (B) but not ST-4 (WR-1) exhibited dose-dependent inhibition of Caco-2 NO production, and this was associated with downregulation of inducible nitric oxide synthase (iNOS). Despite its higher susceptibility to NO, Blastocystis ST-7 (B) may have evolved unique strategies to evade this potential host defense by depressing host NO production. This is the first study to highlight a strain-to-strain variation in the ability of Blastocystis to evade the host antiparasitic NO response. PMID:21930763

  4. Role of Polymorphisms of Inducible Nitric Oxide Synthase and Endothelial Nitric Oxide Synthase in Idiopathic Environmental Intolerances

    Directory of Open Access Journals (Sweden)

    Chiara De Luca

    2015-01-01

    Full Text Available Oxidative stress and inflammation play a pathogenetic role in idiopathic environmental intolerances (IEI, namely, multiple chemical sensitivity (MCS, fibromyalgia (FM, and chronic fatigue syndrome (CFS. Given the reported association of nitric oxide synthase (NOS gene polymorphisms with inflammatory disorders, we aimed to investigate the distribution of NOS2A −2.5 kb (CCTTTn as well as Ser608Leu and NOS3 −786T>C variants and their correlation with nitrite/nitrate levels, in a study cohort including 170 MCS, 108 suspected MCS (SMCS, 89 FM/CFS, and 196 healthy subjects. Patients and controls had similar distributions of NOS2A Ser608Leu and NOS3 −786T>C polymorphisms. Interestingly, the NOS3 −786TT genotype was associated with increased nitrite/nitrate levels only in IEI patients. We also found that the NOS2A −2.5 kb (CCTTT11 allele represents a genetic determinant for FM/CFS, and the (CCTTT16 allele discriminates MCS from SMCS patients. Instead, the (CCTTT8 allele reduces by three-, six-, and tenfold, respectively, the risk for MCS, SMCS, and FM/CFS. Moreover, a short number of (CCTTT repeats is associated with higher concentrations of nitrites/nitrates. Here, we first demonstrate that NOS3 −786T>C variant affects nitrite/nitrate levels in IEI patients and that screening for NOS2A −2.5 kb (CCTTTn polymorphism may be useful for differential diagnosis of various IEI.

  5. Mepivacaine-induced contraction is attenuated by endothelial nitric oxide release in isolated rat aorta.

    Science.gov (United States)

    Sung, Hui-Jin; Choi, Mun-Jeoung; Ok, Seong-Ho; Lee, Soo Hee; Hwang, Il Jeong; Kim, Hee Sook; Chang, Ki Churl; Shin, Il-Woo; Lee, Heon-Keun; Park, Kyeong-Eon; Chung, Young-Kyun; Sohn, Ju-Tae

    2012-07-01

    Mepivacaine is an aminoamide-linked local anesthetic with an intermediate duration that intrinsically produces vasoconstriction both in vivo and in vitro. The aims of this in-vitro study were to examine the direct effect of mepivacaine in isolated rat aortic rings and to determine the associated cellular mechanism with a particular focus on endothelium-derived vasodilators, which modulate vascular tone. In the aortic rings with or without endothelium, cumulative mepivacaine concentration-response curves were generated in the presence or absence of the following antagonists: N(ω)-nitro-L-arginine methyl ester [L-NAME], indomethacin, fluconazole, methylene blue, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one [ODQ], verapamil, and calcium-free Krebs solution. Mepivacaine produced vasoconstriction at low concentrations (1 × 10(-3) and 3 × 10(-3) mol/L) followed by vasodilation at a high concentration (1 × 10(-2) mol/L). The mepivacaine-induced contraction was higher in endothelium-denuded aortae than in endothelium-intact aortae. Pretreatment with L-NAME, ODQ, and methylene blue enhanced mepivacaine-induced contraction in the endothelium-intact rings, whereas fluconazole had no effect. Indomethacin slightly attenuated mepivacaine-induced contraction, whereas verapamil and calcium-free Krebs solution more strongly attenuated this contraction. The vasoconstriction induced by mepivacaine is attenuated mainly by the endothelial nitric oxide - cyclic guanosine monophosphate pathway. In addition, mepivacaine-induced contraction involves cyclooxygenase pathway activation and extracellular calcium influx via voltage-operated calcium channels.

  6. Drug-induced liver injury: Is it somehow foreseeable?

    Institute of Scientific and Technical Information of China (English)

    Giovanni Tarantino; Matteo Nicola Dario Di Minno; Domenico Capone

    2009-01-01

    The classic view on the pathogenesis of drug-induced liver injury is that the so-called parent compounds are made hepatotoxic by metabolism (formation of neosubstances that react abnormally), mainly by cytochromes -450 (CYP), with further pathways, such as mitochondrial dysfunction and apoptosis, also playing a role. Risk factors for drug-induced liver injury include concomitant hepatic diseases, age and genetic polymorphisms of CYP. However, some susceptibility can today be predicted before drug administration, working on the common substrate, by phenotyping and genotyping studies and by taking in consideration patients' health status. Physicians should always think of this adverse effect in the absence of other clear hepatic disease. Ethical and legal problems towards operators in the health care system are always matters to consider.

  7. Inducible nitric oxide synthase expression and cardiomyocyte dysfunction during sustained moderate ischemia in pigs.

    Science.gov (United States)

    Heinzel, Frank R; Gres, Petra; Boengler, Kerstin; Duschin, Alexej; Konietzka, Ina; Rassaf, Tienush; Snedovskaya, Julia; Meyer, Stephanie; Skyschally, Andreas; Kelm, Malte; Heusch, Gerd; Schulz, Rainer

    2008-11-07

    In acute myocardial ischemia, regional blood flow and function are proportionally reduced. With prolongation of ischemia, function further declines at unchanged blood flow. We studied the involvement of an inflammatory signal cascade in such progressive dysfunction and whether dysfunction is intrinsic to cardiomyocytes. In 10 pigs, ischemia was induced by adjusting inflow into the cannulated left anterior coronary artery to reduce coronary arterial pressure to 45 mm Hg (ISCH); 4 pigs received the inducible nitric oxide synthase (iNOS) inhibitors aminoguanidine or L-N(6)-(1-iminoethyl)-lysine during ISCH (ISCH+iNOS-Inhib); 6 pigs served as controls (SHAM). Anterior (AW) and posterior (PW) systolic wall thickening (sonomicrometry) were measured. After 6 hours, nitric oxide (NO) synthase (NOS) protein expression, NOS activity, and NO metabolites (nitrite/nitrate/nitroso species) were quantified in biopsies isolated from AW and PW. Cardiomyocyte shortening and intracellular calcium (Indo-1 acetoxymethyl ester) were measured without and with the NOS substrate L-arginine (100 micromol/L). In ISCH, AW wall thickening decreased from 42+/-4% (baseline) to 16+/-3% (6 hours). Wall thickening remained unchanged in ISCH-PW and SHAM-AW/PW. NOS2 (iNOS) protein expression and activity, but not NOS3 (endothelial NO synthase), were increased in ISCH-AW and ISCH-PW. iNOS expression correlated with increased nitrite contents. Cardiomyocyte shortening was reduced in ISCH-AW versus SHAM-AW (4.4+/-0.3% versus 5.6+/-0.3%). L-Arginine reduced cardiomyocyte shortening further in ISCH-AW (to 2.8+/-0.2%) and ISCH-PW (3.4+/-0.4% versus 5.4+/-0.4%) but not in SHAM or in ISCH+iNOS-Inhib; intracellular [Ca(2+)] remained unchanged. With L-arginine, in vitro AW cardiomyocyte shortening correlated with in vivo AW wall thickening (r=0.72). In conclusion, sustained regional ischemia induces myocardial iNOS expression in pigs, which contributes to contractile dysfunction at the cardiomyocyte level.

  8. Significance of liver biopsy for the evaluation of methotrexate-induced liver damage in patients with rheumatoid arthritis.

    Science.gov (United States)

    Osuga, Tatsuya; Ikura, Yoshihiro; Kadota, Chikara; Hirano, Seiichi; Iwai, Yasuhiro; Hayakumo, Takanobu

    2015-01-01

    It is well recognized that long-term administration of methotrexate (MTX) in patients with rheumatoid arthritis (RA) can induce liver fibrosis via a steatohepatitis-like inflammatory process. Several non-invasive tests have been investigated as alternatives to liver biopsy, which is, however, still recognized as a final diagnostic modality to detect the MTX-induced liver damage. To clarify whether there is a significant discrepancy between clinical estimations and pathologic findings of this hepatic condition, we performed a following comparative study. Four RA patients (4 women, age 67-80 yr) with MTX-induced liver damage were reviewed. The severity of hepatic damage estimated clinically was compared with histopathologic findings. Consequently, the liver biopsies showed the relatively earlier stages of and milder degrees of hepatic damages than the clinical estimations. The histopathologic findings were more reliable and useful than any other clinical examinations, to plan and modify the treatment strategies, especially in cases of liver damages with multiple etiologies besides MTX. These findings suggest that liver biopsy is an unavoidable examination to assess precisely MTX-induced liver damage. Non-invasive tests may be useful to monitor the hepatic condition of RA patients receiving MTX but do not constitute an acceptable alternative to liver biopsy.

  9. Propylthiouracil-induced liver failure and artificial liver support systems: a case report and review of the literature

    Science.gov (United States)

    Wu, Dong-Bo; Chen, En-Qiang; Bai, Lang; Tang, Hong

    2017-01-01

    Background Antithyroid drugs carry a potential risk of hepatotoxicity. Propylthiouracil (PTU) is commonly prescribed for patients with hyperthyroidism. PTU, however, can induce liver injury, ranging from mild asymptomatic elevation of aminotransferases to acute liver failure (ALF). Case presentation This case reports on a 16-year-old Chinese girl with hyperthyroidism, who was admitted to our hospital for jaundice, nausea, and fatigue associated with severe hyperbilirubinemia and coagulopathy. She had been prescribed PTU 5 months earlier. There was no history of hypersensitivity to drugs, viral liver diseases, blood transfusion, or surgery. On the basis of her symptoms and the clinical data, she was diagnosed with PTU-induced ALF. Due to the limited number of available donor organs for liver transplantation, she was started on treatment with artificial liver support system (ALSS). After four sessions of ALSS, her clinical signs and symptoms were found to be markedly improved, and she was discharged 25 days after admission. Four months later, her liver function normalized. Conclusion Although PTU-induced liver failure is rare in clinical practice, liver function should be appropriately monitored during treatment with PTU. PTU-induced ALF in this patient was successfully managed with an ALSS, suggesting that the latter may be an alternative to liver transplantation. PMID:28138249

  10. Cyclic Stretch Induces Inducible Nitric Oxide Synthase and Soluble Guanylate Cyclase in Pulmonary Artery Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Kathryn N. Farrow

    2013-02-01

    Full Text Available In the pulmonary vasculature, mechanical forces such as cyclic stretch induce changes in vascular signaling, tone and remodeling. Nitric oxide is a potent regulator of soluble guanylate cyclase (sGC, which drives cGMP production, causing vasorelaxation. Pulmonary artery smooth muscle cells (PASMCs express inducible nitric oxide synthase (iNOS, and while iNOS expression increases during late gestation, little is known about how cyclic stretch impacts this pathway. In this study, PASMC were subjected to cyclic stretch of 20% amplitude and frequency of 1 Hz for 24 h and compared to control cells maintained under static conditions. Cyclic stretch significantly increased cytosolic oxidative stress as compared to static cells (62.9 ± 5.9% vs. 33.3 ± 5.7% maximal oxidation, as measured by the intracellular redox sensor roGFP. Cyclic stretch also increased sGCβ protein expression (2.5 ± 0.9-fold, sGC activity (1.5 ± 0.2-fold and cGMP levels (1.8 ± 0.2-fold, as well as iNOS mRNA and protein expression (3.0 ± 0.9 and 2.6 ± 0.7-fold, respectively relative to control cells. An antioxidant, recombinant human superoxide dismutase (rhSOD, significantly decreased stretch-induced cytosolic oxidative stress, but did not block stretch-induced sGC activity. Inhibition of iNOS with 1400 W or an iNOS-specific siRNA inhibited stretch-induced sGC activity by 30% and 68% respectively vs. static controls. In conclusion, cyclic stretch increases sGC expression and activity in an iNOS-dependent manner in PASMC from fetal lambs. The mechanism that produces iNOS and sGC upregulation is not yet known, but we speculate these effects represent an early compensatory mechanism to counteract the effects of stretch-induced oxidative stress. A better understanding of the interplay between these two distinct pathways could provide key insights into future avenues to treat infants with pulmonary hypertension.

  11. Nitric oxide-mediated bystander signal transduction induced by heavy-ion microbeam irradiation

    Science.gov (United States)

    Tomita, Masanori; Matsumoto, Hideki; Funayama, Tomoo; Yokota, Yuichiro; Otsuka, Kensuke; Maeda, Munetoshi; Kobayashi, Yasuhiko

    2015-07-01

    In general, a radiation-induced bystander response is known to be a cellular response induced in non-irradiated cells after receiving bystander signaling factors released from directly irradiated cells within a cell population. Bystander responses induced by high-linear energy transfer (LET) heavy ions at low fluence are an important health problem for astronauts in space. Bystander responses are mediated via physical cell-cell contact, such as gap-junction intercellular communication (GJIC) and/or diffusive factors released into the medium in cell culture conditions. Nitric oxide (NO) is a well-known major initiator/mediator of intercellular signaling within culture medium during bystander responses. In this study, we investigated the NO-mediated bystander signal transduction induced by high-LET argon (Ar)-ion microbeam irradiation of normal human fibroblasts. Foci formation by DNA double-strand break repair proteins was induced in non-irradiated cells, which were co-cultured with those irradiated by high-LET Ar-ion microbeams in the same culture plate. Foci formation was suppressed significantly by pretreatment with an NO scavenger. Furthermore, NO-mediated reproductive cell death was also induced in bystander cells. Phosphorylation of NF-κB and Akt were induced during NO-mediated bystander signaling in the irradiated and bystander cells. However, the activation of these proteins depended on the incubation time after irradiation. The accumulation of cyclooxygenase-2 (COX-2), a downstream target of NO and NF-κB, was observed in the bystander cells 6 h after irradiation but not in the directly irradiated cells. Our findings suggest that Akt- and NF-κB-dependent signaling pathways involving COX-2 play important roles in NO-mediated high-LET heavy-ion-induced bystander responses. In addition, COX-2 may be used as a molecular marker of high-LET heavy-ion-induced bystander cells to distinguish them from directly irradiated cells, although this may depend on the time

  12. Nitric oxide synthase inhibition delays low-frequency stimulation-induced satellite cell activation in rat fast-twitch muscle.

    Science.gov (United States)

    Martins, Karen J B; MacLean, Ian; Murdoch, Gordon K; Dixon, Walter T; Putman, Charles T

    2011-12-01

    This study examined the effect of nitric oxide synthase (NOS) inhibition via N(ω)-nitro-l-arginine methyl ester (l-NAME) administration on low-frequency stimulation-induced satellite cell (SC) activation in rat skeletal muscle. l-NAME only delayed stimulation-induced increases in SC activity. Also, stimulation-induced increases in hepatocyte growth factor (HGF) mRNA and protein expression were only abrogated at the mRNA level in l-NAME-treated animals. Therefore, early stimulation-induced SC activation appears to be NOS-dependent, while continued activation may involve NOS-independent HGF translational control mechanisms.

  13. Caspase-2 deficiency accelerates chemically induced liver cancer in mice.

    Science.gov (United States)

    Shalini, S; Nikolic, A; Wilson, C H; Puccini, J; Sladojevic, N; Finnie, J; Dorstyn, L; Kumar, S

    2016-10-01

    Aberrant cell death/survival has a critical role in the development of hepatocellular carcinoma (HCC). Caspase-2, a cell death protease, limits oxidative stress and chromosomal instability. To study its role in reactive oxygen species (ROS) and DNA damage-induced liver cancer, we assessed diethylnitrosamine (DEN)-mediated tumour development in caspase-2-deficient (Casp2(-/-)) mice. Following DEN injection in young animals, tumour development was monitored for 10 months. We found that DEN-treated Casp2(-/-) mice have dramatically elevated tumour burden and accelerated tumour progression with increased incidence of HCC, accompanied by higher oxidative damage and inflammation. Furthermore, following acute DEN injection, liver injury, DNA damage, inflammatory cytokine release and hepatocyte proliferation were enhanced in mice lacking caspase-2. Our study demonstrates for the first time that caspase-2 limits the progression of tumourigenesis induced by an ROS producing and DNA damaging reagent. Our findings suggest that after initial DEN-induced DNA damage, caspase-2 may remove aberrant cells to limit liver damage and disease progression. We propose that Casp2(-/-) mice, which are more susceptible to genomic instability, are limited in their ability to respond to DNA damage and thus carry more damaged cells resulting in accelerated tumourigenesis.

  14. Nitric oxide synthase inhibition ameliorates nicotine-induced sperm function decline in male rats

    Institute of Scientific and Technical Information of China (English)

    IP Oyeyipo; Y Raji; AdeyomboF Bolarinwa

    2015-01-01

    Objective:To evaluate the effects of inhibiting nitric oxide synthase as a means of intervention in nicotine-induced infertility in male rats.Methods:Forty-eight male and thirty female Wistar rats (180-200 g) were randomly assigned to six groups and treated orally for 30 days with saline (control), nicotine (0.5 mg/kg, 1.0 mg/kg) with or without NG Nitro-L-Arginine Methyl Ester (L- NAME, 50 mg/kg). Treated male rats were cohabited with untreated females in ratio 1:2 for fertility studies. Sperm analysis was done by microscopy. Results:There was a significant decrease in the epididymal sperm motility and count after nicotine treatment. However, the percentage of abnormality significantly increased in nicotine treatment groups. Fertility studies revealed that nicotine reduced libido in male rats and decreased litter weight and number delivered by the untreated female during the experiments. Co-treatment with L-NAME effectively reversed the nicotine-mediated alterations in the sperm functional parameters, fertility indexes and hormone when compared to nicotine only.Conclusion: Taken together, the present data indicate the abilities of L-NAME to ameliorate nicotine-induced spermatotoxic effects in male rats via a mechanism dependent on the circulating testosterone level.

  15. Nitric oxide suppresses NLRP3 inflammasome activation and protects against LPS-induced septic shock

    Institute of Scientific and Technical Information of China (English)

    Kairui Mao; Shuzhen Chen; Mingkuan Chen; Yonglei Ma; Yan Wang; Bo Huang; Zhengyu He

    2013-01-01

    Inflammasomes are multi-protein complexes that trigger the activation of caspase-1 and the maturation of interleukin-1β (IL-1β),yet the regulation of these complexes remains poorly characterized.Here we show that nitric oxide (NO) inhibited the NLRP3-mediated ASC pyroptosome formation,caspase-1 activation and IL-1β secretion in myeloid cells from both mice and humans.Meanwhile,endogenous NO derived from iNOS (inducible form of NO synthase) also negatively regulated NLRP3 inflammasome activation.Depletion of iNOS resulted in increased accumulation of dysfunctional mitochondria in response to LPS and ATP,which was responsible for the increased IL-1βproduction and caspase-1 activation,iNOS deficiency or pharmacological inhibition of NO production enhanced NL-RP3-dependent cytokine production in vivo,thus increasing mortality from LPS-induced sepsis in mice,which was prevented by NLRP3 deficiency.Our results thus identify NO as a critical negative regulator of the NLRP3 inflammasome via the stabilization of mitochondria.This study has important implications for the design of new strategies to control NLRP3-related diseases.

  16. Oxidative stress and nitric oxide in rats with alcohol-induced acute pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Gülnur Andican; Remisa Gelisgen; Gülden Burcak; Ethem Unal; Osman Baran Tortum; Tayfun Karahasanoglu

    2005-01-01

    AIM: Oxygen free radical mediated tissue damage is well established in pathogenesis of acute pancreatitis (AP).Whether nitric oxide (NO) plays a deleterious or a protective role is unknown. In alcohol-induced AP, we studied NO, lipooxidative damage and glutathione in pancreas, lung and circulation.METHODS: AP was induced in rats (n = 25) by injection of ethyl alcohol into the common biliary duct. A sham laparatomy was performed in controls (n = 15). After 24 h the animals were killed, blood and tissue sampling were done.RESULTS: Histopathologic evidence confirmed the development of AP. Marked changes were observed in the pulmonary tissue. Compared with controls, the AP group displayed higher values for NO metabolites in pancreas and lungs, and thiobarbituric acid reactive substances in circulation. Glutathione was lower in pancreas and in circulation. Glutathione and NO were positively correlated in pancreas and lungs of controls but negatively correlated in circulation of experimental group. In the experimental group, plasma thiobarbituric acid reactive substances were negatively correlated with pancreas thiobarbituric acid reactive substances but positively correlated with pancreas NO.CONCLUSION: NO increases in both pancreas and lungs in AP and NO contributes to the pathogenesis of AP under oxidative stress.

  17. Nitric oxide, polyamines and Cd-induced phytotoxicity in wheat roots.

    Science.gov (United States)

    Groppa, M D; Rosales, E P; Iannone, M F; Benavides, M P

    2008-10-01

    To further explore the biochemical basis of Cd toxicity in developing wheat seedlings, we studied the possible role of nitric oxide (NO) and polyamines as signaling molecules involved in metal-induced root growth inhibition. When used at 0.1 mM, sodium nitroprusside, a NO-releasing compound, inhibited root growth to a similar extent as Cd and enhanced the polyamine contents as Cd also did. Putrescine and spermidine treatments caused significant decreases in root growth with spermine giving the greatest level of inhibition (77% reduction). The simultaneous addition of Cd and inhibitors of putrescine biosynthesis (DFMA and DFMO) prevented increases in putrescine levels but did not restore normal root growth. NO content, as evidenced by the fluorescent probe DAF-FM diacetate, was found to be significantly increased in the roots of both Cd and polyamine treated plants, especially in those exposed to spermine. The effect was specific for NO since the NO scavenger cPTIO almost suppressed the fluorescent signal. Concerning the oxidative status of the root system, only Cd and spermine enhanced lipid peroxidation in roots. At the same time, all treatments led to a significant increase in levels of the non-enzymatic antioxidant defense glutathione. Our results strongly suggest that Cd and spermine treatments induce NO formation in wheat roots which, in turn, is involved in root growth inhibition.

  18. Nitric oxide mitigates arsenic-induced oxidative stress and genotoxicity in Vicia faba L.

    Science.gov (United States)

    Shukla, Pratiksha; Singh, A K

    2015-09-01

    The protective effects of nitric oxide (NO) against arsenic (As)-induced structural disturbances in Vicia faba have been investigated. As treatment (0.25, 0.50, and 1 mM) resulted in a declined growth of V. faba seedlings. Arsenic treatment stimulates the activity of SOD and CAT while the activities of APX and GST content were decreased. The oxidative stress markers such as superoxide radical, hydrogen peroxide and malondialdehyde (lipid peroxidation) contents were enhanced by As. Overall results revealed that significant accumulation of As suppressed growth, photosynthesis, antioxidant enzymes (SOD, CAT, APX, and GST activity), mitotic index, and induction of different chromosomal abnormalities, hence led to oxidative stress. The concentration of SNP (0.02 mM) was very effective in counteracting the adverse effect of As toxicity. These abnormalities use partially or fully reversed by a simultaneous application of As and NO donor and sodium nitroprusside and has an ameliorating effect against As-induced oxidative stress and genotoxicity in V. faba roots.

  19. Involvement of Nitric Oxide in a Rat Model of Carrageenin-Induced Pleurisy

    Directory of Open Access Journals (Sweden)

    Masahiro Iwata

    2010-01-01

    Full Text Available Some evidence indicates that nitric oxide (NO contributes to inflammation, while other evidence supports the opposite conclusion. To clarify the role of NO in inflammation, we studied carrageenin-induced pleurisy in rats treated with an NO donor (NOC-18, a substrate for NO formation (L-arginine, and/or an NO synthase inhibitor (S-(2-aminoethyl isothiourea or NG-nitro-L-arginine. We assessed inflammatory cell migration, nitrite/nitrate values, lipid peroxidation and pro-inflammatory mediators. NOC-18 and L-arginine reduced the migration of inflammatory cells and edema, lowered oxidative stress, and normalized antioxidant enzyme activities. NO synthase inhibitors increased the exudate formation and inflammatory cell number, contributed to oxidative stress, induced an oxidant/antioxidant imbalance by maintaining high O−2, and enhanced the production of pro-inflammatory mediators. L-arginine and NOC-18 reversed the proinflammatory effects of NO synthase inhibitors, perhaps by reducing the expression of adhesion molecules on endothelial cells. Thus, our results indicate that NO is involved in blunting—not enhancing—the inflammatory response.

  20. Activation of hypothalamic neuronal nitric oxide synthase in lithium-induced diabetes insipidus rats.

    Science.gov (United States)

    Anai, H; Ueta, Y; Serino, R; Nomura, M; Nakashima, Y; Yamashita, H

    2001-02-01

    The expression of the neuronal nitric oxide synthase (nNOS) gene in the paraventricular (PVN) and supraoptic nuclei (SON) in rats with lithium (Li)-induced polyuria was examined by using in situ hybridization histochemistry. The state of the thyroid axis in these rats was also examined by in situ hybridization histochemistry for thyrotropin-releasing hormone (TRH) and thyroid-stimulating hormone (TSH) mRNAs and radioimmunoassay for circulating thyroid hormones. Adult male Wistar rats consuming a diet that contained LiCl (60 mmol/kg) for 4 weeks developed remarkable polyuria. The urine in the Li-treated rats was hypotonic and had a large volume and low ionic concentration. The nNOS mRNA in the PVN and SON was significantly increased in the Li-treated rats in comparison with that in control. The increased levels of the nNOS mRNA in the PVN and SON were confirmed by NADPH-diaphorase histochemical staining. There were no differences of TRH mRNA in the PVN, TSH mRNA in the anterior pituitary and plasma concentrations of free T3 and free T4 between Li-treated rats and control rats. These results suggest that Li-induced diabetes insipidus may activate nNOS in the PVN and SON without change of the thyroid axis.

  1. Proinflammatory role of inducible nitric oxide synthase in acute hyperoxic lung injury

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    Kupatt Christian

    2004-09-01

    Full Text Available Abstract Background Hyperoxic exposures are often found in clinical settings of respiratory insufficient patients, although oxygen therapy (>50% O2 can result in the development of acute hyperoxic lung injury within a few days. Upon hyperoxic exposure, the inducible nitric oxide synthase (iNOS is activated by a variety of proinflammatory cytokines both in vitro and in vivo. In the present study, we used a murine hyperoxic model to evaluate the effects of iNOS deficiency on the inflammatory response. Methods Wild-type and iNOS-deficient mice were exposed to normoxia, 60% O2 or >95% O2 for 72 h. Results Exposure to >95% O2 resulted in an increased iNOS mRNA and protein expression in the lungs from wild-type mice. No significant effects of iNOS deficiency on cell differential in bronchoalveolar lavage fluid were observed. However, hyperoxia induced a significant increase in total cell count, protein concentration, LDH activity, lipid peroxidation, and TNF-α concentration in the bronchoalveolar lavage fluid compared to iNOS knockout mice. Moreover, binding activity of NF-κB and AP-1 appeared to be higher in wild-type than in iNOS-deficient mice. Conclusion Taken together, our results provide evidence to suggest that iNOS plays a proinflammatory role in acute hyperoxic lung injury.

  2. Melatonin can attenuate ciprofloxacin induced nephrotoxicity: Involvement of nitric oxide and TNF-α.

    Science.gov (United States)

    Shaki, Fatemeh; Ashari, Sorour; Ahangar, Nematollah

    2016-12-01

    Ciprofloxacin is a synthetic broad-spectrum antimicrobial agent of fluoroquinolone family. The aim of our investigation was to evaluate the role of oxidative damage and inflammation in nephrotoxic potential of Ciprofloxacin and protective effects of melatonin against its nephrotoxicity in male Wistar rats. The animals were divided into six groups: Control, ciprofloxacin (100mg/kg/day, i.p), ciprofloxacin with three doses (2.5, 5 and 10mg/kg/day) of melatonin and a group which received ciprofloxacin (100mg/kg/day) plus vitamin E (100mg/kg/day) for 8 consecutive days. 24h after last injection, the animals were euthanized and kidney tissues were separated. Finally reactive oxygen species, glutathione content, lipid peroxidation, protein carbonyl, nitric oxide and TNF-α were evaluated. Also, pathological examination and measuring of kidney biochemical markers (BUN and Cr) were done. The administration of ciprofloxacin for 8days resulted in significant increase (Pciprofloxacin group by significantly (pciprofloxacin-induced nephrotoxicity that markedly inhibited by administration of melatonin. So, melatonin can be suggested for prevention of ciprofloxacin-induced nephrotoxicity. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  3. Suppression of endothelin-3-induced nitric oxide synthesis by triglyceride in human endothelial cells.

    Science.gov (United States)

    Minami, M; Yokokawa, K; Kohno, M; Yasunari, K; Yoshikawa, J

    1998-01-01

    Reduced endothelium-derived nitric oxide (NO) production characterizes several vascular diseases. This study examined the effect of triglyceride on NO production induced by endothelin-3 (ET-3) in cultured human umbilical vein endothelial cells. Triglyceride-rich human plasma obtained after a high-carbohydrate diet with white wine was used in an ex vivo study. The plasma triglyceride fraction was found to consist of large amounts of palmitic and oleic acids detected by gas-liquid chromatography. Therefore, the effect of synthetic tripalmitin and triolein emulsion on NO production was also examined. ET-3 stimulated NO and guanosine 3',5'-cyclic monophosphate production and increased cytosolic Ca2+ levels in the endothelial cells (ECs). After incubation of the ECs with the triglyceride-rich plasma for 2 h, these responses to ET-3 were ameliorated in a triglyceride concentration-dependent manner (50-200 mg/dl). A synthesized emulsion of tripalmitin (100 mg/dl) and triolein (100 mg/dl) also blunted the responses to ET-3. Neither endothelial constitutive NO synthase mRNA expression nor its protein level was affected by treatment with triglycerides. These results suggest that triglyceride suppresses ET-3-induced NO synthesis in human ECs by inhibiting cytosolic Ca2+ elevation.

  4. An Update on Drug-induced Liver Injury.

    Science.gov (United States)

    Devarbhavi, Harshad

    2012-09-01

    Idiosyncratic drug-induced liver injury (DILI) is an important cause of morbidity and mortality following drugs taken in therapeutic doses. Hepatotoxicity is a leading cause of attrition in drug development, or withdrawal or restricted use after marketing. No age is exempt although adults and the elderly are at increased risk. DILI spans the entire spectrum ranging from asymptomatic elevation in transaminases to severe disease such as acute hepatitis leading to acute liver failure. The liver specific Roussel Uclaf Causality Assessment Method is the most validated and extensively used for determining the likelihood that an implicated drug caused DILI. Asymptomatic elevation in liver tests must be differentiated from adaptation. Drugs producing DILI have a signature pattern although no single pattern is characteristic. Antimicrobial and central nervous system agents including antiepileptic drugs are the leading causes of DILI worldwide. In the absence of a diagnostic test or a biomarker, the diagnosis rests on the evidence of absence of competing causes such as acute viral hepatitis, autoimmune hepatitis and others. Recent studies show that antituberculosis drugs given for active or latent disease are still a major cause of drug-induced liver injury in India and the West respectively. Presence of jaundice signifies a severe disease and entails a worse outcome. The pathogenesis is unclear and is due to a mix of host, drug metabolite and environmental factors. Research has evolved from incriminating candidate genes to genome wide analysis studies. Immediate cessation of the drug is key to prevent or minimize progressive damage. Treatment is largely supportive. N-acetylcysteine is the antidote for paracetamol toxicity. Carnitine has been tried in valproate injury whereas steroids and ursodeoxycholic acid may be used in DILI associated with hypersensitivity or cholestatic features respectively. This article provides an overview of the epidemiology, the patterns of

  5. Nitric Oxide Potentiates Oligosaccharide-induced Artemisinin Production in Artemisia annua Hairy Roots

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The purpose of the present study was to characterize the generation of nitric oxide (NO) in Artemisia annua roots induced by an oligosaccharide elicitor (OE) from Fusarium oxysporum mycelium and the potentiation role of NO in the elicitation of artemisinin accumulation. The OE (0.3 mg total sugar/mL) induced a rapid production of NO in cultures, which exhibited a biphasic time course, reaching the first plateau within 1.5 h and the second within 8 h of OE treatment. Artemisinin content in 20-day-old hairy roots was increased from 0.7 mg/g dry wt to 1.3 mg/g dry wt by using the OE treatment for 4d. In the absence of OE, the NO donor sodium nitroprusside (SNP) at 10, 50 μM and 100 μM enhanced the growth of hairy roots, but had no effect on artemisinin synthesis. The combination of SNP with OE increased artemisinin content from 1.2 mg/g dry wt to 2.2 mg/g dry wt, whereas the maximum production of artemisinin in cultures was 28.5 mg/L, a twofold increase over the OE treatment alone. The effects of SNP on the OE-induced artemisinin were suppressed strongly by the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO). The results suggest that NO can strongly potentiate elicitor-induced artemisinin synthesis in A. annua hairy roots.

  6. Nitric oxide in central amygdala potentiates expression of conditioned withdrawal induced by morphine

    Directory of Open Access Journals (Sweden)

    Manizheh Karami

    2014-01-01

    Full Text Available Objective: The aim of this study was to evaluate if nitric oxide (NO in the central amygdala (CeA is involved in the expression of withdrawal aspects induced by morphine. Materials and Methods: Male Wistar rats (weighing 200-250 g were bilaterally cannulated in the CeA and conditioned to morphine using an unbiased paradigm. Morphine (2.5-10 mg/kg was subcutaneously injected once a day throughout the conditioning phase of the procedure. This phase also included 3-saline paired sessions. Naloxone (0.1-0.4 mg/kg, intraperitoneally [i.p.], an antagonist of opioid receptors, was administered i.p. 10 min prior to testing of morphine-induced withdrawal features. The NO precursor, L-arginine (0.3-3 μg/rat was intra-CeA injected prior to testing of naloxone response. To evaluate the involvement of NO system an inhibitor of NO synthase (NOS, N G -nitro-L-arginine methyl ester (L-NAME (0.3-3 μg/rat, was injected ahead of L-arginine. Control group received saline solely instead of drug. As a complementary study, the activation of NOS was studied by nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d. Results: Morphine induced a significant increase in wet dog shaking and grooming behaviors compared with controls. Injection of naloxone pre-testing of morphine response significantly reversed the response to morphine. However, pre-microinjection of L-arginine intra-CeA recovered the response to morphine. Injection of L-NAME intra-CeA ahead of L-arginine though had no effect behaviorally, but, inhibited the NOS which has been evidenced by NADPH-d. Conclusion: The present study shows that NO in the CeA potentiates the expression of conditioned withdrawal induced by morphine paired with naloxone.

  7. Integrins mediate mechanical compression-induced endothelium-dependent vasodilation through endothelial nitric oxide pathway.

    Science.gov (United States)

    Lu, Xiao; Kassab, Ghassan S

    2015-09-01

    Cardiac and skeletal muscle contraction lead to compression of intramuscular arterioles, which, in turn, leads to their vasodilation (a process that may enhance blood flow during muscle activity). Although endothelium-derived nitric oxide (NO) has been implicated in compression-induced vasodilation, the mechanism whereby arterial compression elicits NO production is unclear. We cannulated isolated swine (n = 39) myocardial (n = 69) and skeletal muscle (n = 60) arteriole segments and exposed them to cyclic transmural pressure generated by either intraluminal or extraluminal pressure pulses to simulate compression in contracting muscle. We found that the vasodilation elicited by internal or external pressure pulses was equivalent; moreover, vasodilation in response to pressure depended on changes in arteriole diameter. Agonist-induced endothelium-dependent and -independent vasodilation was used to verify endothelial and vascular smooth muscle cell viability. Vasodilation in response to cyclic changes in transmural pressure was smaller than that elicited by pharmacological activation of the NO signaling pathway. It was attenuated by inhibition of NO synthase and by mechanical removal of the endothelium. Stemming from previous observations that endothelial integrin is implicated in vasodilation in response to shear stress, we found that function-blocking integrin α5β1 or αvβ3 antibodies attenuated cyclic compression-induced vasodilation and NOx (NO(-)2 and NO(-)3) production, as did an RGD peptide that competitively inhibits ligand binding to some integrins. We therefore conclude that integrin plays a role in cyclic compression-induced endothelial NO production and thereby in the vasodilation of small arteries during cyclic transmural pressure loading.

  8. Nitric oxide mediates the stress response induced by diatom aldehydes in the sea urchin Paracentrotus lividus.

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    Giovanna Romano

    Full Text Available Diatoms are ubiquitous and abundant primary producers that have been traditionally considered as a beneficial food source for grazers and for the transfer of carbon through marine food webs. However, many diatom species produce polyunsaturated aldehydes that disrupt development in the offspring of grazers that feed on these unicellular algae. Here we provide evidence that production of the physiological messenger nitric oxide increases after treatment with the polyunsaturated aldehyde decadienal in embryos of the sea urchin Paracentrotus lividus. At high decadienal concentrations, nitric oxide mediates initial apoptotic events leading to loss of mitochondrial functionality through the generation of peroxynitrite. At low decadienal concentrations, nitric oxide contributes to the activation of hsp70 gene expression thereby protecting embryos against the toxic effects of this aldehyde. When nitric oxide levels were lowered by inhibiting nitric oxide synthase activity, the expression of hsp70 in swimming blastula decreased and the proportion of abnormal plutei increased. However, in later pluteus stages nitric oxide was no longer able to exert this protective function: hsp70 and nitric oxide synthase expression decreased with a consequent increase in the expression of caspase-8. Our findings that nitric oxide production increases rapidly in response to a toxic exogenous stimulus opens new perspectives on the possible role of this gas as an important messenger to environmental stress in sea urchins and for understanding the cellular mechanisms underlying toxicity during diatom blooms.

  9. Nitric oxide mediates the stress response induced by diatom aldehydes in the sea urchin Paracentrotus lividus.

    Science.gov (United States)

    Romano, Giovanna; Costantini, Maria; Buttino, Isabella; Ianora, Adrianna; Palumbo, Anna

    2011-01-01

    Diatoms are ubiquitous and abundant primary producers that have been traditionally considered as a beneficial food source for grazers and for the transfer of carbon through marine food webs. However, many diatom species produce polyunsaturated aldehydes that disrupt development in the offspring of grazers that feed on these unicellular algae. Here we provide evidence that production of the physiological messenger nitric oxide increases after treatment with the polyunsaturated aldehyde decadienal in embryos of the sea urchin Paracentrotus lividus. At high decadienal concentrations, nitric oxide mediates initial apoptotic events leading to loss of mitochondrial functionality through the generation of peroxynitrite. At low decadienal concentrations, nitric oxide contributes to the activation of hsp70 gene expression thereby protecting embryos against the toxic effects of this aldehyde. When nitric oxide levels were lowered by inhibiting nitric oxide synthase activity, the expression of hsp70 in swimming blastula decreased and the proportion of abnormal plutei increased. However, in later pluteus stages nitric oxide was no longer able to exert this protective function: hsp70 and nitric oxide synthase expression decreased with a consequent increase in the expression of caspase-8. Our findings that nitric oxide production increases rapidly in response to a toxic exogenous stimulus opens new perspectives on the possible role of this gas as an important messenger to environmental stress in sea urchins and for understanding the cellular mechanisms underlying toxicity during diatom blooms.

  10. Diabetic HDL-associated myristic acid inhibits acetylcholine-induced nitric oxide generation by preventing the association of endothelial nitric oxide synthase with calmodulin.

    Science.gov (United States)

    White, James; Guerin, Theresa; Swanson, Hollie; Post, Steven; Zhu, Haining; Gong, Ming; Liu, Jun; Everson, William V; Li, Xiang-An; Graf, Gregory A; Ballard, Hubert O; Ross, Stuart A; Smart, Eric J

    2008-01-01

    In the current study, we examined whether diabetes affected the ability of HDL to stimulate nitric oxide (NO) production. Using HDL isolated from both diabetic humans and diabetic mouse models, we found that female HDL no longer induced NO synthesis, despite containing equivalent amounts of estrogen as nondiabetic controls. Furthermore, HDL isolated from diabetic females and males prevented acetylcholine-induced stimulation of NO generation. Analyses of both the human and mouse diabetic HDL particles showed that the HDLs contained increased levels of myristic acid. To determine whether myristic acid associated with HDL particles was responsible for the decrease in NO generation, myristic acid was added to HDL isolated from nondiabetic humans and mice. Myristic acid-associated HDL inhibited the generation of NO in a dose-dependent manner. Importantly, diabetic HDL did not alter the levels of endothelial NO synthase or acetylcholine receptors associated with the cells. Surprisingly, diabetic HDL inhibited ionomycin-induced stimulation of NO production without affecting ionomycin-induced increases in intracellular calcium. Further analysis indicated that diabetic HDL prevented calmodulin from interacting with endothelial NO synthase (eNOS) but did not affect the activation of calmodulin kinase or calcium-independent mechanisms for stimulating eNOS. These studies are the first to show that a specific fatty acid associated with HDL inhibits the stimulation of NO generation. These findings have important implications regarding cardiovascular disease in diabetic patients.

  11. Propylthiouracil-induced liver failure and artificial liver support systems: a case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Wu DB

    2017-01-01

    Full Text Available Dong-Bo Wu,1,2 En-Qiang Chen,1,2 Lang Bai,1,2 Hong Tang1,2 1Center of Infectious Diseases, West China Hospital of Sichuan University, 2Division of Molecular Biology of Infectious Diseases, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, People’s Republic of China Background: Antithyroid drugs carry a potential risk of hepatotoxicity. Propylthiouracil (PTU is commonly prescribed for patients with hyperthyroidism. PTU, however, can induce liver injury, ranging from mild asymptomatic elevation of aminotransferases to acute liver failure (ALF.Case presentation: This case reports on a 16-year-old Chinese girl with hyperthyroidism, who was admitted to our hospital for jaundice, nausea, and fatigue associated with severe hyperbilirubinemia and coagulopathy. She had been prescribed PTU 5 months earlier. There was no history of hypersensitivity to drugs, viral liver diseases, blood transfusion, or surgery. On the basis of her symptoms and the clinical data, she was diagnosed with PTU-induced ALF. Due to the limited number of available donor organs for liver transplantation, she was started on treatment with artificial liver support system (ALSS. After four sessions of ALSS, her clinical signs and symptoms were found to be markedly improved, and she was discharged 25 days after admission. Four months later, her liver function normalized.Conclusion: Although PTU-induced liver failure is rare in clinical practice, liver function should be appropriately monitored during treatment with PTU. PTU-induced ALF in this patient was successfully managed with an ALSS, suggesting that the latter may be an alternative to liver transplantation. Keywords: propylthiouracil, liver injury, acute liver failure, artificial liver support systems 

  12. Psychosine-induced alterations in peroxisomes of Twitcher Mouse Liver

    Science.gov (United States)

    Contreras, Miguel Agustin; Haq, Ehtishamul; Uto, Takuhiro; Singh, Inderjit; Singh, Avtar Kaur

    2008-01-01

    Krabbe’s disease is a neuroinflammatory disorder in which galactosylsphingosine (psychosine) accumulates in nervous tissue. To gain insight into whether the psychosine-induced effects in nervous tissue extend to peripheral organs, we investigated the expression of cytokines and their effects on peroxisomal structure/function in twitcher mouse liver (animal model of Krabbe disease). Immunofluorescence analysis demonstrated TNF-α and IL-6 expression, which was confirmed by mRNAs quantitation. Despite the presence of TNF-α, lipidomic analysis did not indicate a significant decrease in sphingomyelin or an increase in ceramide fractions. Ultrastructural analysis of catalase-dependent staining of liver sections showed reduced reactivity without significant changes in peroxisomal contents. This observation was confirmed by assaying catalase activity and quantitation of its mRNA, both of which were found significantly decreased in twitcher mouse liver. Western blot analysis demonstrated a generalized reduction of peroxisomal matrix and membrane proteins. These observations indicate that twitcher mouse pathobiology extends to the liver, where the induction of TNF-α and IL-6 compromise peroxisomal structure and function. PMID:18602885

  13. Quercetin protection against ciprofloxacin induced liver damage in rats.

    Science.gov (United States)

    Taslidere, E; Dogan, Z; Elbe, H; Vardi, N; Cetin, A; Turkoz, Y

    2016-01-01

    Ciprofloxacin is a common, broad spectrum antibacterial agent; however, evidence is accumulating that ciprofloxacin may cause liver damage. Quercetin is a free radical scavenger and antioxidant. We investigated histological changes in hepatic tissue of rats caused by ciprofloxacin and the effects of quercetin on these changes using histochemical and biochemical methods. We divided 28 adult female Wistar albino rats into four equal groups: control, quercetin treated, ciprofloxacin treated, and ciprofloxacin + quercetin treated. At the end of the experiment, liver samples were processed for light microscopic examination and biochemical measurements. Sections were prepared and stained with hematoxylin and eosin, and a histopathologic damage score was calculated. The sections from the control group appeared normal. Hemorrhage, inflammatory cell infiltration and intracellular vacuolization were observed in the ciprofloxacin group. The histopathological findings were reduced in the group treated with quercetin. Significant differences were found between the control and ciprofloxacin groups, and between the ciprofloxacin and ciprofloxacin + quercetin groups. Quercetin administration reduced liver injury caused by ciprofloxacin in rats. We suggest that quercetin may be useful for preventing ciprofloxacin induced liver damage.

  14. Rapamycin Induces Heme Oxygenase-1 in Liver but Inhibits Bile Flow Recovery after Ischemia

    NARCIS (Netherlands)

    Kist, Alwine; Wakkie, Joris; Madu, Max; Versteeg, Ruth; ten Berge, Judith; Nikolic, Andrej; Nieuwenhuijs, Vincent B.; Porte, Robert J.; Padbury, Robert T. A.; Barritt, Greg J.

    2012-01-01

    Background/Aims. Rapamycin, which is employed in the management of patients undergoing liver surgery, induces the synthesis of heme oxygenase-1 (HO-1) in some non-liver cell types. The aim was to investigate whether rapamycin can induce HO-1 expression in the liver, and to test the effects of rapamy

  15. YC-1 potentiates cAMP-induced CREB activation and nitric oxide production in alveolar macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Tsong-Long, E-mail: htl@mail.cgu.edu.tw [Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan, Taiwan (China); Chinese Herbal Medicine Research Team, Healthy Aging Research Center, Chang Gung University, Kweishan, Taoyuan, Taiwan (China); Tang, Ming-Chi [Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan, Taiwan (China); Kuo, Liang-Mou [Department of General Surgery, Chang Gung Memorial Hospital at Chia-Yi, Taiwan (China); Chang, Wen-De; Chung, Pei-Jen; Chang, Ya-Wen; Fang, Yao-Ching [Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan, Taiwan (China)

    2012-04-15

    Alveolar macrophages play significant roles in the pathogenesis of several inflammatory lung diseases. Increases in exhaled nitric oxide (NO) are well documented to reflect disease severity in the airway. In this study, we investigated the effect of 3-(5′-hydroxymethyl-2′-furyl)-1-benzyl indazole (YC-1), a known activator of soluble guanylyl cyclase, on prostaglandin (PG)E{sub 1} (a stable PGE{sub 2} analogue) and forskolin (a adenylate cyclase activator) induced NO production and inducible NO synthase (iNOS) expression in rat alveolar macrophages (NR8383). YC-1 did not directly cause NO production or iNOS expression, but drastically potentiated PGE{sub 1}- or forskolin-induced NO production and iNOS expression in NR8383 alveolar macrophages. Combination treatment with YC-1 and PGE{sub 1} significantly increased phosphorylation of the cAMP response element-binding protein (CREB), but not nuclear factor (NF)-κB activation. The combined effect on NO production, iNOS expression, and CREB phosphorylation was reversed by a protein kinase (PK)A inhibitor (H89), suggesting that the potentiating functions were mediated through a cAMP/PKA signaling pathway. Consistent with this, cAMP analogues, but not the cGMP analogue, caused NO release, iNOS expression, and CREB activation. YC-1 treatment induced an increase in PGE{sub 1}-induced cAMP formation, which occurred through the inhibition of cAMP-specific phosphodiesterase (PDE) activity. Furthermore, the combination of rolipram (an inhibitor of PDE4), but not milronone (an inhibitor of PDE3), and PGE{sub 1} also triggered NO production and iNOS expression. In summary, YC-1 potentiates PGE{sub 1}-induced NO production and iNOS expression in alveolar macrophages through inhibition of cAMP PDE activity and activation of the cAMP/PKA/CREB signaling pathway. Highlights: ► YC-1 potentiated PGE1-induced iNOS expression in alveolar macrophages. ► The combination of YC-1 and PGE1 increased CREB but not NFκB activation.

  16. Nitric oxide mediates the fungal elicitor-induced Taxol biosynthesis of Taxus chinensis suspension cells through the reactive oxygen species-dependent and-independent signal pathways

    Institute of Scientific and Technical Information of China (English)

    XU Maojun; DONG Jufang

    2006-01-01

    Nitric oxide and reactive oxygen species are two important signal molecules that play key roles in plant defense responses. Nitric oxide generation and oxidative burst and accumulation of reactive oxygen species are the early reactions of Taxus chinensis suspension cells to fungal elicitor prepared from the cell walls of Penicillium citrinum. In order to investigate the relationship and/or interactions of nitric oxide and reactive oxygen species in the elicitor-induced Taxol biosynthesis of T. chinensis suspension cells, we treated the cells with nitric oxide specific scavenger 2-4-carboxyphenyl-4,4,5,5-tetra- methylimidazoline-1-oxyl-3-oxide (cPITO), nitric oxide synthase inhibitor S,S(-1,3-phenylene-bis(1,2-eth- anediyl)-bis-isothiourea (PBITU), membrane NAD(P) H oxidase inhibitor diphenylene iodonium (DPI), superoxide dismutases (SOD) and catalase. The results show that pretreatment of T. chinensis cells with cPITO and DPI inhibited not only the elicitor-induced nitric oxide biosynthesis and oxidative burst, but also the elicitor-induced Taxol production, suggesting that both nitric oxide and reactive oxygen species are involved in elicitor-induced Taxol biosynthesis. Furthermore, pretreatment of the cells with cPITO and PBITU suppressed the elicitor-induced oxidative burst, indicating that the oxidative burst might be dependent on NO. Application of nitric oxide via its donor sodium nitroprusside (SNP) triggered Taxol biosynthesis of T. chinensis cells. The nitric oxide-induced Taxol production was suppressed by DPI, showing that the oxidative burst is involved in NO-triggered Taxol biosynthesis. However, nitric oxide and the fungal elicitor induced Taxol biosynthesis even though the accumulation of reactive oxygen species wass completely abolished in T. chinensis cells. Our data show that nitric oxide may mediate the elicitor-induced Taxol biosynthesis of T. chinensis suspension cells through both reactive oxygen species-dependent and -independent signal

  17. Thiamethoxam induced mouse liver tumors and their relevance to humans. Part 1: mode of action studies in the mouse.

    Science.gov (United States)

    Green, Trevor; Toghill, Alison; Lee, Robert; Waechter, Felix; Weber, Edgar; Noakes, James

    2005-07-01

    Thiamethoxam, a neonicotinoid insecticide, which is not mutagenic either in vitro or in vivo, caused an increased incidence of liver tumors in mice when fed in the diet for 18 months at concentrations in the range 500 to 2500 ppm. A number of dietary studies of up to 50 weeks duration have been conducted in order to identify the mode of action for the development of the liver tumors seen at the end of the cancer bioassay. Both thiamethoxam and its major metabolites have been tested in these studies. Over the duration of a 50-week thiamethoxam dietary feeding study in mice, the earliest change, within one week, is a marked reduction (by up to 40%) in plasma cholesterol. This was followed 10 weeks later by evidence of liver toxicity including single cell necrosis and an increase in apoptosis. After 20 weeks there was a significant increase in hepatic cell replication rates. All of these changes persisted from the time they were first observed until the end of the study at 50 weeks. They occurred in a dose-dependent manner and were only observed at doses (500, 1250, 2500 ppm) where liver tumors were increased in the cancer bioassay. There was a clear no-effect level of 200 ppm. The changes seen in this study are consistent with the development of liver cancer in mice and form the basis of the mode of action. When the major metabolites of thiamethoxam, CGA322704, CGA265307, and CGA330050 were tested in dietary feeding studies of up to 20 weeks duration, only metabolite CGA330050 induced the same changes as those seen in the liver in the thiamethoxam feeding study. It was concluded that thiamethoxam is hepatotoxic and hepatocarcinogenic as a result of its metabolism to CGA330050. Metabolite CGA265307 was also shown to be an inhibitor of inducible nitric oxide synthase and to increase the hepatotoxicity of carbon tetrachloride. It is proposed that CGA265307, through its effects on nitric oxide synthase, exacerbates the toxicity of CGA330050 in thiamethoxam treated mice.

  18. Protective effects of C-phycocyanin on alcohol-induced acute liver injury in mice

    Science.gov (United States)

    Xia, Dong; Liu, Bing; Luan, Xiying; Sun, Junyan; Liu, Nana; Qin, Song; Du, Zhenning

    2016-03-01

    Excessive alcohol consumption leads to liver disease. Extensive evidence suggests that C-phycocyanin (C-PC), a chromophore phycocyanobilin derived from Spirulina platensis, exerts protective effects against chemical-induced organ damage. In this study, we investigated whether C-PC could protect against ethanol-induced acute liver injury. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), total cholesterol (CHOL), low-density lipoprotein (LDL), liver homogenate malondialdehyde (MDA), superoxide dismutase (SOD) content were measured, and pathological examination of liver sections were examined. C-PC showed obvious inhibitory effects on serum ALT, AST, TG, CHOL, LDL and MDA, and SOD content significantly increased in the liver. The structure of hepatic lobules was clear, liver sinus returned to normal, and liver cell cords were arranged in neat rows. Cloudiness, swelling, inflammatory cell infiltration and spotty necrosis of liver cells were significantly reduced. Therefore, C-PC can significantly protect against ethanol-induced acute liver injury.

  19. Involvement of nitric oxide in myotoxicity produced by diisopropylphosphorofluoridate (DFP)-induced muscle hyperactivity

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Ramesh C. [Toxicology Department, Breathitt Veterinary Center, Murray State University, PO Box 2000, Hopkinsville, KY 42240 (United States); Milatovic, Dejan [Department of Pathology, Medical Center North, Vanderbilt University, Nashville, Tennessee (United States); Dettbarn, Wolf-D. [Department of Pharmacology, Vanderbilt University, Nashville, Tennessee (United States)

    2002-12-01

    Oxidative stress, as determined by increased lipid peroxidation, has been implicated in the pathology of myotoxicity. As a model system to study the response of muscle to oxidative insults, we have studied the effects of diisopropylphosphorofluoridate (DFP)-induced muscle hyperactivity on levels of nitric oxide (NO) and energy metabolites in rat skeletal muscles. In in vivo experiments, citrulline levels as indicators of NO and NO synthase (NOS), and ATP and phosphocreatine (PCr) as indicators of mitochondrial dysfunction, were determined using HPLC methods 15 min, 30 min, 60 min, 2 h, and 24 h after intoxication. Within 15 min of DFP exposure, with onset of fasciculations, citrulline levels were significantly elevated in all three muscles [soleus, extensor digitorum longus (EDL), and diaphragm]. Maximum increases in citrulline (272-288%) were noted 60 min after DFP injection. At this time point, acetylcholinesterase activity was reduced by 90-96% (soleus < diaphragm < EDL). The levels of ATP and PCr were maximally reduced (30-43%), and total adenine nucleotides, and total creatine compounds showed declines. The findings revealed that the increase in NOS activity and NO was greater than the decrease of ATP and PCr. Since memantine (MEM) has been shown to reduce nerve and muscle hyperactivity, we have studied the possible protective effect of MEM on the DFP-induced biochemical changes. Pretreatment with MEM (18 mg/kg s.c.) and atropine sulfate (16 mg/kg s.c.), 60 min and 15 min, respectively, before DFP injection prevented the increase in citrulline and muscle hyperactivity and the decrease in ATP and PCr. These data suggest that free radical reactions by depleting high-energy phosphates may be initiating the cascade of events leading to myotoxicity during DFP-induced muscle hyperactivity. (orig.)

  20. Protective vascular and cardiac effects of inducible nitric oxide synthase in mice with hyperhomocysteinemia.

    Directory of Open Access Journals (Sweden)

    Sanjana Dayal

    Full Text Available Diet-induced hyperhomocysteinemia produces endothelial and cardiac dysfunction and promotes thrombosis through a mechanism proposed to involve oxidative stress. Inducible nitric oxide synthase (iNOS is upregulated in hyperhomocysteinemia and can generate superoxide. We therefore tested the hypothesis that iNOS mediates the adverse oxidative, vascular, thrombotic, and cardiac effects of hyperhomocysteinemia. Mice deficient in iNOS (Nos2-/- and their wild-type (Nos2+/+ littermates were fed a high methionine/low folate (HM/LF diet to induce mild hyperhomocysteinemia, with a 2-fold increase in plasma total homocysteine (P<0.001 vs. control diet. Hyperhomocysteinemic Nos2+/+ mice exhibited endothelial dysfunction in cerebral arterioles, with impaired dilatation to acetylcholine but not nitroprusside, and enhanced susceptibility to carotid artery thrombosis, with shortened times to occlusion following photochemical injury (P<0.05 vs. control diet. Nos2-/- mice had decreased rather than increased dilatation responses to acetylcholine (P<0.05 vs. Nos2+/+ mice. Nos2-/- mice fed control diet also exhibited shortened times to thrombotic occlusion (P<0.05 vs. Nos2+/+ mice, and iNOS deficiency failed to protect from endothelial dysfunction or accelerated thrombosis in mice with hyperhomocysteinemia. Deficiency of iNOS did not alter myocardial infarct size in mice fed the control diet but significantly increased infarct size and cardiac superoxide production in mice fed the HM/LF diet (P<0.05 vs. Nos2+/+ mice. These findings suggest that endogenous iNOS protects from, rather than exacerbates, endothelial dysfunction, thrombosis, and hyperhomocysteinemia-associated myocardial ischemia-reperfusion injury. In the setting of mild hyperhomocysteinemia, iNOS functions to blunt cardiac oxidative stress rather than functioning as a source of superoxide.

  1. The role of nitric oxide in saline-induced natriuresis and diuresis in rats.

    Science.gov (United States)

    Noonan, W T; Banks, R O

    1999-09-01

    This study was designed to determine to what extent nitric oxide (NO) mediates the natriuretic and diuretic responses to acute isotonic saline (0.9 gram % NaCl) volume expansion (SVE, 0.5 ml min-1 kg-1). Studies were performed on 49 pentobarbital anesthetized (65 mg/kg) female Sprague-Dawley rats with or without a NO synthase inhibitor, Nomega-nitro-L-arginine (LNA). Group 1 received saline at 27 microliter/min for 1 hr (baseline) and then SVE for 1 hr; Groups 2-4 received LNA at 10, 150, and 200 microgram kg-1 min-1, respectively, for 1 hr followed by LNA + SVE. To determine to what extent inhibition of NOS would reverse an ongoing SVE-induced natriuresis and diuresis, Group 5 was saline-volume-expanded for hours 1 and 2 whereas Group 6 was administered SVE during the first hour and then SVE + 150 microgram kg -1 min-1 LNA during the second hour. SVE caused a significant (P natriuresis or diuresis in these animals). Along these lines, there was a small but significant positive linear correlation coefficient (r = 0.41, P = 0.05) between sodium excretion values and corresponding MAP values in SVE control rats but not in Groups 3-4 during SVE (r = 0.28, P = 0.26). The current data demonstrate that 1) NO does not mediate SVE-induced hyperfiltration in the rat, 2) NO also does not mediate SVE-induced natriuresis or diuresis, and 3), consistent with other reports, NO appears to mediate pressure natriuresis and diuresis.

  2. Effects of nitric oxide on gastric ulceration induced by nicotine and cold-restraint stress

    Institute of Scientific and Technical Information of China (English)

    Bo-Sheng Qui; Qi-Bing Mei; Li Liu; Kam-Meng Tchou-Wong

    2004-01-01

    AIM: Stress induces gastric ulceration in human and experimental animals. People tend to smoke more cigarettes when under stress. Nitric oxide (NO) and nicotine have opposing effects on gastric integrity. The present study examined the possible therapeutic benefit of NO in nicotinetreated rats with stress-induced gastric ulceration.METHODS: Rats drank a nicotine solution while control rats drank tap water for 20 days. The alkoloid was then replaced by water with or without supplementation of isosorbide dinitrate (NO donor) for an additional 10 days. Isosorbide dinitrate was given twice shortly before experiments (acute)or three times daily by oral gavages for 10 days after the rats stopped drinking nicotine solution. At the end of experiments,ulcer index, gastric adhesion mucus content and MPO activity were measured and analysed.RESULTS: Nicotine treatment decreased gastric mucus content and intensified stress-induced gastric ulcer. A higher ulcer index persisted even after the rats stopped drinking nicotine solution for 10 days. Acute NO donor showed no benefit on both mucus and ulcer index in nicotine treatment or/and stress condition. Chronic NO donor treatment reversed the worsening action of nicotine in stomach. Stress increased gastric mucosal myeloperoxidase (MPO) activity, which was antagonized by chronic NO treatment. However, nicotine was unlikely to change mucosal MPO activity.CONCLUSION: The intensifying action of nicotine on stressinduced gastric ulceration persists for 10 days after cessation.Nicotine treatment significantly decreases gastric mucus content that can be restored by chronic NO donor treatment.The present study suggests that NO antagonizes the ulcerogenic action of nicotine through a cytoprotective way.

  3. Nitric oxide synthase 3 contributes to ventilator-induced lung injury

    Science.gov (United States)

    Vaporidi, Katerina; Francis, Roland C.; Bloch, Kenneth D.

    2010-01-01

    Nitric oxide synthase (NOS) depletion or inhibition reduces ventilator-induced lung injury (VILI), but the responsible mechanisms remain incompletely defined. The aim of this study was to elucidate the role of endothelial NOS, NOS3, in the pathogenesis of VILI in an in vivo mouse model. Wild-type and NOS3-deficient mice were ventilated with high-tidal volume (HVT; 40 ml/kg) for 4 h, with and without adding NO to the inhaled gas. Additional wild-type mice were pretreated with tetrahydrobiopterin and ascorbic acid, agents that can prevent NOS-generated superoxide production. Arterial blood gas tensions, histology, and lung mechanics were evaluated after 4 h of HVT ventilation. The concentration of protein, IgM, cytokines, malondialdehyde, and 8-isoprostane were measured in bronchoalveolar lavage fluid (BALF). Myeloperoxidase activity, total and oxidized glutathione levels, and NOS-derived superoxide production were measured in lung tissue homogenates. HVT ventilation induced VILI in wild-type mice, as reflected by decreased lung compliance, increased concentrations of protein and cytokines in BALF, and oxidative stress. All indices of VILI were ameliorated in NOS3-deficient mice. Augmenting pulmonary NO levels by breathing NO during mechanical ventilation did not increase lung injury in NOS3-deficient mice. HVT ventilation increased NOS-inhibitable superoxide production in lung extracts from wild-type mice but not in those from NOS3-deficient mice. Administration of tetrahydrobiopterin and ascorbic acid ameliorated VILI in wild-type mice. Our results indicate that NOS3 contributes to ventilator-induced lung injury via increased production of superoxide. PMID:20453164

  4. Red Sea Suberea mollis Sponge Extract Protects against CCl4-Induced Acute Liver Injury in Rats via an Antioxidant Mechanism

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    Aymn T. Abbas

    2014-01-01

    Full Text Available Recent studies have demonstrated that marine sponges and their active constituents exhibited several potential medical applications. This study aimed to evaluate the possible hepatoprotective role as well as the antioxidant effect of the Red Sea Suberea mollis sponge extract (SMSE on carbon tetrachloride- (CCl4- induced acute liver injury in rats. In vitro antioxidant activity of SMSE was evaluated by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH assay. Rats were orally administered three different concentrations (100, 200, and 400 mg/kg of SMSE and silymarin (100 mg/kg along with CCl4 (1 mL/kg, i.p., every 72 hr for 14 days. Plasma aspartate aminotransferase (AST, alanine aminotransferase (ALT, alkaline phosphatase (ALP, and total bilirubin were measured. Hepatic malondialdehyde (MDA, reduced glutathione (GSH, nitric oxide (NO, superoxide dismutase (SOD, glutathione peroxidase (GPx, and catalase (CAT were also measured. Liver specimens were histopathologically examined. SMSE showed strong scavenging activity against free radicals in DPPH assay. SMSE significantly reduced liver enzyme activities. Moreover, SMSE significantly reduced hepatic MDA formation. In addition, SMSE restored GSH, NO, SOD, GPx, and CAT. The histopathological results confirmed these findings. The results of this study suggested a potent protective effect of the SMSE against CCl4-induced hepatic injury. This may be due to its antioxidant and radical scavenging activity.

  5. Nitric oxide induces tyrosine nitration and release of cytochrome c preceding an increase of mitochondrial transmembrane potential in macrophages.

    Science.gov (United States)

    Hortelano, S; Alvarez, A M; Boscá, L

    1999-12-01

    Treatment of elicited peritoneal macrophages or the macrophage cell line RAW 264.7 with high concentrations of nitric oxide donors is followed by apoptotic cell death. Analysis of the changes in the mitochondrial transmembrane potential (DeltaPsi(m)) with specific fluorescent probes showed a rapid and persistent increase of DeltaPsi(m), a potential that usually decreases in cells undergoing apoptosis through mitochondrial-dependent mechanisms. Using confocal microscopy, the release of cytochrome c from the mitochondria to the cytosol was characterized as an early event preceding the rise of DeltaPsi(m). The cytochrome c from cells treated with nitric oxide donors was modified chemically, probably through the formation of nitrotyrosine residues, suggesting the synthesis of peroxynitrite in the mitochondria. These results indicate that nitric oxide-dependent apoptosis in macrophages occurs in the presence of a sustained increase of DeltaPsi(m), and that the chemical modification and release of cytochrome c from the mitochondria precede the changes of DeltaPsi(m).-Hortelano, S., Alvarez, A. M., Boscá, L. Nitric oxide induces tyrosine nitration and release of cytochrome c preceding an increase of mitochondrial transmembrane potential in macrophages.

  6. Fucoidan from Fucus vesiculosus protects against alcohol-induced liver damage by modulating inflammatory mediators in mice and HepG2 cells.

    Science.gov (United States)

    Lim, Jung Dae; Lee, Sung Ryul; Kim, Taeseong; Jang, Seon-A; Kang, Se Chan; Koo, Hyun Jung; Sohn, Eunsoo; Bak, Jong Phil; Namkoong, Seung; Kim, Hyoung Kyu; Song, In Sung; Kim, Nari; Sohn, Eun-Hwa; Han, Jin

    2015-02-16

    Fucoidan is an l-fucose-enriched sulfated polysaccharide isolated from brown algae and marine invertebrates. In this study, we investigated the protective effect of fucoidan from Fucus vesiculosus on alcohol-induced murine liver damage. Liver injury was induced by oral administration of 25% alcohol with or without fucoidan (30 mg/kg or 60 mg/kg) for seven days. Alcohol administration increased serum aspartate aminotransferase and alanine aminotransferase levels, but these increases were suppressed by the treatment of fucoidan. Transforming growth factor beta 1 (TGF-β1), a liver fibrosis-inducing factor, was highly expressed in the alcohol-fed group and human hepatoma HepG2 cell; however, the increase in TGF-β1 expression was reduced following fucoidan administration. Treatment with fucoidan was also found to significantly reduce the production of inflammation-promoting cyclooygenase-2 and nitric oxide, while markedly increasing the expression of the hepatoprotective enzyme, hemeoxygenase-1, on murine liver and HepG2 cells. Taken together, the antifibrotic and anti-inflammatory effects of fucoidan on alcohol-induced liver damage may provide valuable insights into developing new therapeutics or interventions.

  7. Fucoidan from Fucus vesiculosus Protects against Alcohol-Induced Liver Damage by Modulating Inflammatory Mediators in Mice and HepG2 Cells

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    Jung Dae Lim

    2015-02-01

    Full Text Available Fucoidan is an l-fucose-enriched sulfated polysaccharide isolated from brown algae and marine invertebrates. In this study, we investigated the protective effect of fucoidan from Fucus vesiculosus on alcohol-induced murine liver damage. Liver injury was induced by oral administration of 25% alcohol with or without fucoidan (30 mg/kg or 60 mg/kg for seven days. Alcohol administration increased serum aspartate aminotransferase and alanine aminotransferase levels, but these increases were suppressed by the treatment of fucoidan. Transforming growth factor beta 1 (TGF-β1, a liver fibrosis-inducing factor, was highly expressed in the alcohol-fed group and human hepatoma HepG2 cell; however, the increase in TGF-β1 expression was reduced following fucoidan administration. Treatment with fucoidan was also found to significantly reduce the production of inflammation-promoting cyclooygenase-2 and nitric oxide, while markedly increasing the expression of the hepatoprotective enzyme, hemeoxygenase-1, on murine liver and HepG2 cells. Taken together, the antifibrotic and anti-inflammatory effects of fucoidan on alcohol-induced liver damage may provide valuable insights into developing new therapeutics or interventions.

  8. Endothelium negatively modulates the vascular relaxation induced by nitric oxide donor, due to uncoupling NO synthase.

    Science.gov (United States)

    Bonaventura, Daniella; Lunardi, Claure N; Rodrigues, Gerson J; Neto, Mário A; Vercesi, Juliana A; de Lima, Renata G; da Silva, Roberto S; Bendhack, Lusiane M

    2009-10-01

    Nitrosyl ruthenium complexes have been characterized as nitric oxide (NO) donors that induce relaxation in the denuded rat aorta. There are some differences in their vascular relaxation mechanisms compared with sodium nitroprusside. This study investigates whether the endothelium could interfere with the [Ru(terpy)(bdq)NO](3+)-TERPY-induced vascular relaxation, by analyzing the maximal relaxation (Emax) and potency (pD(2)) of TERPY. Vascular reactivity experiments showed that the endothelium negatively modulates (pD(2): 6.17+/-0.07) the TERPY relaxation in intact rat aortic rings compared with the denuded rat aorta (pD(2): 6.65+/-0.07). This effect is abolished by a non-selective NO-synthase (NOS) inhibitor L-NAME (pD(2): 6.46+/-0.10), by the superoxide anion (O(2)(-)) scavenger TIRON (pD(2): 6.49+/-0.08), and by an NOS cofactor BH(4) (pD(2): 6.80+/-0.10). The selective dye for O(2)(-) (DHE) shows that TERPY enhances O(2)(-) concentration in isolated endothelial cells (intensity of fluorescence (IF):11258.00+/-317.75) compared with the basal concentration (IF: 7760.67+/-381.50), and this enhancement is blocked by L-NAME (IF: 8892.33+/-1074.41). Similar results were observed in vascular smooth muscle cells (concentration of superoxide after TERPY: 2.63+/-0.17% and after TERPY+L-NAME: -4.63+/-0.14%). Considering that TERPY could induce uncoupling NOS, thus producing O(2)(-), we have also investigated the involvement of prostanoids in the negative modulation of the endothelium. The non-selective cyclooxygenase (COX) inhibitor indomethacin and the selective tromboxane (TXA(2)) receptor antagonist SQ29548 reduce the effect of the endothelium on TERPY relaxation (pD(2) INDO: 6.80+/-0.17 and SQ29548: 6.85+/-0.15, respectively). However, a selective prostaglandin F(2alpha) receptor antagonist (AH6809) does not change the endothelium effect. Moreover, TERPY enhances the concentration of TXA(2) stable metabolite (TXB(2)), but this effect is blocked by L-NAME and TIRON. The

  9. Serious drug-induced liver disease secondary to ezetimibe

    Institute of Scientific and Technical Information of China (English)

    José Castellote; Javier Adza; Rosa Rota; Anna Girbau; Xavier Xiol

    2008-01-01

    Ezetimibe is the first member of a new family of lipidlowering drugs that inhibits uptake of dietary and biliary cholesterol. It was approved by the FDA in 2002for hypercholesterolemia alone or in combination with statins. Its use has been spreading over the last years.Ezetimibe was considered a safe drug. We report a case of a woman who developed a serious hepatocellular drug-induced liver disease after 4 mo therapy with 10 mg daily of ezetimibe. After withdrawal of the drug, the patient recovered slowly. Ezetimibe may produce serious toxic hepatitis and prompt withdrawal is mandatory in case of a significant abnormality in liver testing after beginning or during treatment with ezetimibe.

  10. Albendazole-induced liver injury: a case report

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    David Ríos

    2013-05-01

    Full Text Available We report a case of a 47-year-old male, who was referred to the clinical hepatology services at Pablo Tobón Uribe Hospital for evaluation of a jaundice syndrome. After undergoing several exams, we diagnosed hepatic hydatidosis and the patient was treated with albendazole; however, after five months of uninterrupted treatment the patient again consulted and his liver test showed marked hepatocellular damage. This time, the patient was diagnosed with drug-induced liver injury due to albendazole, based on information from the clinical record, history of drug consumption, clinical and laboratory tests improved after discontinuing the medication and after discarding other possible causes; this diagnosis was supported by the CIOMS/RUCAM scale, which showed a “likely” correlation between hepatocellular damage and drug toxicity etiology. 

  11. Albendazole-induced liver injury: a case report.

    Science.gov (United States)

    Ríos, David; Restrepo, Juan C

    2013-04-01

    We report a case of a 47-year-old male, who was referred to the clinical hepatology services at Pablo Tobón Uribe Hospital for evaluation of a jaundice syndrome. After undergoing several exams, we diagnosed hepatic hydatidosis and the patient was treated with albendazole; however, after five months of uninterrupted treatment the patient again consulted and his liver test showed marked hepatocellular damage. This time, the patient was diagnosed with drug-induced liver injury due to albendazole, based on information from the clinical record, history of drug consumption, clinical and laboratory tests improved after discontinuing the medication and after discarding other possible causes; this diagnosis was supported by the CIOMS/RUCAM scale, which showed a "likely" correlation between hepatocellular damage and drug toxicity etiology.

  12. Inhibition of the mitochondrial permeability transition by cyclosporin A prevents pyrazole plus lipopolysaccharide-induced liver injury in mice.

    Science.gov (United States)

    Zhuge, Jian; Cederbaum, Arthur I

    2009-02-01

    Previous results showed that pyrazole potentiates lipopolysaccharide (LPS)-induced liver injury in mice. Mechanisms involved the overexpression of cytochrome P450 2E1 (CYP2E1), oxidative stress, and activation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). The current study was carried out to test the hypothesis that the mitochondria permeability transition (MPT) plays a role in this pyrazole plus LPS toxicity. Mice were injected intraperitoneally with pyrazole for 2 days, followed by a challenge with LPS with or without treatment with cyclosporin A (CsA), an inhibitor of the MPT. Serum alanine aminotransferase and aspartate aminotransferase were increased by pyrazole plus LPS treatment, and CsA treatment could attenuate these increases. CsA also prevented pyrazole plus LPS-induced hepatocyte necrosis. Formation of 4-hydroxynonenal protein adducts and 3-nitrotyrosine protein adducts in liver tissue was increased by the pyrazole plus LPS treatment, and CsA treatment blunted these increases. Swelling, cytochrome c release from mitochondria to the cytosol, and lipid peroxidation were increased in mitochondria isolated from the pyrazole plus LPS-treated mice, and CsA treatment prevented these changes. CsA did not prevent the increased levels of inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNF-alpha), pp38 MAPK, and p-JNK2. In conclusion, although CsA does not prevent elevations in upstream mediators of the pyrazole plus LPS toxicity (iNOS, TNF-alpha, CYP2E1, MAPK), it does protect mice from the pyrazole plus LPS-induced liver toxicity by preventing the MPT and release of cytochrome c and decreasing mitochondrial oxidative stress. These results indicate that mitochondria are the critical targets of pyrazole plus LPS in mediating liver injury.

  13. Role of endogenous nitric oxide on PAF-induced vascular and respiratory effects

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    M. Clement

    1995-01-01

    Full Text Available The role of endogenous nitric oxide (NO on vascular and respiratory smooth muscle basal tone was evaluated in six anaesthetized, paralysed, mechanically ventilated pigs. The involvement of endogenous NO in PAF-induced shock and airway hyperresponsiveness was also studied. PAF (50 ng/kg, i.v. was administered before and after pretreatment with NG-nitro-L-arginine methyl ester (L-NAME, 10 mg/kg, i.v., an NO synthesis inhibitor. PAF was also administered to three of these pigs after indomethacin infusion (3 mg/kg, i.v.. In normal pigs, L-NAME increased systemic and pulmonary vascular resistances, caused pulmonary hypertension and reduced cardiac output and stroke volume. The pulmonary vascular responses were correlated with the increase in static and dynamic lung elastances, without changing lung resistance. Inhibition of NO synthesis enhanced the PAF-dependent increase in total, intrinsic and viscoelastic lung resistances, without affecting lung elastances or cardiac activity. The systemic hypotensive effect of PAF was not abolished by pretreatment with L-NAME or indomethacin. This indicates that systemic hypotension is not correlated with the release of endogenous NO or prostacyclines. Indomethacin completely abolished the PAF-dependent respiratory effects.

  14. Inhibition of nitric oxide synthases abrogates pregnancy-induced uterine vascular expansive remodeling.

    Science.gov (United States)

    Osol, George; Barron, Carolyn; Gokina, Natalia; Mandala, Maurizio

    2009-01-01

    It was the aim of this study to test the hypothesis that hypertension and/or inhibition of nitric oxide (NO) synthases alters uterine vascular remodeling during pregnancy. Using a model of hypertension (NO synthase inhibition with L-NAME) in nonpregnant and pregnant rats, comparisons were made with age-matched controls, as well as with animals receiving hydralazine along with L-NAME to maintain normotension in the presence of NO synthase inhibition. Circumferential and axial remodeling of large (main uterine, MUA) and small (premyometrial radial) arteries were quantified and compared. L-NAME treatment prevented expansive circumferential remodeling of the MUA; cotreatment with hydralazine was without effect. Circumferential remodeling of smaller premyometrial radial arteries was also significantly attenuated in hypertensive pregnant animals, while premyometrial radial arteries from rats receiving hydralazine with L-NAME were of intermediate diameter. Neither hypertension nor NO synthase inhibition had any effect on the substantial (200-300%) axial growth of MUA or premyometrial radial arteries. NO plays a major role in facilitating pregnancy-induced expansive remodeling in the uterine circulation, particularly in larger arteries. Some beneficial effects of hydralazine on expansive circumferential remodeling were noted in smaller radial vessels, and these may be linked to its prevention of systemic hypertension and/or to local effects on the arterial wall. Neither NO synthase inhibition nor hypertension had any effect on arterial longitudinal growth.

  15. Impaired acetylcholine-induced cutaneous vasodilation in young smokers: roles of nitric oxide and prostanoids.

    Science.gov (United States)

    Fujii, Naoto; Reinke, Maggie C; Brunt, Vienna E; Minson, Christopher T

    2013-03-01

    Cigarette smoking attenuates acetylcholine (ACh)-induced cutaneous vasodilation in humans, but the underlying mechanisms are unknown. We tested the hypothesis that smokers have impaired nitric oxide (NO)- and cyclooxygenase (COX)-dependent cutaneous vasodilation to ACh infusion. Twelve young smokers, who have smoked more than 5.2 ± 0.7 yr with an average daily consumption of 11.4 ± 1.2 cigarettes, and 12 nonsmokers were tested. Age, body mass index, and resting mean arterial pressure were similar between the groups. Cutaneous vascular conductance (CVC) was evaluated as laser-Doppler flux divided by mean arterial pressure, normalized to maximal CVC (local heating to 43.0°C plus sodium nitroprusside administration). We evaluated the increase in CVC from baseline to peak (CVCΔpeak) and area under the curve of CVC (CVCAUC) during a bolus infusion (1 min) of 137.5 μM ACh at four intradermal microdialysis sites: 1) Ringer (control), 2) 10 mM N(G)-nitro-l-arginine methyl ester (l-NAME; NO synthase inhibitor), 3) 10 mM ketorolac (COX inhibitor), and 4) combination of l-NAME + ketorolac. CVCΔpeak and CVCAUC at the Ringer site in nonsmokers were greater than in smokers (CVCΔpeak, 42.9 ± 5.1 vs. 22.3 ± 3.5%max, P vasodilation in young smokers is related to diminished NO- and COX-dependent vasodilation.

  16. Contribution of nitric oxide in the contraction-induced rapid vasodilation in young and older adults.

    Science.gov (United States)

    Casey, Darren P; Walker, Branton G; Ranadive, Sushant M; Taylor, Jennifer L; Joyner, Michael J

    2013-08-15

    We tested the hypothesis that reduced nitric oxide (NO) bioavailability contributes to the attenuated peak and total vasodilation following single-muscle contractions in older adults. Young (n = 10; 24 ± 2 yr) and older (n = 10; 67 ± 2 yr) adults performed single forearm contractions at 10, 20, and 40% of maximum during saline infusion (control) and NO synthase (NOS) inhibition via N(G)-monomethyl-l-arginine. Brachial artery diameters and velocities were measured using Doppler ultrasound and forearm vascular conductance (FVC; in ml·min(-1)·100 mmHg(-1)) was calculated from blood flow (ml/min) and blood pressure (mmHg). Peak and total vasodilator responses [change (Δ) in FVC from baseline] were attenuated in older adults at all intensities (P vasodilator response (area under the curve) with NOS inhibition was also greater in young vs. older adults at all intensities. Our data suggest that contraction-induced rapid vasodilation is mediated in part by NO, and that the contribution of NO is greater in young adults.

  17. Impaired Healing of a Cutaneous Wound in an Inducible Nitric Oxide Synthase-Knockout Mouse

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    Takashi Kitano

    2017-01-01

    Full Text Available Background. We investigated the effects of loss of inducible nitric oxide synthase (iNOS on the healing process of cutaneous excisional injury by using iNOS-null (KO mice. Population of granulation tissue-related cell types, that is, myofibroblasts and macrophages, growth factor expression, and reepithelialization were evaluated. Methods. KO and wild type (WT mice of C57BL/6 background were used. Under general anesthesia two round full-thickness excision wounds of 5.0 mm in diameter were produced in dorsal skin. After specific intervals of healing, macroscopic observation, histology, immunohistochemistry, and real-time reverse transcription-polymerase chain reaction (RT-PCR were employed to evaluate the healing process. Results. The loss of iNOS retards granulation tissue formation and reepithelialization in excision wound model in mice. Detailed analyses showed that myofibroblast appearance, macrophage infiltration, and mRNA expression of transforming growth factor b and of collagen 1α2 were all suppressed by lacking iNOS. Conclusions. iNOS is required in the process of cutaneous wound healing. Lacking iNOS retards macrophage invasion and its expression of fibrogenic components that might further impair fibrogenic behaviors of fibroblasts.

  18. Role of nitric oxide in the radiation-induced bystander effect.

    Science.gov (United States)

    Yakovlev, Vasily A

    2015-12-01

    Cells that are not irradiated but are affected by "stress signal factors" released from irradiated cells are called bystander cells. These cells, as well as directly irradiated ones, express DNA damage-related proteins and display excess DNA damage, chromosome aberrations, mutations, and malignant transformation. This phenomenon has been studied widely in the past 20 years, since its first description by Nagasawa and Little in 1992, and is known as the radiation-induced bystander effect (RIBE). Several factors have been identified as playing a role in the bystander response. This review will focus on one of them, nitric oxide (NO), and its role in the stimulation and propagation of RIBE. The hydrophobic properties of NO, which permit its diffusion through the cytoplasm and plasma membranes, allow this signaling molecule to easily spread from irradiated cells to bystander cells without the involvement of gap junction intercellular communication. NO produced in irradiated tissues mediates cellular regulation through posttranslational modification of a number of regulatory proteins. The best studied of these modifications are S-nitrosylation (reversible oxidation of cysteine) and tyrosine nitration. These modifications can up- or down-regulate the functions of many proteins modulating different NO-dependent effects. These NO-dependent effects include the stimulation of genomic instability (GI) and the accumulation of DNA errors in bystander cells without direct DNA damage. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Adaptative nitric oxide overproduction in perivascular adipose tissue during early diet-induced obesity.

    Science.gov (United States)

    Gil-Ortega, Marta; Stucchi, Paula; Guzmán-Ruiz, Rocío; Cano, Victoria; Arribas, Silvia; González, M Carmen; Ruiz-Gayo, Mariano; Fernández-Alfonso, Maria S; Somoza, Beatriz

    2010-07-01

    Perivascular adipose tissue (PVAT) plays a paracrine role in regulating vascular tone. We hypothesize that PVAT undergoes adaptative mechanisms during initial steps of diet-induced obesity (DIO) which contribute to preserve vascular function. Four-week-old male C57BL/6J mice were assigned either to a control [low-fat (LF); 10% kcal from fat] or to a high-fat diet (HF; 45% kcal from fat). After 8 wk of dietary treatment vascular function was analyzed in the whole perfused mesenteric bed (MB) and in isolated mesenteric arteries cleaned of PVAT. Relaxant responses to acetylcholine (10(-9)-10(-4) m) and sodium nitroprusside (10(-12)-10(-5) m) were significantly ameliorated in the whole MB from HF animals. However, there was no difference between HF and LF groups in isolated mesenteric arteries devoid of PVAT. The enhancement of relaxant responses detected in HF mice was not attributable to an increased release of nitric oxide (NO) from the endothelium nor to an increased sensitivity and/or activity of muscular guanilylcyclase. Mesenteric PVAT of HF animals showed an increased bioavailability of NO, detected by 4,5-diaminofluorescein diacetate (DAF2-DA) staining, which positively correlated with plasma leptin levels. DAF-2DA staining was absent in PVAT from ob/ob mice but was detected in these animals after 4-wk leptin replacement. The main finding in this study is that adaptative NO overproduction occurs in PVAT during early DIO which might be aimed at preserving vascular function.

  20. Alveolar macrophage inducible nitric oxide synthase-dependent pulmonary microvascular endothelial cell septic barrier dysfunction.

    Science.gov (United States)

    Farley, K S; Wang, L F; Law, C; Mehta, S

    2008-11-01

    Inducible nitric oxide (NO) synthase (iNOS) from neutrophils and alveolar macrophages (AM) contributes to the pathophysiology of murine septic acute lung injury (ALI). It is not known if AM iNOS has a direct effect on septic pulmonary microvascular endothelial cell (PMVEC) permeability. We hypothesized that AM iNOS mediates PMVEC permeability in vitro under septic conditions through NO and peroxynitrite. 100,000 confluent PMVEC on cell-culture inserts were co-incubated with iNOS+/+ vs. iNOS-/- AM, in various ratios of AM to PMVEC. PMVEC injury was assessed by trans-PMVEC Evans Blue-labelled albumin flux in the presence or absence of cytomix (equimolar TNF-alpha, IL-1beta and IFN-gamma). Cytomix stimulation dose-dependently increased trans-PMVEC EB-albumin flux, which was exaggerated (1.4+/-0.1% vs. 0.4+/-0.1% in unstimulated PMVEC, pDETA-NONOate. Septic iNOS+/+ AM-dependent trans-PMVEC albumin leak was significantly attenuated by pharmacologic iNOS inhibition (L-NAME and 1400W), and scavenging of either NO (oxyhemoglobin), superoxide (PEG-SOD), or peroxynitrite (FeTPPS). Exogenous NO (DETA-NONOate) had no effect on PMVEC permeability. These data are consistent with a direct role of AM iNOS in septic PMVEC barrier dysfunction, which is likely mediated, in part, through peroxynitrite.

  1. Gene expression of inducible nitric oxide synthase in injured spinal cord tissue

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To investigate gene expression of inducible nitric oxide synthase (iNOS) in injured spinal cord tissue of rats.Methods: Thirty-six adult Sprague-Dawley rats were divided randomly into six groups: a normal group and five injury groups, six animals in each group. Animals in the injury groups were killed at 2, 6, 12, 24, 48 hours after injury, respectively. A compression injury model of spinal cord was established according to Nystrom B et al, and gene expression of iNOS in spinal cord tissue was examined by means of reverse transcription polymerase chain reaction (RT-PCR).Results: Gene expression of iNOS was not detectable in normal spinal cord tissue but was seen in the injury groups. The expression was gradually up-regulated, reaching the maximum at 24 hours. The expression at 48hours began to decrease but was still significantly higher than that at 2 hours.Conclusions: iNOS is not involved in the normal physiological activities of spinal cord. Expression of iNOS is up-regulated in spinal cord tissue in response to injury and the up-regulation exists mainly in the late stage after injury. Over-expression of iNOS may contribute to the late injury of spinal cord.

  2. Inducible nitric oxide synthase (NOS II) is constitutive in human neutrophils.

    Science.gov (United States)

    Cedergren, Jan; Follin, Per; Forslund, Tony; Lindmark, Maria; Sundqvist, Tommy; Skogh, Thomas

    2003-10-01

    The objective was to study the expression of inducible nitric oxide synthase (NOS II) in and NO production by human blood neutrophils and in in vivo exudated neutrophils. Cellular expression of NOS II was evaluated by flow cytometry in whole blood, in isolated blood neutrophils, and in neutrophils obtained by exudation in vivo into skin chambers. Neutrophil NOS II was also demonstrated by Western blotting. Uptake of 3H-labelled L-arginine was studied in vitro and NOS activity measured in a whole cell assay by the conversion of 3H-arginine to 3H-citrulline. In contrast to unseparated blood cells, NOS II was demonstrable both in isolated blood neutrophils and exudated cells. The failure to detect NOS II by flow cytometry in whole blood cells thus proved to be due to the quenching effect of hemoglobin. Western blotting revealed a 130 kD band corresponding to NOS II in isolated blood neutrophils, but detection was dependent on diisopropylfluorophosphate for proteinase inhibition. L-arginine was taken up by neutrophils, but enzymatic activity could not be demonstrated. We conclude that human neutrophils constitutively express NOS II, but that its demonstration by FITC-labelling is inhibited by hemoglobin-mediated quenching in whole blood samples.

  3. Expression of the inducible nitric oxide synthase gene in diaphragm and skeletal muscle.

    Science.gov (United States)

    Thompson, M; Becker, L; Bryant, D; Williams, G; Levin, D; Margraf, L; Giroir, B P

    1996-12-01

    Nitric oxide (NO) is a pluripotent molecule that can be secreted by skeletal muscle through the activity of the neuronal constitutive isoform of NO synthase. To determine whether skeletal muscle and diaphragm might also express the macrophage-inducible form of NO synthase (iNOS) during provocative states, we examined tissue from mice at serial times after intravenous administration of Escherichia coli endotoxin. In these studies, iNOS mRNA was strongly expressed in the diaphragm and skeletal muscle of mice 4 h after intravenous endotoxin and was significantly diminished by 8 h after challenge. Induction of iNOS mRNA was followed by expression of iNOS immunoreactive protein on Western immunoblots. Increased iNOS activity was demonstrated by conversion of arginine to citrulline. Immunochemical analysis of diaphragmatic explants exposed to endotoxin in vitro revealed specific iNOS staining in myocytes, in addition to macrophages and endothelium. These results may be important in understanding the pathogenesis of respiratory pump failure during septic shock, as well as skeletal muscle injury during inflammation or metabolic stress.

  4. Contribution of myeloperoxidase and inducible nitric oxide synthase to pathogenesis of psoriasis

    Directory of Open Access Journals (Sweden)

    Nursel Dilek

    2016-12-01

    Full Text Available Introduction : Histological changes of psoriasis include invasion of neutrophils into the epidermis and formation of Munro abscesses in the epidermis. Neutrophils are the predominant white blood cells in circulation when stimulated; they discharge the abundant myeloperoxidase (MPO enzyme that uses hydrogen peroxide to oxidize chloride for killing ingested bacteria. Aim: To investigate the contribution of neutrophils to the pathogenesis of psoriasis at the blood and tissue levels through inducible nitric oxide synthase (iNOS and MPO. Material and methods: A total of 50 adult patients with a chronic plaque form of psoriasis and 25 healthy controls were enrolled to this study. Serum MPO and iNOS levels were measured using ELISA method. Two biopsy specimens were taken in each patient from the center of the lesion and uninvolved skin. Immunohistochemistry was performed for MPO and iNOS on both normal and psoriasis vulgaris biopsies. Results: While a significant difference between serum myeloperoxidase levels were detected, a similar statistical difference between participants in the serum iNOS levels was not found. In immunohistochemistry, intensely stained leukocytes with MPO and intensely staining with iNOS in psoriatic skin was observed. Conclusions : Neutrophils in psoriasis lesions are actively producing MPO and this indirectly triggers the synthesis of iNOS. Targeting of MPO or synthesis of MPO in the lesion area may contribute to development of a new treatment option.

  5. Expression of Neuronal and Inducible Nitric Oxide Synthase Isoforms and Generation of Protein Nitrotyrosine in Rat Brain Following Hypobaric Hypoxia

    Science.gov (United States)

    2001-06-01

    compilation report: ADPO11059 thru ADP011100 UNCLASSIFIED 38- 1 Expression of Neuronal and Inducible Nitric Oxide Synthase Isoforms and Generation of Protein...cloned, both from chondrocytes (Charles et al., 1993) and hepatocytes (Geller et al., 1993). The neurotoxic effects of NO is mediated by formation of...injection at multiple sites on the back. Four boosts of 1 /6 of the conjugate emulsified in Freund’s incomplete adjuvant were given by subcutaneous injection

  6. Astaxanthin pretreatment attenuates acetaminophen-induced liver injury in mice.

    Science.gov (United States)

    Zhang, Jingyao; Zhang, Simin; Bi, Jianbin; Gu, Jingxian; Deng, Yan; Liu, Chang

    2017-04-01

    Acetaminophen (APAP) is a conventional drug widely used in the clinic because of its antipyretic-analgesic effects. However, accidental or intentional APAP overdoses induce liver injury and even acute liver failure (ALF). Astaxanthin (ASX) is the strongest antioxidant in nature that shows preventive and therapeutic properties, such as ocular protection, anti-tumor, anti-diabetes, anti-inflammatory, and immunomodulatory effects. The aim of present study was to determine whether ASX pretreatment provides protection against APAP-induced liver failure. Male C57BL/6 mice were randomly divided into 7 groups, including control, oil, ASX (30mg/kg or 60mg/kg), APAP and APAP+ASX (30mg/kg or 60mg/kg) groups. Saline, olive oil and ASX were administered for 14days. The APAP and APAP+ASX groups were given a peritoneal injection of 700mg/kg or 300mg/kg APAP to determine the 5-day survival rate and for further observation, respectively. Blood and liver samples were collected to detect alanine transaminase (ALT), aspartate transaminase (AST), inflammation, oxidative stress and antioxidant systems, and to observe histopathologic changes and key proteins in the mitogen-activated protein kinase (MAPK) family. ASX pretreatment before APAP increased the 5-day survival rate in a dose-dependent manner and reduced the ALT, AST, hepatic necrosis, reactive oxygen species (ROS) generation, lipid peroxidation (LPO), oxidative stress and pro-inflammatory factors. ASX protected against APAP toxicity by inhibiting the depletion of glutathione (GSH) and superoxide dismutase (SOD). Administration of ASX did not change the expression of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and P38. However, phosphorylation of JNK, ERK and P38 was reduced, consistent with the level of tumor necrosis factor alpha (TNF-α) and TNF receptor-associated factor 2 (TRAF2). ASX provided protection for the liver against APAP hepatotoxicity by alleviating hepatocyte necrosis, blocking ROS

  7. Spinal motoneuron synaptic plasticity after axotomy in the absence of inducible nitric oxide synthase

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    Zanon Renata G

    2010-05-01

    Full Text Available Abstract Background Astrocytes play a major role in preserving and restoring structural and physiological integrity following injury to the nervous system. After peripheral axotomy, reactive gliosis propagates within adjacent spinal segments, influenced by the local synthesis of nitric oxide (NO. The present work investigated the importance of inducible nitric oxide synthase (iNOS activity in acute and late glial responses after injury and in major histocompatibility complex class I (MHC I expression and synaptic plasticity of inputs to lesioned alpha motoneurons. Methods In vivo analyses were carried out using C57BL/6J-iNOS knockout (iNOS-/- and C57BL/6J mice. Glial response after axotomy, glial MHC I expression, and the effects of axotomy on synaptic contacts were measured using immunohistochemistry and transmission electron microscopy. For this purpose, 2-month-old animals were sacrificed and fixed one or two weeks after unilateral sciatic nerve transection, and spinal cord sections were incubated with antibodies against classical MHC I, GFAP (glial fibrillary acidic protein - an astroglial marker, Iba-1 (an ionized calcium binding adaptor protein and a microglial marker or synaptophysin (a presynaptic terminal marker. Western blotting analysis of MHC I and nNOS expression one week after lesion were also performed. The data were analyzed using a two-tailed Student's t test for parametric data or a two-tailed Mann-Whitney U test for nonparametric data. Results A statistical difference was shown with respect to astrogliosis between strains at the different time points studied. Also, MHC I expression by iNOS-/- microglial cells did not increase at one or two weeks after unilateral axotomy. There was a difference in synaptophysin expression reflecting synaptic elimination, in which iNOS-/- mice displayed a decreased number of the inputs to alpha motoneurons, in comparison to that of C57BL/6J. Conclusion The findings herein indicate that i

  8. Inducible nitric oxide synthase contributes to intermittent hypoxia against ischemia/reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Hai-lei DING; Hai-feng ZHU; Jian-wen DONG; Wei-zhong ZHU; Wei-wei YANG; Huang-tian YANG; Zhao-nian ZHOU

    2005-01-01

    Aim: To investigate the role of inducible nitric oxide synthase (iNOS)-derived nitric oxide (NO) in the cardioprotection of intermittent hypoxia (IH) against ischemia/reperfusion (I/R) injury. Methods: Langendorff-perfused isolated rat hearts were used to measure variables of left ventricular function during baseline perfusion, ischemia, and reperfusion period. Nitrate plus nitrite (NOx) content in myocardium was measured using a biochemical method, iNOS mRNA and protein expression in rat left ventricles were detected using reverse transcription polymerase chain reaction (RT-PCR) and Western blot, respectively. Results: Myocardial function recovered better in IH rat hearts than in normoxic control hearts.The iNOS-selective inhibitor aminoguanidine (AG) (100 μmol/L) significantly inhibited the protective effects of IH, but had no influence on normoxic rat hearts.The baseline content of NOx in IH hearts was higher than that in normoxic hearts.After 30 min ischemia, the NOx level in normoxic hearts increased compared to the corresponding baseline level, whereas there was no significant change in IH hearts. However, the NOx level in IH hearts was still higher than that of normoxic hearts during ischemia and reperfusion period. AG 100 μmol/L significantly diminished the NOx content in IH and normoxic hearts during ischemia and reperfusion period. The baseline levels of iNOS mRNA and protein in IH hearts were higher than those of normoxic hearts. Compared to the corresponding baseline level,iNOS mRNA and protein levels in normoxic rat hearts increased and those in IH rat hearts decreased after reperfusion. The addition of AG 100 μmol/L significantly decreased iNOS mRNA and protein expression in IH rat hearts after I/R.Conclusion: IH upregulated the baseline level of iNOS mRNA and protein expression leading to an increase in NO production, which may play an important role in the cardiac protection of IH against I/R injury.

  9. Nitric oxide production and inducible nitric oxide synthase protein expression in human abdominal aortic aneurysms and cultured aneurismal smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    LIAO Ming-fang; JING Zai-ping; BAO Jun-min; ZHAO Zhi-qing; MEI Zhi-jun; LU Qing-sheng; CUI Jia-sen; QU Le-feng; ZHANG Su-zhen

    2006-01-01

    Objective:To investigate the production of nitric oxide(NO) and the expression of inducible nitric oxide synthase (iNOS), and their possible role in abdominal aortic aneurysm (AAA). Methods: A total of 28 patients with AAA, 10 healthy controls, and 8 patients with arterial occlusive disease were enrolled into this study. Standard colorimetric assay was used to examine NO concentration in plasma from patients with AAA and normal controls, and in cultured smooth muscle cells (SMCs). Expression of iNOS in aortas and cultured SMCs were detected by immunochemistry. The correlation of iNOS expression with age of the patient, size of aneurysm, and degree of inflammation was also investigated by CochranMantel-Haenszel x2 test and Kendall correlation. Results: Expression of iNOS increased significantly in the wall of aneurism in the patients with AAA compared to the healthy controls (P<0.05) and the patients with occlusive arteries (P<0. 05). iNOS protein and media NOx (nitrite+nitrate) also increased in cultured SMCs from human AAA (n=4, P<0.05), while plasma NOx decreased in patients with AAA (n=25) compared to the healthy controls (n= 20). There was a positive correlation between iNOS protein and the degree of inflammation in aneurismal wall (Kendall coefficient = 0. 5032, P = 0. 0029). Conclusion:SMCs and inflammatory cells are main cellular sources of increased iNOS in AAA, and NO may play a part in pathogenesis in AAA through inflammation, SMCs and oxidative stress.

  10. Retinal cell death induced by TRPV1 activation involves NMDA signaling and upregulation of nitric oxide synthases.

    Science.gov (United States)

    Leonelli, Mauro; Martins, Daniel O; Britto, Luiz R G

    2013-04-01

    The activation of the transient receptor potential vanilloid type 1 channel (TRPV1) has been correlated with oxidative and nitrosative stress and cell death in the nervous system. Our previous results indicate that TRPV1 activation in the adult retina can lead to constitutive and inducible nitric oxide synthase-dependent protein nitration and apoptosis. In this report, we have investigated the potential effects of TRPV1 channel activation on nitric oxide synthase (NOS) expression and function, and the putative participation of ionotropic glutamate receptors in retinal TRPV1-induced protein nitration, lipid peroxidation, and DNA fragmentation. Intravitreal injections of the classical TRPV1 agonist capsaicin up-regulated the protein expression of the inducible and endothelial NOS isoforms. Using 4,5-diaminofluorescein diacetate for nitric oxide (NO) imaging, we found that capsaicin also increased the production of NO in retinal blood vessels. Processes and perikarya of TRPV1-expressing neurons in the inner nuclear layer of the retina were found in the vicinity of nNOS-positive neurons, but those two proteins did not colocalize. Retinal explants exposed to capsaicin presented high protein nitration, lipid peroxidation, and cell death, which were observed in the inner nuclear and plexiform layers and in ganglion cells. This effect was partially blocked by AP-5, a NMDA glutamate receptor antagonist, but not by CNQX, an AMPA/kainate receptor antagonist. These data support a potential role for TRPV1 channels in physiopathological retinal processes mediated by NO, which at least in part involve glutamate release.

  11. Molecular regulation of Trypanosoma congolense-induced nitric oxide production in macrophages.

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    Rani Singh

    Full Text Available BALB/c mice are highly susceptible while C57BL/6 mice are relatively resistant to experimental Trypanosoma congolense infection. Several reports show that an early interferon-gamma (IFN-γ response in infected mice is critically important for resistance via the activation of macrophages and production of nitric oxide (NO. NO is a pivotal effector molecule and possesses both cytostatic and cytolytic properties for the parasite. However, the molecular mechanisms leading to T. congolense (TC-induced NO release from macrophages are not known. In this study, we investigated the signaling pathways induced by trypanosomes in immortalized macrophage cell lines from the highly susceptible BALB/c (BALB.BM and relatively resistant C57Bl/6 (ANA-1 mice. We found that T. congolense whole cell extract (TC-WCE induces significantly higher levels of NO production in IFN-γ-primed ANA-1 than BALB.BM cells, which was further confirmed in primary bone marrow-derived macrophage (BMDM cultures. NO production was dependent on mitogen-activated protein kinase (MAPK, including p38, Erk1/2, and JNK phosphorylation and was significantly inhibited by specific MAPK inhibitors in BALB.BM, but not in ANA-1 cells. In addition, T. congolense- and IFN-γ-induced NO production in ANA-1 and BALB.BM cells was dependent on STAT1 phosphorylation and was totally suppressed by the use of fludarabine (a specific STAT1 inhibitor. We further show that T. congolense induces differential iNOS transcriptional promoter activation in IFN-γ-primed cells, which is dependent on the activation of both GAS1 and GAS2 transcription factors in BALB.BM but only on GAS1 in ANA-1 cells. Taken together, our findings show the existence of differential signalling events that lead to NO production in macrophages from the highly susceptible and relatively resistant mice following treatment with IFN-γ and T. congolense. Understanding these pathways may help identify immunomodulatory mechanisms that regulate

  12. Rearrangements of microtubule cytoskeleton in stomatal closure of Arabidopsis induced by nitric oxide

    Institute of Scientific and Technical Information of China (English)

    ZHANG YongMei; WU ZhongYi; WANG XueChen; YU Rong

    2008-01-01

    NO (nitric oxide), known as a key signal molecule in plant, plays important roles in regulation of stomatal movement. In this study, microtubule dynamics and its possible mechanism in the NO signal pathway were investigated. The results were as follows: (ⅰ) In vivo stomatal aperture assays revealed that both vinblastine (microtubule-disrupting drug) and SNP (exogenous NO donor) prevented stomatal opening in the light, and vinblastine even could enhance the inhibitory effect of SNP, whereas taxol (a microtubule-stabilizing agent) was able to reduce this effect; (ⅱ) microtubules in the opening Arabi-dopsis guard cells expressing GFP:α-tubulin-6 (AtGFP:α-tubulin-6) were organized in parallel, straight and dense bundles, radiating from the ventral side to the dorsal side, and most of them were localized perpendicularly to the ventral wall; (ⅲ) under the same environmental conditions, treated with SNP for 30 min, the radial arrays of microtubules in guard cells began to break down, twisted partially and be-came oblique or exhibited a random pattern; (ⅳ) furthermore, the involvement of cytosolic Ca2+ in this event was tested. Stomatal aperture assays revealed that BAPTA-AM (a chelator of Ca2+) greatly sup-pressed the effect of NO on stomatal closure; however, it did not show the same function on stomatal closure induced by vinblastine. When BAPTA-AM was added to the SNP-pretreated solution, the SNP-induced disordered microtubulue cytoskeleton in guard cells underwent rearrangement in a time-dependent manner. After 30 min of treatment with BAPTA-AM, the cortical microtubules resumed the original radial distribution, almost the same as the control. All this indicates that NO may promote rearrangement of microtubule cytoskeleton via elevation of [Ca2+]cyt (free Ca2+ concentration in the cy-toplasm), finally leading to stomatal closure.

  13. Allosteric inhibitors of inducible nitric oxide synthase dimerization discovered via combinatorial chemistry

    Science.gov (United States)

    McMillan, Kirk; Adler, Marc; Auld, Douglas S.; Baldwin, John J.; Blasko, Eric; Browne, Leslie J.; Chelsky, Daniel; Davey, David; Dolle, Ronald E.; Eagen, Keith A.; Erickson, Shawn; Feldman, Richard I.; Glaser, Charles B.; Mallari, Cornell; Morrissey, Michael M.; Ohlmeyer, Michael H. J.; Pan, Gonghua; Parkinson, John F.; Phillips, Gary B.; Polokoff, Mark A.; Sigal, Nolan H.; Vergona, Ronald; Whitlow, Marc; Young, Tish A.; Devlin, James J.

    2000-01-01

    Potent and selective inhibitors of inducible nitric oxide synthase (iNOS) (EC 1.14.13.39) were identified in an encoded combinatorial chemical library that blocked human iNOS dimerization, and thereby NO production. In a cell-based iNOS assay (A-172 astrocytoma cells) the inhibitors had low-nanomolar IC50 values and thus were >1,000-fold more potent than the substrate-based direct iNOS inhibitors 1400W and N-methyl-l-arginine. Biochemical studies confirmed that inhibitors caused accumulation of iNOS monomers in mouse macrophage RAW 264.7 cells. High affinity (Kd ≈ 3 nM) of inhibitors for isolated iNOS monomers was confirmed by using a radioligand binding assay. Inhibitors were >1,000-fold selective for iNOS versus endothelial NOS dimerization in a cell-based assay. The crystal structure of inhibitor bound to the monomeric iNOS oxygenase domain revealed inhibitor–heme coordination and substantial perturbation of the substrate binding site and the dimerization interface, indicating that this small molecule acts by allosterically disrupting protein–protein interactions at the dimer interface. These results provide a mechanism-based approach to highly selective iNOS inhibition. Inhibitors were active in vivo, with ED50 values of <2 mg/kg in a rat model of endotoxin-induced systemic iNOS induction. Thus, this class of dimerization inhibitors has broad therapeutic potential in iNOS-mediated pathologies. PMID:10677491

  14. Cholesterol and sphingolipids in alcohol-induced liver injury.

    Science.gov (United States)

    Fernández, Anna; Colell, Anna; Garcia-Ruiz, Carmen; Fernandez-Checa, José C

    2008-03-01

    The pathogenesis of alcohol-induced liver disease (ALD) is still poorly understood. One of the clues to its progression relates to the alcohol-mediated susceptibility of hepatocytes to cell death by reactive oxygen species (ROS) and inflammatory cytokines. Tumor necrosis factor alpha (TNF) has been considered a key ALD mediator with acidic sphingomyelinase (ASMase)-mediated ceramide generation playing a critical role. TNF receptor 1 and 2 knock-out mice or ASMase(-/-) mice exhibit resistance to alcohol-mediated fatty liver and cell death. Furthermore, alcohol feeding has been shown to sensitize hepatocytes to TNF due to the limitation of mitochondrial glutathione (mGSH) through impaired import of GSH from the cytosol due to altered membrane order parameter caused by mitochondrial cholesterol increase. Selective pharmacological depletion of mGSH sensitizes hepatocytes to TNF-mediated cell death, which reproduces the observations found with alcohol feeding. TNF signaling analyses in hepatocytes with or without mGSH depletion indicate that mGSH prevents cardiolipin peroxidation (CLOOH) formation by TNF-induced ROS via ASMase and that CLOOH cooperates with oligomerized Bax to cause mitochondrial outer membrane permeabilization through destabilization of the lipid bilayer via increased bilayer-to-inverted hexagonal phase transitions. Thus, activation of ASMase and cholesterol-mediated mGSH depletion both collaborate to promote alcohol-induced TNF-mediated hepatocellular damage, suggesting novel therapeutic opportunities in ALD.

  15. IL-6 Improves the Nitric Oxide-Induced Cytotoxic CD8+ T Cell Dysfunction in Human Chagas Disease

    Science.gov (United States)

    Sanmarco, Liliana Maria; Visconti, Laura Marina; Eberhardt, Natalia; Ramello, Maria Cecilia; Ponce, Nicolás Eric; Spitale, Natalia Beatriz; Vozza, Maria Lola; Bernardi, Germán Andrés; Gea, Susana; Minguez, Angel Ramón; Aoki, Maria Pilar

    2016-01-01

    Reactive oxygen and nitrogen species are important microbicidal agents and are also involved in lymphocyte unresponsiveness during experimental infections. Many of the biological effects attributed to nitric oxide are mediated by peroxynitrites, which induce the nitration of immune cells, among others. Our group has demonstrated that nitric oxide is involved in the suppressive activity of myeloid-derived suppressor cells in Trypanosoma cruzi-infected mice, with a higher number of CD8+ T cells suffering surface-nitration compared to uninfected controls. Studying the functional and phenotypic features of peripheral CD8+ T cells from chagasic patients and human cells experimentally infected with T. cruzi, we found that different regulatory mechanisms impaired the effector functions of T cytotoxic population from seropositive patients. Peripheral leukocytes from chagasic patients showed increased nitric oxide production concomitant with increased tyrosine nitration of CD8+ T cells. Additionally, this cytotoxic population exhibited increased apoptotic rate, loss of the TCRζ-chain, and lower levels of CD107a, a marker of degranulation. Strikingly, IL-6 stimulation of in vitro-infected peripheral blood mononuclear cells obtained from healthy donors, blunted T. cruzi-induced nitration of CD3+CD8+ cells, and increased their survival. Furthermore, the treatment of these cultures with an IL-6 neutralizing antibody increased the percentage of T. cruzi-induced CD8+ T cell nitration and raised the release of nitric oxide. The results suggest that the under-responsiveness of cytotoxic T cell population observed in the setting of long-term constant activation of the immune system could be reverted by the pleiotropic actions of IL-6, since this cytokine improves its survival and effector functions. PMID:28066435

  16. Piroxicam reverses endotoxin-induced hypotension in rats: contribution of vasoactive eicosanoids and nitric oxide.

    Science.gov (United States)

    Buharalioglu, C Kemal; Korkmaz, Belma; Cuez, Tuba; Sahan-Firat, Seyhan; Sari, Ayse Nihal; Malik, Kafait U; Tunctan, Bahar

    2011-09-01

    Nitric oxide (NO) produced by inducible NO synthase (iNOS) is responsible for endotoxin-induced vascular hyporeactivity and hypotension resulting in multiple organ failure. Endotoxic shock is also characterized by decreased expression of constitutive cyclooxygenase (COX-1), cytochrome P450 (CYP) 4A and endothelial NOS (eNOS). Our previous studies demonstrated that dual inhibition of iNOS and COX with a selective COX-2 inhibitor, NS-398, or a non-selective COX inhibitor, indomethacin, restores blood pressure presumably because of increased production of 20-hydroxyeicosatetraenoic acid (20-HETE) derived from arachidonic acid (AA) by CYP4A in endotoxaemic rats. The aim of this study was to investigate the effects of piroxicam, a preferential COX-1 inhibitor, on the endotoxin-induced changes in blood pressure, expression of COX-1, inducible COX (COX-2), CYP4A1, eNOS, iNOS and heat shock protein 90 (hsp90), and production of PGI(2), PGE(2), 20-HETE and NO. Injection of endotoxin (10 mg/kg, i.p.) to male Wistar rats caused a fall in blood pressure and an increase in heart rate associated with elevated renal 6-keto-PGF(1α) and PGE(2) levels as well as an increase in COX-2 protein expression. Endotoxin also caused an elevation in systemic and renal nitrite levels associated with increased renal iNOS protein expression. In contrast, systemic and renal 20-HETE levels and renal expression of eNOS, COX-1 and CYP4A1 were decreased in endotoxaemic rats. The effects of endotoxin, except for renal COX-1 and eNOS protein expression, were prevented by piroxicam (10 mg/kg, i.p.), given 1 hr after injection of endotoxin. Endotoxin did not change renal hsp90 protein expression. These data suggest that a decrease in the expression and activity of COX-2 and iNOS associated with an increase in CYP4A1 expression and 20-HETE synthesis contributes to the effect of piroxicam to prevent the hypotension during rat endotoxaemia.

  17. Aneuploidy as a mechanism for stress-induced liver adaptation.

    Science.gov (United States)

    Duncan, Andrew W; Hanlon Newell, Amy E; Bi, Weimin; Finegold, Milton J; Olson, Susan B; Beaudet, Arthur L; Grompe, Markus

    2012-09-01

    Over half of the mature hepatocytes in mice and humans are aneuploid and yet retain full ability to undergo mitosis. This observation has raised the question of whether this unusual somatic genetic variation evolved as an adaptive mechanism in response to hepatic injury. According to this model, hepatotoxic insults select for hepatocytes with specific numerical chromosome abnormalities, rendering them differentially resistant to injury. To test this hypothesis, we utilized a strain of mice heterozygous for a mutation in the homogentisic acid dioxygenase (Hgd) gene located on chromosome 16. Loss of the remaining Hgd allele protects from fumarylacetoacetate hydrolase (Fah) deficiency, a genetic liver disease model. When adult mice heterozygous for Hgd and lacking Fah were exposed to chronic liver damage, injury-resistant nodules consisting of Hgd-null hepatocytes rapidly emerged. To determine whether aneuploidy played a role in this phenomenon, array comparative genomic hybridization (aCGH) and metaphase karyotyping were performed. Strikingly, loss of chromosome 16 was dramatically enriched in all mice that became completely resistant to tyrosinemia-induced hepatic injury. The frequency of chromosome 16-specific aneuploidy was approximately 50%. This result indicates that selection of a specific aneuploid karyotype can result in the adaptation of hepatocytes to chronic liver injury. The extent to which aneuploidy promotes hepatic adaptation in humans remains under investigation.

  18. Hypercholesterolemia Induces Differentiation of Regulatory T Cells in the Liver.

    Science.gov (United States)

    Mailer, Reiner K W; Gisterå, Anton; Polyzos, Konstantinos A; Ketelhuth, Daniel F J; Hansson, Göran K

    2017-05-26

    The liver is the central organ that responds to dietary cholesterol intake and facilitates the release and clearance of lipoprotein particles. Persistent hypercholesterolemia leads to immune responses against lipoprotein particles that drive atherosclerosis. However, the effect of hypercholesterolemia on hepatic T-cell differentiation remains unknown. To investigate hepatic T-cell subsets upon hypercholesterolemia. We observed that hypercholesterolemia elevated the intrahepatic regulatory T (Treg) cell population and increased the expression of transforming growth factor-β1 in the liver. Adoptive transfer experiments revealed that intrahepatically differentiated Treg cells relocated to the inflamed aorta in atherosclerosis-prone low-density lipoprotein receptor deficient (Ldlr(-/-)) mice. Moreover, hypercholesterolemia induced the differentiation of intrahepatic, but not intrasplenic, Th17 cells in wild-type mice, whereas the disrupted liver homeostasis in hypercholesterolemic Ldlr(-/-) mice led to intrahepatic Th1 cell differentiation and CD11b(+)CD11c(+) leukocyte accumulation. Our results elucidate a new mechanism that controls intrahepatic T-cell differentiation during atherosclerosis development and indicates that intrahepatically differentiated T cells contribute to the CD4(+) T-cell pool in the atherosclerotic aorta. © 2017 American Heart Association, Inc.

  19. Quercetin Reverses Rat Liver Preneoplastic Lesions Induced by Chemical Carcinogenesis

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    Gabriela Carrasco-Torres

    2017-01-01

    Full Text Available Quercetin is a flavonoid widely studied as a chemopreventive agent in different types of cancer. Previously, we reported that quercetin has a chemopreventive effect on the liver-induced preneoplastic lesions in rats. Here, we evaluated if quercetin was able not only to prevent but also to reverse rat liver preneoplastic lesions. We used the modified resistant hepatocyte model (MRHM to evaluate this possibility. Treatment with quercetin was used 15 days after the induction of preneoplastic lesions. We found that quercetin reverses the number of preneoplastic lesions and their areas. Our results showed that quercetin downregulates the expression of EGFR and modulates this signaling pathway in spite of the activated status of EGFR as detected by the upregulation of this receptor, with respect to that observed in control rats. Besides, quercetin affects the phosphorylation status of Src-1, STAT5, and Sp-1. The better status of the liver after the treatment with quercetin could also be confirmed by the recovery in the expression of IGF-1. In conclusion, we suggest that quercetin reversed preneoplastic lesions by EGFR modulation and the activation state of Src, STAT5, and Sp1, so as the basal IGF-1.

  20. HIV-Antiretroviral Therapy Induced Liver, Gastrointestinal, and Pancreatic Injury

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    Manuela G. Neuman

    2012-01-01

    Full Text Available The present paper describes possible connections between antiretroviral therapies (ARTs used to treat human immunodeficiency virus (HIV infection and adverse drug reactions (ADRs encountered predominantly in the liver, including hypersensitivity syndrome reactions, as well as throughout the gastrointestinal system, including the pancreas. Highly active antiretroviral therapy (HAART has a positive influence on the quality of life and longevity in HIV patients, substantially reducing morbidity and mortality in this population. However, HAART produces a spectrum of ADRs. Alcohol consumption can interact with HAART as well as other pharmaceutical agents used for the prevention of opportunistic infections such as pneumonia and tuberculosis. Other coinfections that occur in HIV, such as hepatitis viruses B or C, cytomegalovirus, or herpes simplex virus, further complicate the etiology of HAART-induced ADRs. The aspect of liver pathology including liver structure and function has received little attention and deserves further evaluation. The materials used provide a data-supported approach. They are based on systematic review and analysis of recently published world literature (MedLine search and the experience of the authors in the specified topic. We conclude that therapeutic and drug monitoring of ART, using laboratory identification of phenotypic susceptibilities, drug interactions with other medications, drug interactions with herbal medicines, and alcohol intake might enable a safer use of this medication.

  1. Gamma-Glutamylcysteine Ethyl Ester Protects against Cyclophosphamide-Induced Liver Injury and Hematologic Alterations via Upregulation of PPARγ and Attenuation of Oxidative Stress, Inflammation, and Apoptosis

    Science.gov (United States)

    Alqahtani, Sultan

    2016-01-01

    Gamma-glutamylcysteine ethyl ester (GCEE) is a precursor of glutathione (GSH) with promising hepatoprotective effects. This investigation aimed to evaluate the hepatoprotective effects of GCEE against cyclophosphamide- (CP-) induced toxicity, pointing to the possible role of peroxisome proliferator activated receptor gamma (PPARγ). Wistar rats were given GCEE two weeks prior to CP. Five days after CP administration, animals were sacrificed and samples were collected. Pretreatment with GCEE significantly alleviated CP-induced liver injury by reducing serum aminotransferases, increasing albumin, and preventing histopathological and hematological alterations. GCEE suppressed lipid peroxidation and nitric oxide production and restored GSH and enzymatic antioxidants in the liver, which were associated with downregulation of COX-2, iNOS, and NF-κB. In addition, CP administration significantly increased serum proinflammatory cytokines and the expression of liver caspase-3 and BAX, an effect that was reversed by GCEE. CP-induced rats showed significant downregulation of PPARγ which was markedly upregulated by GCEE treatment. These data demonstrated that pretreatment with GCEE protected against CP-induced hepatotoxicity, possibly by activating PPARγ, preventing GSH depletion, and attenuating oxidative stress, inflammation, and apoptosis. Our findings point to the role of PPARγ and suggest that GCEE might be a promising agent for the prevention of CP-induced liver injury. PMID:28074115

  2. Bone disorders in experimentally induced liver disease in growing rats

    Institute of Scientific and Technical Information of China (English)

    Viktória Ferencz; Ferenc Szalay; Csaba Horváth; Béla Kári; János Gaál; Szilvia Mészáros; Zsuzsanna Wolf; Dalma Hegedüs; Andrea Horváth; Anikó Folhoffer

    2005-01-01

    AIM: To investigate the change of bone parameters in a new model of experimentally induced liver cirrhosis and hepatocellular carcinoma (HCC) in growing rats.METHODS: Fischer-344 rats (n = 55) were used. Carbon tetrachloride (CCl4), phenobarbital (PB), and a single diethylnitrosamine (DEN) injection were used. Animals were killed at wk 8 and 16. Bone mineral content, femoral length, cortical index (quotient of cortical thickness and whole diameter) and ultimate bending load (Fmax)of the femora were determined. The results in animals treated with DEN+PB+CCl4 (DPC, n = 21) were compared to those in untreated animals (UNT,n = 14) and in control group treated only with DEN+PB (DP, n = 20).RESULTS: Fatty liver and cirrhosis developed in each DPC-treated rat at wk 8 and HCC was presented at wk 16. No skeletal changes were found in this group at wk 8,but each parameter was lower (P<0.05 for each) at wk 16 in comparison to the control group. Neither fatty liver nor cirrhosis was observed in DP-treated animals at any time point. Femoral length and Fmax values were higher (P<0.05 for both) in DP-treated animals at wk 8 compared to the UNT controls. However, no difference was found at wk 16.CONCLUSION: Experimental liver cirrhosis and HCC are accompanied with inhibited skeletal growth, reduced bone mass, and decreased mechanical resistance in growing rats. Our results are in concordance with the data of other studies using different animal models. A novel finding is the transiently accelerated skeletal growth and bone strength after a 8-wk long phenobarbital treatment following diethylnitrosamine injection.

  3. Inhibition of inducible nitric oxide synthase expression and nitric oxide production in plateau pika (Ochotona curzoniae) at high altitude on Qinghai-Tibet Plateau.

    Science.gov (United States)

    Xie, Ling; Zhang, Xuze; Qi, Delin; Guo, Xinyi; Pang, Bo; Du, Yurong; Zou, Xiaoyan; Guo, Songchang; Zhao, Xinquan

    2014-04-30

    Nitric oxide (NO), a potent vasodilator, plays an important role in preventing hypoxia induced pulmonary hypertension. Endogenous NO is synthesized by nitric oxide synthases (NOSs) from l-arginine. In mammals, three different NOSs have been identified, including neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS). Plateau pika (Ochotona curzoniae) is a typical hypoxia tolerant mammal that lives at 3000-5000 m above sea level on the Qinghai-Tibet Plateau. The aim of this study was to investigate whether NOS expression and NO production are regulated by chronic hypoxia in plateau pika. Quantitative real-time PCR and western blot analyses were conducted to quantify relative abundances of iNOS and eNOS transcripts and proteins in the lung tissues of plateau pikas at different altitudes (4550, 3950 and 3200 m). Plasma NO metabolites, nitrite/nitrate (NO(x)⁻) levels were also examined by Ion chromatography to determine the correlation between NO production and altitude level. The results revealed that iNOS transcript levels were significantly lower in animals at high altitudes (decreased by 53% and 57% at altitude of 3950 and 4550 m compared with that at 3200 m). Similar trends in iNOS protein abundances were observed (26% and 41% at 3950 and 4550 m comparing with at 3200 m). There were no significant differences in eNOS mRNA and protein levels in the pika lungs among different altitudes. The plasma NO(x)⁻ levels of the plateau pikas at high altitudes significantly decreased (1.65±0.19 μg/mL at 3200 m to 0.44±0.03 μg/mL at 3950 m and 0.24±0.01 μg/mL at 4550 m). This is the first evidence describing the effects of chronic hypoxia on NOS expression and NO levels in the plateau pika in high altitude adaptation. We conclude that iNOS expression and NO production are suppressed at high altitudes, and the lower NO concentration at high altitudes may serve crucial roles for helping the plateau pika to survive at hypoxic environment.

  4. Inducible Nitric Oxide Synthase Promoter Haplotypes and Residential Traffic-Related Air Pollution Jointly Influence Exhaled Nitric Oxide Level in Children.

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    Muhammad T Salam

    Full Text Available Exhaled nitric oxide (FeNO, a biomarker of airway inflammation, predicts asthma risk in children. We previously found that the promoter haplotypes in inducible nitric oxide synthase (NOS2 and exposure to residential traffic independently influence FeNO level. Because NOS2 is inducible by environmental exposures such as traffic-related exposure, we tested the hypothesis that common NOS2 promoter haplotypes modulate the relationship between residential traffic-related exposure and FeNO level in children.In a cross-sectional population-based study, subjects (N = 2,457; 7-11 year-old were Hispanic and non-Hispanic white children who participated in the Southern California Children's Health Study and had FeNO measurements. For residential traffic, lengths of local roads within circular buffers (50m, 100m and 200m radii around homes around the subjects' homes were estimated using geographic information system (GIS methods. We interrogated the two most common NOS2 promoter haplotypes that were found to affect FeNO level.The relationship between local road lengths within 100m and 200m circular buffers and FeNO level varied significantly by one of the NOS2 promoter haplotypes (P-values for interaction between road length and NOS2 promoter haplotype = 0.02 and 0.03, respectively. In children who had ≤250m of local road lengths within 100m buffer around their homes, those with two copies of the haplotype had significantly lower FeNO (adjusted geometric mean = 11.74ppb; 95% confidence intervals (CI: 9.99 to 13.80 than those with no copies (adjusted geometric mean = 15.28ppb; 95% CI: 14.04 to 16.63 with statistically significant trend of lower FeNO level with increasing number of haplotype copy (P-value for trend = 0.002. In contrast, among children who had >250m of local road lengths within 100m buffer, FeNO level did not significantly differ by the haplotype copy-number (P-value for trend = 0.34. Similar interactive effects of this haplotype and local

  5. Inducible nitric-oxide synthase plays a minimal role in lymphocytic choriomeningitis virus-induced, T cell-mediated protective immunity and immunopathology

    DEFF Research Database (Denmark)

    Bartholdy, C; Nansen, A; Christensen, Jeanette Erbo;

    1999-01-01

    -mediated immune response was found to be unaltered in iNOS-deficient mice compared with wild-type C57BL/6 mice, and LCMV- induced general immunosuppression was equally pronounced in both strains. In vivo analysis revealed identical kinetics of virus clearance, as well as unaltered clinical severity of systemic......By using mice with a targetted disruption in the gene encoding inducible nitric-oxide synthase (iNOS), we have studied the role of nitric oxide (NO) in lymphocytic choriomeningitis virus (LCMV)-induced, T cell-mediated protective immunity and immunopathology. The afferent phase of the T cell....... This might suggest a role of NO in regulating vascular reactivity in the context of T cell-mediated inflammation. In conclusion, these findings indicate a minimal role for iNOS/NO in the host response to LCMV. Except for a reduced local oedema in the knockout mice, iNOS/NO seems to be redundant...

  6. Tacrolimus modulates liver and pancreas nitric oxide synthetase and heme-oxygenase isoforms and cytokine production after endotoxemia.

    Science.gov (United States)

    Balibrea, José M; García-Martín, M Cruz; Cuesta-Sancho, Sara; Olmedilla, Yoko; Arias-Díaz, Javier; Fernández-Sevilla, Elena; Vara, Elena; Balibrea, José L

    2011-03-15

    Cytoprotective effects of tacrolimus are due to its unspecific anti-inflammatory and anti-oxidant properties. Neither the exact mechanisms nor if there is any organ-specificity or dose-dependent response have not been yet elucidated. Our aim was to evaluate the effect of tacrolimus on oxidative stress and mediator production in liver and pancreatic tissue secondary to endotoxemia. Wistar rats were pretreated with intraperitoneal injection of tacrolimus (0.07, 0.15, and 0.3mg/kg) 24h before Escherichia coli LPS was administrated. Animals were sacrificed 24h after LPS administration and iNOS, eNOS, and nNOS and type 1 and 2 heme-oxygenase (HO) expression were measured. TNF-α and IL-1 tissue expression and plasmatic NO, CO, TNF-α, and IL-1 were also determined. LPS exposure increased iNOS expression in both organs, eNOS did not show variations and liver nNOS expression was significantly lower. Tacrolimus diminished both pancreas and liver iNOS and nNOS expression. Both liver and pancreatic eNOS expression augmented when tacrolimus was administrated. High doses of tacrolimus were correlated with ameliorated liver HO-1 plus HO-2 and pancreas HO-1 expression after LPS stimulation. Tacrolimus treatment diminished TNF-α but not IL-1 expression increase after LPS challenge in hepatic tissue. Pancreatic TNF-α and IL-1 values diminished partially when high doses were employed. Plasmatic NO, CO, TNF-α, and IL-1 concentrations increase after LPS challenge was diminished when highest doses of tacrolimus were given. In conclusion, tacrolimus exerts a protective effect on commonly observed harmful phenomena after LPS stimulation by modulating liver and pancreas oxidative enzyme expression and cytokine production.

  7. Role of Nitric Oxide in Shiga Toxin-2-Induced Premature Delivery of Dead Fetuses in Rats

    Science.gov (United States)

    Burdet, Juliana; Zotta, Elsa; Cella, Maximiliano; Franchi, Ana M.; Ibarra, Cristina

    2010-01-01

    Shiga toxin-producing Escherichia coli (STEC) infections could be one of the causes of fetal morbimortality in pregnant women. The main virulence factors of STEC are Shiga toxin type 1 and/or 2 (Stx1, Stx2). We previously reported that intraperitoneal (i.p.) injection of rats in the late stage of pregnancy with culture supernatant from recombinant E. coli expressing Stx2 and containing lipopolysaccharide (LPS) induces premature delivery of dead fetuses. It has been reported that LPS may combine with Stx2 to facilitate vascular injury, which may in turn lead to an overproduction of nitric oxide (NO). The aim of this study was to evaluate whether NO is involved in the effects of Stx2 on pregnancy. Pregnant rats were i.p. injected with culture supernatant from recombinant E. coli containing Stx2 and LPS (sStx2) on day 15 of gestation. In addition, some rats were injected with aminoguanidine (AG), an inducible isoform inhibitor of NO synthase (iNOS), 24 h before and 4 h after sStx2 injection. NO production was measured by NOS activity and iNOS expression by Western blot analysis. A significant increase in NO production and a high iNOS expression was observed in placental tissues from rats injected with sStx2 containing 0.7 ng and 2 ng Stx2/g body weight and killed 12 h after injection. AG caused a significant reduction of sStx2 effects on the feto-maternal unit, but did not prevent premature delivery. Placental tissues from rats treated with AG and sStx2 presented normal histology that was indistinguishable from the controls. Our results reveal that Stx2-induced placental damage and fetus mortality is mediated by an increase in NO production and that AG is able to completely reverse the Stx2 damages in placental tissues, but not to prevent premature delivery, thus suggesting other mechanisms not yet determined could be involved. PMID:21206910

  8. Protective actions of estrogen on angiotensin II-induced hypertension: role of central nitric oxide.

    Science.gov (United States)

    Xue, Baojian; Singh, Minati; Guo, Fang; Hay, Meredith; Johnson, Alan Kim

    2009-11-01

    The present study tested the hypotheses that 1) nitric oxide (NO) is involved in attenuated responses to ANG II in female mice, and 2) there is differential expression of neuronal NO synthase (nNOS) in the subfornical organ (SFO) and paraventricular nucleus (PVN) in response to systemic infusions of ANG II in males vs. females. Aortic blood pressure (BP) was measured in conscious mice with telemetry implants. N(G)-nitro-l-arginine methyl ester (l-NAME; 100 microg x kg(.-1)day(-1)), an inhibitor of NOS, was administrated into the lateral cerebral ventricle for 14 days before and during ANG II pump implantation. Central infusion of l-NAME augmented the pressor effects of systemic ANG II in females (Delta21.5 + or - 2.2 vs. Delta9.2 + or - 1.5 mmHg) but not in males (Delta29.4 + or - 2.5 vs. Delta30.1 + or - 2.5 mmHg). Central administration of N(5)-(1-imino-3-butenyl)-l-ornithine (l-VNIO), a selective nNOS inhibitor, also significantly potentiated the increase in BP induced by ANG II in females (Delta17.5 + or - 3.2 vs. Delta9.2 + or - 1.5 mmHg). In gonadectomized mice, central l-NAME infusion did not affect the pressor response to ANG II in either males or females. Ganglionic blockade after ANG II infusion resulted in a greater reduction in BP in central l-NAME- or l-VNIO-treated females compared with control females. Western blot analysis of nNOS protein expression indicated that levels were approximately 12-fold higher in both the SFO and PVN of intact females compared with those in intact males. Seven days of ANG II treatment resulted in a further increase in nNOS protein expression only in intact females (PVN, to approximately 51-fold). Immunohistochemical studies revealed colocalization of nNOS and estrogen receptors in the SFO and PVN. These results suggest that NO attenuates the increase in BP induced by ANG II through reduced sympathetic outflow in females and that increased nNOS protein expression associated with the presence of female sex hormones plays a

  9. Monocyte-induced downregulation of nitric oxide synthase in cultured aortic endothelial cells.

    Science.gov (United States)

    Marczin, N; Antonov, A; Papapetropoulos, A; Munn, D H; Virmani, R; Kolodgie, F D; Gerrity, R; Catravas, J D

    1996-09-01

    Since endothelium-dependent vasodilation is altered in atherosclerosis and enhanced monocyte/endothelial interactions are implicated in early atherosclerosis, we evaluated the effects of monocytes on the endothelial nitric oxide (NO) pathway by estimating release of biologically active NO from cultured endothelial cells and levels of constitutive NO synthase (ecNOS). NO release was estimated in a short-term bioassay using endothelial cell-induced cGMP accumulation in vascular smooth muscle (SM) cells. Exposure of SM cells to porcine aortic endothelial cells (PAECs) and human aortic endothelial cells (HAECs) produced large increases in SM cGMP content; this increase was prevented by NG-nitro-L-arginine methyl ester, the inhibitor of endothelial NOS. Confluent monolayers of PAECs and HAECs cocultured with monocytes also stimulated SM cGMP formation; however, NO release from these cultures was attenuated in a coculture time (2 to 48 hours)- and monocyte concentration (20 to 200 x 10(3) per well)-dependent manner. This effect of monocyte adhesion appeared to be selective for NO release since other biochemical pathways, such as atriopeptin-and isoproterenol-induced cyclic nucleotide accumulation within the endothelial cells, were not altered by monocytes. The effects of adherent monocytes on NO release were mimicked by monocyte-derived cytokines tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 alpha. Furthermore, the conditioned medium of monocytes contained significant quantities of these cytokines. Conditioned medium, as well as monocytes physically separated from the endothelial cells, attenuated NO release, suggesting that soluble factors may mediate the effects of monocytes. An IL-1 beta neutralizing antibody fully prevented the NO dysfunction in response to directly adherent monocytes. Superoxide dismutase, catalase, 4,5-dihydroxy-1,3-benzene disulfonic acid (Tiron), and exogenous L-arginine failed to improve NO release, suggesting that oxidant stress-induced

  10. Candidemia-induced pediatric sepsis and its association with free radicals, nitric oxide, and cytokine level in host.

    Science.gov (United States)

    Kumar, Dharmendra; Kumar, Abhai; Singh, Smita; Tilak, Ragini

    2015-04-01

    Candida species has become the seventh most frequent causal microorganisms of nosocomial sepsis. Prematurity and low birth weights are strongly associated with the development of neonatal nosocomial bloodstream infections. Candida albicans has been the species most often associated with neonatal infections, but recently, there has been a changing pattern in the isolates recovered from neonates with invasive candidiasis, which poses resistance to the existing class of azoles such as fluconazole antifungals along with cross resistance to newer triazoles, which results in a therapeutic challenge in invasive fungal infections causing high incidence of mortality. Candida species was isolated from blood of neonates and children younger than 15 years admitted to hospital and susceptible for Candida-induced sepsis. Polymerase chain reaction-based identification and confirmation of individual Candida species were done using DNA sequencing. Antibiotic susceptibility assay and resistance pattern for fluconazole, voriconazole, and amphotericin were done for all the isolates. Furthermore, the change in free radical, cytokine release, and nitric oxide synthase expression and nitric oxide release from polymorphonuclear leukocytes isolated from control and pediatric sepsis cases were also performed. The present study probably for the first time reports the change in increasing incidence of nonalbicans Candida-induced sepsis in neonates and children admitted to the intensive care unit of hospital, and current antibiotics load posing resistance for antifungal treatment strategy and provide serious threats in future treatment. The increase in free radicals in polymorphonuclear leukocytes and increase in expression of nitric oxide synthase expression and nitric oxide release in Candida-infected pediatric sepsis cases underlie the role of host factor in dissemination and invasiveness of infection from exogenous sources and pathogenesis of systemic inflammation during sepsis. Copyright

  11. Role for neuronal nitric-oxide synthase in cannabinoid-induced neurogenesis.

    Science.gov (United States)

    Kim, Sun Hee; Won, Seok Joon; Mao, Xiao Ou; Ledent, Catherine; Jin, Kunlin; Greenberg, David A

    2006-10-01

    Cannabinoids, acting through the CB1 cannabinoid receptor (CB1R), protect the brain against ischemia and related forms of injury. This may involve inhibiting the neurotoxicity of endogenous excitatory amino acids and downstream effectors, such as nitric oxide (NO). Cannabinoids also stimulate neurogenesis in the adult brain through activation of CB1R. Because NO has been implicated in neurogenesis, we investigated whether cannabinoid-induced neurogenesis, like cannabinoid neuroprotection, might be mediated through alterations in NO production. Accordingly, we measured neurogenesis in dentate gyrus (DG) and subventricular zone (SVZ) of CB1R-knockout (KO) and wild-type mice, some of whom were treated with the cannabinoid agonist R(+)-Win 55212-2 [(+)-[2,3-dihydro-5-methyl-3-[(morpholinyl)methyl]pyrrolo[1,2,3-de]-1,4-benzoxazin-yl]-(1-naphthalenyl)methanone] or the NO synthase (NOS) inhibitor 7-nitroindazole (7-NI). NOS activity was increased by approximately 25%, whereas bromodeoxyuridine (BrdU) labeling of newborn cells in DG and SVZ was reduced by approximately 50% in CB1R-KO compared with wild-type mice. 7-NI increased BrdU labeling in both DG and SVZ and to a greater extent in CB1R-KO than in wild-type mice. In addition, R(+)-Win 55212-2 and 7-NI enhanced BrdU incorporation into neuron-enriched cerebral cortical cultures to a similar maximal extent and in nonadditive fashion, consistent with a shared mechanism of action. Double-label confocal microscopy showed coexpression of BrdU and the neuronal lineage marker doublecortin (Dcx) in DG and SVZ of untreated and 7-NI-treated CB1R-KO mice, and 7-NI increased the number of Dcx- and BrdU/Dcx-immunoreactive cells in SVZ and DG. Thus, cannabinoids appear to stimulate adult neurogenesis by opposing the antineurogenic effect of NO.

  12. Croton schiedeanus Schltd prevents experimental hypertension in rats induced by nitric oxide deficit

    Directory of Open Access Journals (Sweden)

    María Teresa Páez

    2013-12-01

    Full Text Available Croton schiedeanus Schltd (N.V.: "almizclillo" is a plant used in traditional medicine as an antihypertensive in Colombia. It contains flavonoid, diterpenoid and fenilbutanoid metabolites that have vasodilatation effects linked to the NO/cGMP pathway. This work aimed to assess the capacity of a 96% EtOH extract to prevent the hypertension induced by nitric oxide (NO deficiency in rats. The NO synthase inhibitor L-NAME (10 mg/kg/d, i.p was administered during five weeks to three groups of rats (6-7 animals: C. Schiedeanus (200 mg/kg/d, p.o, enalapril (reference, 10 mg/kg/d, p.o and vehicle (control: olive oil 1 ml/kg/d, p.o. In addition, the blank group received only vehicle. The arterial blood pressure (BP and heart rate (HR were measured daily for six weeks. After sacrificing the animals, the aortic rings were isolated, contraction was triggered with phenylephrine (PE 10-6 M and relaxant responses were achieved with cumulative concentrations of acetylcholine (ACh, 10-10 - 10-4 M. L-NAME increased the systolic arterial pressure in the control group, attaining mean values of 131 mm Hg at week 5, whereas the C. schiedeanus, enalapril and blank groups maintained blood pressure under 100 mm Hg. The capacity of PE to contract aortic rings was greater in the C. schiedeanus, enalapril and blank groups than in the control group (2157, 2005, 1910 and 1646 mg, respectively. The pEC50 values for ACh were as follows: C. Schiedeanus (6.89 >enalapril (6.39 > blank (5.68 > control (5.09. These results give support to C. Schiedeanus as a natural antihypertensive source.

  13. Participation of neuronal nitric oxide synthase in experimental neuropathic pain induced by sciatic nerve transection

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    M. Chacur

    2010-04-01

    Full Text Available Nerve injury leads to a neuropathic pain state that results from central sensitization. This phenomenom is mediated by NMDA receptors and may involve the production of nitric oxide (NO. In this study, we investigated the expression of the neuronal isoform of NO synthase (nNOS in the spinal cord of 3-month-old male, Wistar rats after sciatic nerve transection (SNT. Our attention was focused on the dorsal part of L3-L5 segments receiving sensory inputs from the sciatic nerve. SNT resulted in the development of neuropathic pain symptoms confirmed by evaluating mechanical hyperalgesia (Randall and Selitto test and allodynia (von Frey hair test. Control animals did not present any alteration (sham-animals. The selective inhibitor of nNOS, 7-nitroindazole (0.2 and 2 µg in 50 µL, blocked hyperalgesia and allodynia induced by SNT. Immunohistochemical analysis showed that nNOS was increased (48% by day 30 in the lumbar spinal cord after SNT. This increase was observed near the central canal (Rexed’s lamina X and also in lamina I-IV of the dorsal horn. Real-time PCR results indicated an increase of nNOS mRNA detected from 1 to 30 days after SNT, with the highest increase observed 1 day after injury (1469%. Immunoblotting confirmed the increase of nNOS in the spinal cord between 1 and 15 days post-lesion (20%, reaching the greatest increase (60% 30 days after surgery. The present findings demonstrate an increase of nNOS after peripheral nerve injury that may contribute to the increase of NO production observed after peripheral neuropathy.

  14. Nitric oxide induces stomatal closure and enhances the adaptive plant responses against drought stress.

    Science.gov (United States)

    García-Mata, C; García Mata, C; Lamattina, L

    2001-07-01

    Nitric oxide (NO) is a very active molecule involved in many and diverse biological pathways where it has proved to be protective against damages provoked by oxidative stress conditions. In this work, we studied the effect of two NO donors, sodium nitroprusside (SNP) and S-nitroso-N-acetylpenicillamine SNP-treated on the response of wheat (Triticum aestivum) to water stress conditions. After 2 and 3 h of drought, detached wheat leaves pretreated with 150 microM SNP retained up to 15% more water than those pretreated with water or NO(2)(-)/NO(3)(-). The effect of SNP treatment on water retention was also found in wheat seedlings after 7 d of drought. These results were consistent with a 20% decrease in the transpiration rate of SNP-treated detached wheat leaves for the same analyzed time. In parallel experiments, NO was also able to induce a 35%, 30%, and 65% of stomatal closure in three different species, Tradescantia sp. (monocotyledonous) and two dicotyledonous, Salpichroa organifolia and fava bean (Vicia faba), respectively. In SNP-treated leaves of Tradescantia sp., the stomatal closure was correlated with a 10% increase on RWC. Ion leakage, a cell injury index, was 25% lower in SNP-treated wheat leaves compared with control ones after the recovery period. Carboxy-PTIO (2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), a specific NO scavenger, reverted SNP action by restoring the transpiration rate, stomatal aperture, and the ion leakage to the level found in untreated leaves. Northern-blot analysis showed that SNP-treated wheat leaves display a 2-fold accumulation of a group three late embryogenesis abundant transcript with respect to control leaves both after 2 and 4 h of drought periods. All together, these results suggest that the exogenous application of NO donors might confer an increased tolerance to severe drought stress conditions in plants.

  15. Anandamide induces sperm release from oviductal epithelia through nitric oxide pathway in bovines.

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    Claudia Osycka-Salut

    Full Text Available Mammalian spermatozoa are not able to fertilize an egg immediately upon ejaculation. They acquire this ability during their transit through the female genital tract in a process known as capacitation. The mammalian oviduct acts as a functional sperm reservoir providing a suitable environment that allows the maintenance of sperm fertilization competence until ovulation occurs. After ovulation, spermatozoa are gradually released from the oviductal reservoir in the caudal isthmus and ascend to the site of fertilization. Capacitating-related changes in sperm plasma membrane seem to be responsible for sperm release from oviductal epithelium. Anandamide is a lipid mediator that participates in the regulation of several female and male reproductive functions. Previously we have demonstrated that anandamide was capable to release spermatozoa from oviductal epithelia by induction of sperm capacitation in bovines. In the present work we studied whether anandamide might exert its effect by activating the nitric oxide (NO pathway since this molecule has been described as a capacitating agent in spermatozoa from different species. First, we demonstrated that 1 µM NOC-18, a NO donor, and 10 mM L-Arginine, NO synthase substrate, induced the release of spermatozoa from the oviductal epithelia. Then, we observed that the anandamide effect on sperm oviduct interaction was reversed by the addition of 1 µM L-NAME, a NO synthase inhibitor, or 30 µg/ml Hemoglobin, a NO scavenger. We also demonstrated that the induction of bull sperm capacitation by nanomolar concentrations of R(+-methanandamide or anandamide was inhibited by adding L-NAME or Hemoglobin. To study whether anandamide is able to produce NO, we measured this compound in both sperm and oviductal cells. We observed that anandamide increased the levels of NO in spermatozoa, but not in oviductal cells. These findings suggest that anandamide regulates the sperm release from oviductal epithelia probably by

  16. Leptin induces nitric oxide-mediated inhibition of lipolysis and glyceroneogenesis in rat white adipose tissue.

    Science.gov (United States)

    Niang, Fatoumata; Benelli, Chantal; Ribière, Catherine; Collinet, Martine; Mehebik-Mojaat, Nadia; Penot, Graziella; Forest, Claude; Jaubert, Anne-Marie

    2011-01-01

    Leptin is secreted by white adipose tissue (WAT) and induces lipolysis and nonesterified fatty acid (NEFA) oxidation. During lipolysis, NEFA efflux is the result of triglyceride breakdown, NEFA oxidation, and re-esterification via glyceroneogenesis. Leptin's effects on glyceroneogenesis remain unexplored. We investigated the effect of a long-term treatment with leptin at a physiological concentration (10 μg/L) on lipolysis and glyceroneogenesis in WAT explants and analyzed the underlying mechanisms. Exposure of rat WAT explants to leptin for 2 h resulted in increased NEFA and glycerol efflux. However, a longer treatment with leptin (18 h) did not affect NEFA release and reduced glycerol output. RT-qPCR showed that leptin significantly downregulated the hormone-sensitive lipase (HSL), cytosolic phosphoenolpyruvate carboxykinase (Pck1), and PPARγ genes. In agreement with its effect on mRNA, leptin also decreased the levels of PEPCK-C and HSL proteins. Glyceroneogenesis, monitored by [1-(14) C] pyruvate incorporation into lipids, was reduced. Because leptin increases nitric oxide (NO) production in adipocytes, we explored the role of NO in the leptin signaling pathway. Pretreatment of explants with the NO synthase inhibitor Nω-nitro-l-arginine methyl ester eliminated the effect of leptin on lipolysis, glyceroneogenesis, and expression of the HSL, Pck1, and PPARγ genes. The NO donor S-nitroso-N-acetyl-DL penicillamine mimicked leptin effects, thus demonstrating the role of NO in these pathways. The inverse time-dependent action of leptin on WAT is consistent with a process that limits NEFA re-esterification and energy storage while reducing glycerol release, thus preventing hypertriglyceridemia.

  17. Hepatoprotective Effect of Fermented Soybean (Nutrient Enriched Soybean Tempeh against Alcohol-Induced Liver Damage in Mice

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    Hamidah Mohd Yusof

    2013-01-01

    Full Text Available Recently, soybean tempeh has received great attention due to many advantages such as higher nutritional value, lower production cost, and shorter fermentation time. In this study, the in vivo hepatoprotective and antioxidant effects of nutrient enriched soybean tempeh (NESTE were determined. NESTE fermentation process which involved anaerobic incubation was previously proclaimed to increase the content of amino acids and antioxidant properties remarkably. The evaluation of histological sections, serum biochemical markers (aspartate aminotransferase (AST, alanine aminotransferase (ALT, and cholesterol and triglycerides (TG, liver immune response level (nitric oxide (NO and liver antioxidant level (superoxide dismutase (SOD, ferric reducing antioxidant power (FRAP, and malondialdehyde (MDA was conducted in order to compare the effects of nonfermented soybean extract (SBE and fermented soybean extract (NESTE on alcohol-induced liver damage in mice. Results demonstrated that 1000 mg/kg of NESTE can significantly reduce the levels of AST, ALT, cholesterol, TG, MDA, and NO. On the other hand, it also raised the level of SOD and FRAP. Furthermore, the histological examination on 1000 mg/kg NESTE treatment group showed that this extract was capable of recovering the damaged hepatocytes to their normal structures. Thus, it can be concluded that NESTE produced through fermentation process was able to enhance hepatoprotective and antioxidant effects in vivo.

  18. Protective effects of red wine polyphenols and grape-seed proanthocyanidin extract on acetaminophen-induced liver injury

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    El-Sayed M. El-Sayed

    2014-11-01

    Full Text Available The present study was designed to examine the potential protective effects of red wine polyphenols (RWPs and grape seed proanthocyanidin extract (GSPE against acetaminophen-induced hepatotoxicity. Silymarin was used as a standard reference hepatoprotective agent. A single dose of acetaminophen (800 mg/kg, injected intraperitoneally to male rats, caused a significant increase in serum ALT, AST, alkaline phosphatase (ALP, bilirubin, total cholesterol (TC, triglycerides(TG, tumor necrosis factor alpha (TNF-α, and liver contents of thiobarbituric acid reactive substances (TBARS measured as malondialdehyde (MDA and nitric oxide (NO with significant decrease in serum albumin, HDL cholesterol, reduced glutathione (GSH and hepatic activities of catalase (CAT, superoxide dismutase (SOD and caspase-3 in liver tissue as compared with the control group. On the other hand, administration of each of GSPE (100 mg/kg/day, p.o., RWPs (40 mg/kg/day, p.o. and silymarin (100 mg/kg/day, p.o. for 15 consecutive days significantly ameliorated the liver injury which confirmed by the histopathological examination. It was concluded that RWPs and GSPE showed protective effects against acute acetaminophen hepatotoxicity where RWPs were more effective than GSPE; most probably through their antioxidant, anti-inflammatory and anti-apoptotic effects.

  19. The effect of thalidomide on ethanol-induced gastric mucosal damage in mice: involvement of inflammatory cytokines and nitric oxide.

    Science.gov (United States)

    Amirshahrokhi, Keyvan; Khalili, Ali-Reza

    2015-01-01

    Excessive ethanol ingestion causes gastric mucosal damage through the inflammatory and oxidative processes. The present study was aimed to evaluate the protective effect of thalidomide on ethanol-induced gastric mucosal damage in mice. The animals were pretreated with vehicle or thalidomide (30 or 60 mg/kg, orally), and one hour later, the gastric mucosal injury was induced by oral administration of acidified ethanol. The animals were euthanized one hour after ethanol ingestion, and gastric tissues were collected to biochemical analyzes. The gastric mucosal lesions were assessed by macroscopic and histopathological examinations. The results showed that treatment of mice with thalidomide prior to the administration of ethanol dose-dependently reduced the gastric ulcer index. Thalidomide pretreatment significantly reduced the levels of pro-inflammatory cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6], malondialdehyde (MDA) and myeloperoxidase (MPO) activity. In addition, thalidomide significantly inhibited ethanol-induced nitric oxide (NO) overproduction in gastric tissue. Histological observations showed that ethanol-induced gastric mucosal damage was attenuated by thalidomide pretreatment. It seems that thalidomide as an anti-inflammatory agent may have a protective effect against alcohol-induced mucosal damage by inhibition of neutrophil infiltration and reducing the production of nitric oxide and inflammatory cytokines in gastric tissue.

  20. Low-dose ribavirin treatments attenuate neuroinflammatory activation of BV-2 Cells by interfering with inducible nitric oxide synthase.

    Science.gov (United States)

    Bozic, Iva; Savic, Danijela; Jovanovic, Marija; Bjelobaba, Ivana; Laketa, Danijela; Nedeljkovic, Nadezda; Stojiljkovic, Mirjana; Pekovic, Sanja; Lavrnja, Irena

    2015-01-01

    Microglia play a key role in defending central nervous system from various internal and external threats. However, their excessive and/or chronic activation is associated with deleterious effects in a variety of neurodegenerative diseases. Previously, we have shown that ribavirin when applied in clinically relevant dosage (10 μM) modulates activated microglia in complex fashion inducing both anti- and proinflammatory effects, simultaneously causing cytotoxicity. Here, we examined potential of low-dose ribavirin (0.1 and 1 μM) to modulate activated BV-2 microglia. Morphological and functional activation of BV-2 cells was achieved with lipopolysaccharide (LPS) stimulation. Our results demonstrated that low-dose ribavirin did not induce cell death, while 10 μM ribavirin promoted LPS induced apoptosis. We determined that 1 μM ribavirin was equally efficient in deactivation of LPS induced morphological changes as 10 μM ribavirin treatment. Ribavirin showed halfway success in reducing markers of functional activation of microglia. Namely, none of the doses had effect on LPS triggered production of proinflammatory cytokine tumor necrosis factor alpha. On the other hand, low-dose ribavirin proved its effectiveness in reduction of another inflammatory mediator, nitric oxide, by inhibiting inducible form of nitric oxide synthase. Our results imply that low-dose ribavirin may alleviate nitrosative stress during neuroinflammation.

  1. Low-Dose Ribavirin Treatments Attenuate Neuroinflammatory Activation of BV-2 Cells by Interfering with Inducible Nitric Oxide Synthase

    Directory of Open Access Journals (Sweden)

    Iva Bozic

    2015-01-01

    Full Text Available Microglia play a key role in defending central nervous system from various internal and external threats. However, their excessive and/or chronic activation is associated with deleterious effects in a variety of neurodegenerative diseases. Previously, we have shown that ribavirin when applied in clinically relevant dosage (10 μM modulates activated microglia in complex fashion inducing both anti- and proinflammatory effects, simultaneously causing cytotoxicity. Here, we examined potential of low-dose ribavirin (0.1 and 1 μM to modulate activated BV-2 microglia. Morphological and functional activation of BV-2 cells was achieved with lipopolysaccharide (LPS stimulation. Our results demonstrated that low-dose ribavirin did not induce cell death, while 10 μM ribavirin promoted LPS induced apoptosis. We determined that 1 μM ribavirin was equally efficient in deactivation of LPS induced morphological changes as 10 μM ribavirin treatment. Ribavirin showed halfway success in reducing markers of functional activation of microglia. Namely, none of the doses had effect on LPS triggered production of proinflammatory cytokine tumor necrosis factor alpha. On the other hand, low-dose ribavirin proved its effectiveness in reduction of another inflammatory mediator, nitric oxide, by inhibiting inducible form of nitric oxide synthase. Our results imply that low-dose ribavirin may alleviate nitrosative stress during neuroinflammation.

  2. Nitric oxide contributes to cytokine-induced apoptosis in pancreatic beta cells via potentiation of JNK activity and inhibition of Akt

    DEFF Research Database (Denmark)

    Størling, J; Binzer, J; Andersson, Annica;

    2005-01-01

    Pro-inflammatory cytokines cause beta cell secretory dysfunction and apoptosis--a process implicated in the pathogenesis of type 1 diabetes. Cytokines induce the expression of inducible nitric oxide (NO) synthase (iNOS) leading to NO production. NO contributes to cytokine-induced apoptosis, but t...

  3. Protective effect of melatonin against liver injury in mice induced by Bacillus Calmette-Guerin plus lipopolysaccharide

    Institute of Scientific and Technical Information of China (English)

    Hua Wang; Wei Wei; Yu-Xian Shen; Chen Dong; Ling-Ling Zhang; Ni-Ping Wang; Li Yue; Shu-Yun Xu

    2004-01-01

    AIM: To investigate the effects and mechanisms of melatonin on immunological liver injury in mice.METHODS: A model of liver injury was induced by tail veininjection of Bacillus Calmette Guerin (BCG) and lipopolysaccharide(LPS) in mice. Kupffer cells and hepatocytes were isolatedand cultured according to a modified two-step collagenaseperfusion technique. Levels of alanine aminotransferase(ALT), aspartate aminotransferase (AST) and nitric oxide(NO), content of malondiadehyde (MDA), activity of superoxidedismutase (SOD), were measured by biochemical methods.Tumor necrosis factor-α (TNF-α) activity was determinedby RIA. Interleukin (IL)-1 activity was measured by thymocyte proliferation bioassay. Hepatic tissue sections were stained with hematoxylin and eosin and examined under a lightmicroscope.RESULTS: Immunological liver injury induced by BCG+LPSwas successfully duplicated. Serum transaminase (ALT,AST) activities were significantly decreased by melatonin(0.25, 1.0, 4.0 mg/kg bm). Meanwhile, MDA content was decreased and SOD in liver homogenates was upregulated.Furthermore, pro-inflammatory mediators (TNF-α, IL-1, NO)in serum and liver homogenates were significantly reduced by melatonin. Histological examination demonstrated that melatonin could attenuate the area and extent of necrosis,reduce the immigration of inflammatory cells. In in vitro experiment, TNF-α was inhibited at the concentrations of10-8-10-6 mol/L of melatonin, while IL-1 production of Kupffer cells induced by LPS (5 μg/mL) was decreased only at theconcentration of 10-6 mol/L of melatonin, but no effect onNO production was observed. Immunological liver injury model in vitro was established by incubating hepatocyteswith BCG- and LPS-induced Kupffer cells. Activities of ALT,TNF-α, IL-1, and MDA in supernatant were significantlyincreased. Melatonin had little effect on the level of ALT,but reduced the content of TNF-α and MDA at concentrationsof 10-7-10-5 mol/L and decreased the content of IL-1

  4. Nitric oxide-induced calcium release: activation of type 1 ryanodine receptor, a calcium release channel, through non-enzymatic posttranslational modification by nitric oxide

    Directory of Open Access Journals (Sweden)

    Sho eKakizawa

    2013-10-01

    Full Text Available Nitric oxide (NO is a typical gaseous messenger involved in a wide range of biological processes. In our classical knowledge, effects of NO are largely achieved by activation of soluble guanylyl cyclase to form cyclic guanosine-3’, 5’-monophosphate. However, emerging evidences have suggested another signaling mechanism mediated by NO: S-nitrosylation of target proteins.S-nitrosylation is a covalent addition of an NO group to a cysteine thiol/sulfhydryl (RSH, and categorized into non-enzymatic posttranslational modification of proteins, contrasted to enzymatic posttranslational modification of proteins, such as phosphorylation mediated by various protein kinases.Very recently, we found novel intracellular calcium (Ca2+ mobilizing mechanism, NO-induced Ca2+ release (NICR in cerebellar Purkinje cells. NICR is mediated by type 1 ryanodine receptor (RyR1, a Ca2+ release channel expressed in endoplasmic-reticular membrane. Furthermore, NICR is indicated to be dependent on S-nitrosylation of RyR1, and involved in synaptic plasticity in the cerebellum. In this review, molecular mechanisms and functional significance of NICR, as well as non-enzymatic posttranslational modification of proteins by gaseous signals, are described.

  5. Bilirubin prevents acute DSS-induced colitis by inhibiting leukocyte infiltration and suppressing upregulation of inducible nitric oxide synthase.

    Science.gov (United States)

    Zucker, Stephen D; Vogel, Megan E; Kindel, Tammy L; Smith, Darcey L H; Idelman, Gila; Avissar, Uri; Kakarlapudi, Ganesh; Masnovi, Michelle E

    2015-11-15

    Bilirubin is thought to exert anti-inflammatory effects by inhibiting vascular cell adhesion molecule-1 (VCAM-1)-dependent leukocyte migration and by suppressing the expression of inducible nitric oxide synthase (iNOS). As VCAM-1 and iNOS are important mediators of tissue injury in the dextran sodium sulfate (DSS) murine model of inflammatory colitis, we examined whether bilirubin prevents colonic injury in DSS-treated mice. Male C57BL/6 mice were administered 2.5% DSS in the drinking water for 7 days, while simultaneously receiving intraperitoneal injections of bilirubin (30 mg/kg) or potassium phosphate vehicle. Disease activity was monitored, peripheral blood counts and serum nitrate levels were determined, and intestinal specimens were analyzed for histological injury, leukocyte infiltration, and iNOS expression. The effect of bilirubin on IL-5 production by HSB-2 cells and on Jurkat cell transendothelial migration also was determined. DSS-treated mice that simultaneously received bilirubin lost less body weight, had lower serum nitrate levels, and exhibited reduced disease severity than vehicle-treated animals. Concordantly, histopathological analyses revealed that bilirubin-treated mice manifested significantly less colonic injury, including reduced infiltration of eosinophils, lymphocytes, and monocytes, and diminished iNOS expression. Bilirubin administration also was associated with decreased eosinophil and monocyte infiltration into the small intestine, with a corresponding increase in peripheral blood eosinophilia. Bilirubin prevented Jurkat migration but did not alter IL-5 production. In conclusion, bilirubin prevents DSS-induced colitis by inhibiting the migration of leukocytes across the vascular endothelium and by suppressing iNOS expression.

  6. Development and validation of a dynamic outcome prediction model for paracetamol-induced acute liver failure

    DEFF Research Database (Denmark)

    Bernal, William; Wang, Yanzhong; Maggs, James

    2016-01-01

    BACKGROUND: Early, accurate prediction of survival is central to management of patients with paracetamol-induced acute liver failure to identify those needing emergency liver transplantation. Current prognostic tools are confounded by recent improvements in outcome independent of emergency liver ...... in paracetamol-induced acute liver failure require re-evaluation. FUNDING: Foundation for Liver Research. Copyright © 2016 Elsevier Ltd. All rights reserved....... normalised ratio (INR), and cardiovascular failure were used to derive an initial predictive model, with a second (day 2) model including additional changes in INR and lactate. FINDINGS: We developed and validated new high-performance statistical models to support decision making in patients with paracetamol...

  7. Study of Nitric Oxide production by murine peritoneal macrophages induced by Brucella Lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Kavoosi G

    2001-07-01

    Full Text Available Brueclla is a gram negative bacteria that causes Brucellosis. Lipopolysaccharide (LPS ", the pathogenic agent of Brucella is composed of O-chain, core oligosaccharide and lipid A. in addition, the structural and biological properties of different LPS extracted from different strains are not identical. The first defense system against LPS is nonspecific immunity that causes macrophage activation. Activated macrophages produce oxygen and nitrogen radicals that enhance the protection against intracellular pathogens.In this experiment LPS was extracted by hot phenol- water procedure and the effect of various LPSs on nitric oxide prodution by peritoneal mouse macrophages was examined.Our results demonstrated that the effect of LPS on nitric oxide production is concentration-dependent we observed the maximum response in concentration of 10-20 microgram per milliliter. Also our results demonstrate that LPS extracted from vaccine Brucella abortus (S 19 had a highe effect on nitric oxide production than the LPS from other strains

  8. Influence of nitric oxide synthase inhibitor on gerbil behavior after hyperbaric oxygen-induced convulsion

    Institute of Scientific and Technical Information of China (English)

    Jianguang Zhou; Changyun Liu; Yiqun Fang; Yingqi Zhou; Erli Xu; Jingchang Liu

    2008-01-01

    BACKGROUND: Studies have reported that nitric oxide synthase (NOS) inhibitor can prolong the latency of hyperbaric oxygen-induced convulsion (HBOC). However, there are very few reports addressing the influence of NOS inhibitor on mental behavior.OBJECTIVE: To investigate behavioral changes after HBOC in gerbils, as well as the influence of NOS inhibitor.DESIGN, TIME AND SETTING: Randomized experiments were performed in the Laboratory of Hyperbaric Pressure and Diving Physiology, Naval Medical Research Institute of Chinese PLA (Shanghai,China) from March 2005 to June 2007.MATERIALS: Forty male gerbils were randomly divided into five groups: HBOC, saline control, NOS inhibitor, pressure control, and normal control. Each group contained eight animals.METHODS: In the HBOC group, once depression induction ended, animals were removed from the chamber five minutes after the first appearance of generalized convulsion induced by 0.5 MPa hyperbaric oxygen. Ten minutes before entering the chamber, saline control and NOS inhibitor animals were intraperitoneally injected with 1 mL saline and 20 mg/kg NG-nitro-L-arginine, respectively. The pressure control group was only exposed to 0.5 MPa. The remaining procedures in these three groups were identical to the HBOC group. The normal control group received no intervention.MAIN OUTCOME MEASURES: Open field test scores in gerbils prior to HBOC, as well as immediately,24 hours, and 72 hours after decompression ended.RESULTS: HBOC was not detected in either the normal control or the pressure control group, and there were no significant differences in opcn field test scores prior to and after HBOC (P > 0.05). HBOC occurred in the HBOC, saline control, and NOS inhibitor groups, with significant differences in open field test scores after decompression ended compared to normal control and pressure control groups (P < 0.05-0.01).Compared to the HBOC and saline control groups, the NOS inhibitor group exhibited a significantly lower score in

  9. Inducible nitric oxide synthase in heart tissue and nitric oxide in serum of Trypanosoma cruzi-infected rhesus monkeys: association with heart injury.

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    Cristiano Marcelo Espinola Carvalho

    Full Text Available BACKGROUND: The factors contributing to chronic Chagas' heart disease remain unknown. High nitric oxide (NO levels have been shown to be associated with cardiomyopathy severity in patients. Further, NO produced via inducible nitric oxide synthase (iNOS/NOS2 is proposed to play a role in Trypanosoma cruzi control. However, the participation of iNOS/NOS2 and NO in T. cruzi control and heart injury has been questioned. Here, using chronically infected rhesus monkeys and iNOS/NOS2-deficient (Nos2(-/- mice we explored the participation of iNOS/NOS2-derived NO in heart injury in T. cruzi infection. METHODOLOGY: Rhesus monkeys and C57BL/6 and Nos2(-/- mice were infected with the Colombian T. cruzi strain. Parasite DNA was detected by polymerase chain reaction, T. cruzi antigens and iNOS/NOS2(+ cells were immunohistochemically detected in heart sections and NO levels in serum were determined by Griess reagent. Heart injury was assessed by electrocardiogram (ECG, echocardiogram (ECHO, creatine kinase heart isoenzyme (CK-MB activity levels in serum and connexin 43 (Cx43 expression in the cardiac tissue. RESULTS: Chronically infected monkeys presented conduction abnormalities, cardiac inflammation and fibrosis, which resembled the spectrum of human chronic chagasic cardiomyopathy (CCC. Importantly, chronic myocarditis was associated with parasite persistence. Moreover, Cx43 loss and increased CK-MB activity levels were primarily correlated with iNOS/NOS2(+ cells infiltrating the cardiac tissue and NO levels in serum. Studies in Nos2(-/- mice reinforced that the iNOS/NOS2-NO pathway plays a pivotal role in T. cruzi-elicited cardiomyocyte injury and in conduction abnormalities that were associated with Cx43 loss in the cardiac tissue. CONCLUSION: T. cruzi-infected rhesus monkeys reproduce features of CCC. Moreover, our data support that in T. cruzi infection persistent parasite-triggered iNOS/NOS2 in the cardiac tissue and NO overproduction might contribute

  10. Inducible nitric oxide synthase in heart tissue and nitric oxide in serum of Trypanosoma cruzi-infected rhesus monkeys: association with heart injury.

    Directory of Open Access Journals (Sweden)

    Cristiano Marcelo Espinola Carvalho

    Full Text Available BACKGROUND: The factors contributing to chronic Chagas' heart disease remain unknown. High nitric oxide (NO levels have been shown to be associated with cardiomyopathy severity in patients. Further, NO produced via inducible nitric oxide synthase (iNOS/NOS2 is proposed to play a role in Trypanosoma cruzi control. However, the participation of iNOS/NOS2 and NO in T. cruzi control and heart injury has been questioned. Here, using chronically infected rhesus monkeys and iNOS/NOS2-deficient (Nos2(-/- mice we explored the participation of iNOS/NOS2-derived NO in heart injury in T. cruzi infection. METHODOLOGY: Rhesus monkeys and C57BL/6 and Nos2(-/- mice were infected with the Colombian T. cruzi strain. Parasite DNA was detected by polymerase chain reaction, T. cruzi antigens and iNOS/NOS2(+ cells were immunohistochemically detected in heart sections and NO levels in serum were determined by Griess reagent. Heart injury was assessed by electrocardiogram (ECG, echocardiogram (ECHO, creatine kinase heart isoenzyme (CK-MB activity levels in serum and connexin 43 (Cx43 expression in the cardiac tissue. RESULTS: Chronically infected monkeys presented conduction abnormalities, cardiac inflammation and fibrosis, which resembled the spectrum of human chronic chagasic cardiomyopathy (CCC. Importantly, chronic myocarditis was associated with parasite persistence. Moreover, Cx43 loss and increased CK-MB activity levels were primarily correlated with iNOS/NOS2(+ cells infiltrating the cardiac tissue and NO levels in serum. Studies in Nos2(-/- mice reinforced that the iNOS/NOS2-NO pathway plays a pivotal role in T. cruzi-elicited cardiomyocyte injury and in conduction abnormalities that were associated with Cx43 loss in the cardiac tissue. CONCLUSION: T. cruzi-infected rhesus monkeys reproduce features of CCC. Moreover, our data support that in T. cruzi infection persistent parasite-triggered iNOS/NOS2 in the cardiac tissue and NO overproduction might contribute

  11. Involvement of nitric oxide signaling in mammalian Bax-induced terpenoid indole alkaloid production of Catharanthus roseus cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Bax, a mammalian pro-apoptotic member of the Bcl-2 family, has been demonstrated to be a potential regulatory factor for plant secondary metabolite biosynthesis recently. To investigate the molecular mechanism of Bax-induced secondary metabolite biosynthesis, we determined the contents of nitric oxide (NO) of the transgenic Catharanthus roseus cells overexpressing a mouse Bax protein and checked the effects of NO specific scavenger 2,4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1- oxyl-3-oxide (cPITO) on Bax-induced terpenoid indole alkaloid (TIA) production of the cells. The data showed that overexpression of the mouse Bax in C. roseus cells triggered NO generation of the cells. Treatment of cPITO not only inhibited the Bax-triggered NO burst but also suppressed the Bax-induced TIA production. The results indicated that the mouse Bax might activate the NO signaling in C. roseus cells and induce TIA production through the NO-dependent signal pathway in the cells. Furthermore, the activities of nitric oxide synthase (NOS) were significantly increased in the transgenic Bax cells as compared to those in the control cells, showing that the mouse Bax may induce NOS of C. roseus cells. Treatment of the transgenic Bax cells with NOS inhibitor PBITU blocked both Bax-induced NO generation and TIA production, which suggested that the mouse Bax might trigger NO generation and TIA production through NOS. However, the NOS-like activities and NO generation in the transgenic Bax cells did not match kinetically and the Bax-induced NOS-like activity was much later and lower than NO production. Moreover, the Bax-induced NO generation and TIA production were only partially inhibited by PBITU. Thus, our results suggested that the Bax-induced NO production and secondary metabolite biosynthesis in C. roseus cells was not entirely dependent on NOS or NOS-like enzymes.

  12. 2-phenylethynesulfonamide Prevents Induction of Pro-inflammatory Factors and Attenuates LPS-induced Liver Injury by Targeting NHE1-Hsp70 Complex in Mice.

    Directory of Open Access Journals (Sweden)

    Chao Huang

    Full Text Available The endotoxin-mediated production of pro-inflammatory cytokines plays an important role in the pathogenesis of liver disorders. Heat shock protein (Hsp70 overexpression has established functions in lipopolysaccharide (LPS-mediated inflammatory response. However, little is known about the role of Hsp70 activity in LPS signaling. We hypothesized that inhibition of Hsp70 substrate binding activity can ameliorate LPS-induced liver injury by decreasing induction of pro-inflammatory factors. In this study, C57/BL6 mice were injected intraperitoneally with LPS and 2-phenylethynesulfonamide (PES, an inhibitor of Hsp70 substrate binding activity. We found that i. PES prevented LPS-induced increase in serum alanine aminotransferase (ALT and aspartate aminotransferase (AST activity, infiltration of inflammatory cells, and liver cell apoptosis; ii. PES reduced inducible nitric oxide synthase (iNOS protein expression as well as serum nitric oxide (NO, tumor necrosis factor-α (TNF-α, and interleukin-6 (IL-6 content in LPS-stimulated mice; iii. PES reduced the mRNA level of iNOS, TNF-α, and IL-6 in LPS-stimulated liver. iiii. PES attenuated the degradation of inhibitor of κB-α (IκB-α as well as the phosphorylation and nuclear translocation of nuclear factor-κB (NF-κB in LPS-stimulated liver. Similar changes in the protein expression of inflammatory markers, IκB-α degradation, and NF-κB phosphorylation and nuclear translocation were observed in RAW 264.7 cells. Further mechanistic studies revealed that PES remarkably reduced the elevation of [Ca(2+]i and intracellular pH value (pHi in LPS-stimulated RAW 264.7 cells. Furthermore, PES significantly reduced the increase in Na(+/H(+ exchanger 1 (NHE1 association to Hsp70 in LPS-stimulated macrophages and liver, suggesting that NHE1-Hsp70 interaction is required for the involvement of NHE1 in the inflammation response. In conclusion, inhibition of Hsp70 substrate binding activity in vivo reduces the

  13. Identification and Categorization of Liver Toxicity Markers Induced by a Related Pair of Drugs

    OpenAIRE

    Fuscoe, James C.; Tao Han; Chen, James J; Beland, Frederick A.; Hines, Wade M.; Ching-Wei Chang

    2011-01-01

    Drug-induced liver injury (DILI) is the primary adverse event that results in the withdrawal of drugs from the market and a frequent reason for the failure of drug candidates in the pre-clinical or clinical phases of drug development. This paper presents an approach for identifying potential liver toxicity genomic biomarkers from a liver toxicity biomarker study involving the paired compounds entacapone (“non-liver toxic drug”) and tolcapone (“hepatotoxic drug”). Molecular analysis of the rat...

  14. Inhibition of IFN-γ-Induced Nitric Oxide Dependent Antimycobacterial Activity by miR-155 and C/EBPβ

    Directory of Open Access Journals (Sweden)

    Yongwei Qin

    2016-04-01

    Full Text Available miR-155 (microRNA-155 is an important non-coding RNA in regulating host crucial biological regulators. However, its regulatory function in mycobacterium infection remains unclear. Our study demonstrates that miR-155 expression is significantly increased in macrophages after Mycobacterium marinum (M.m infection. Transfection with anti-miR-155 enhances nitric oxide (NO synthesis and decreases the mycobacterium burden, and vice versa, in interferon γ (IFN-γ activated macrophages. More importantly, miR-155 can directly bind to the 3′UTR of CCAAT/enhancer binding protein β (C/EBPβ, a positive transcriptional regulator of nitric oxide synthase (NOS2, and regulate C/EBPβ expression negatively. Knockdown of C/EBPβ inhibit the production of nitric oxide synthase and promoted mycobacterium survival. Collectively, these data suggest that M.m-induced upregulation of miR-155 downregulated the expression of C/EBPβ, thus decreasing the production of NO and promoting mycobacterium survival, which may provide an insight into the function of miRNA in subverting the host innate immune response by using mycobacterium for its own profit. Understanding how miRNAs partly regulate microbicidal mechanisms may represent an attractive way to control tuberculosis infectious.

  15. Proteomic profiling in incubation medium of mouse, rat and human precision-cut liver slices for biomarker detection regarding acute drug-induced liver injury

    NARCIS (Netherlands)

    van Swelm, Rachel P. L.; Hadi, Mackenzie; Laarakkers, Coby M. M.; Masereeuw, Rosalinde; Groothuis, Geny M. M.; Russel, Frans G. M.

    2014-01-01

    Drug-induced liver injury is one of the leading causes of drug withdrawal from the market. In this study, we investigated the applicability of protein profiling of the incubation medium of human, mouse and rat precision-cut liver slices (PCLS) exposed to liver injury-inducing drugs for biomarker ide

  16. Antihypertensive effect of gomisin A from Schisandra chinensis on angiotensin II-induced hypertension via preservation of nitric oxide bioavailability.

    Science.gov (United States)

    Young Park, Ji; Wook Yun, Jung; Whan Choi, Young; Ung Bae, Jin; Won Seo, Kyo; Jin Lee, Seung; Youn Park, So; Whan Hong, Ki; Kim, Chi Dae

    2012-09-01

    Gomisin A (GA) is a small molecular weight lignan present in Schisandra chinensis, and has been demonstrated to have vasodilatory activity. In the present study, we investigated the effect of GA on blood pressure (BP) in angiotensin II (Ang II)-induced hypertensive mice. C57/BL6 mice infused subcutaneously with Ang II (1 and 2 μg kg⁻¹ per min for 2 weeks) showed an increase in BP with a decrease in nitric oxide (NO) metabolites in plasma, and a negative correlation between these two parameters was demonstrated. In the thoracic aorta from Ang II-induced hypertensive mice, a decrease in vascular NO that was accompanied by a diminution of phosphorylated endothelial nitric oxide synthase (eNOS), as well as by increased reactive oxygen species (ROS) production, was demonstrated. These alterations in BP, eNOS phosphorylation and ROS production in the vasculature of Ang II-treated mice were markedly and dose-dependently reversed by simultaneous administration of GA (2 and 10 μg kg⁻¹ per min). In addition, Ang II-induced ROS production in cultured vascular cells such as endothelial cells and vascular smooth muscle cells was markedly attenuated by GA. These results suggested that GA attenuated the increase in BP via preservation of vascular NO bioavailability not only by inhibiting ROS production but also by preventing the impairment of eNOS function in the vasculature of Ang II-induced hypertensive mice.

  17. H2O2-induced Leaf Cell Death and the Crosstalk of Reactive Nitric/Oxygen Species([F])

    Institute of Scientific and Technical Information of China (English)

    Yiqin Wang; Aihong Lin; Gary J.Loake; Chengcai Chu

    2013-01-01

    In plants,the chloroplast is the main reactive oxygen species (ROS) producing site under high light stress.Catalase (CAT),which decomposes hydrogen peroxide (H2O2),is one of the controlling enzymes that maintains leaf redox homeostasis.The catalase mutants with reduced leaf catalase activity from different plant species exhibit an H2O2-induced leaf cell death phenotype.This phenotype was differently affected by light intensity or photoperiod,which may be caused by plant species,leaf redox status or growth conditions.In the rice CAT mutant nitric oxide excess 1 (noe1),higher H2O2 levels induced the generation of nitric oxide (NO) and higher S-nitrosothiol (SNO) levels,suggesting that NO acts as an important endogenous mediator in H2O2-induced leaf cell death.As a free radical,NO could also react with other intracellular and extracellular targets and form a series of related molecules,collectively called reactive nitrogen species (RNS).Recent studies have revealed that both RNS and ROS are important partners in plant leaf cell death.Here,we summarize the recent progress on H2O2-induced leaf cell death and the crosstalk of RNS and ROS signals in the plant hypersensitive response (HR),leaf senescence,and other forms of leaf cell death triggered by diverse environmental conditions.

  18. The role of nitric oxide and oxidative stress in intestinal damage induced by selenium deficiency in chickens.

    Science.gov (United States)

    Yu, Jiao; Yao, Haidong; Gao, Xuejiao; Zhang, Ziwei; Wang, Jiu-Feng; Xu, Shi-Wen

    2015-02-01

    Nitric oxide (NO) is an essential messenger molecule and is associated with inflammation and oxidative stress. Although NO has important biological functions in mammals, its role in the mechanism that occurs after intestinal injuries in chickens remains unknown. The objective of the present study was to investigate the real role of NO and oxidative stress in the intestinal injuries of chickens induced by selenium (Se) deficiency. A total 150 chickens were randomly divided into the following two groups: a low-Se group (L group, fed a Se-deficient diet containing 0.020 mg/kg Se) and a control group (C group, fed a commercial diet containing 0.2 mg/kg Se). The activities and mRNA levels of glutathione peroxidase (GSH-Px), the production of glutathione (GSH) and NO, and the protein and mRNA levels of inducible nitric oxide synthase (iNOS) were examined in the intestinal tissues (duodenum, jejunum, and rectum) at 15, 25, 35, 45, and 55 days. Methane dicarboxylic aldehyde (MDA) levels were also detected by assay kits. Then, the morphologies of the tissues were observed under the microscope after hematoxylin and eosin staining (H&E staining). The results showed that Se deficiency induced higher inflammatory damage and MDA levels (P chickens and that low levels of GSH-Px and high contents of NO may exert a major role in the injury of the intestinal tract induced by Se deficiency.

  19. Drug-induced liver injury and drug development: industry perspective.

    Science.gov (United States)

    Regev, Arie

    2014-05-01

    Despite intensive ongoing research, drug-induced live injury (DILI) remains a serious issue for care providers and patients, and has been a major cause of drug withdrawal and non-approval by regulatory authorities in the past 50 years. Consequently, DILI remains a major concern for the pharmaceutical industry and a leading cause for attrition during drug development. In most instances, severe DILI is an uncommon idiosyncratic reaction, which typically does not present during preclinical phases or early clinical phases of drug development. In the majority of cases, drugs that caused severe DILI in humans have not shown clear and consistent hepatotoxic signals in preclinical assessment including animal studies, cell cultures, or other methods. Despite intensive efforts to develop better biomarkers that would help in predicting DILI risk in earlier phases of drug development, such biomarkers are currently not supported by sufficient evidence and are not yet available for routine use by drug makers. Due to the lack of effective and accurate methods for prediction of idiosyncratic DILI during preclinical phases of drug development, different drug makers have adopted different approaches, which are often not supported by strong systematic evidence. Based on growing experience, it is becoming increasingly evident that milder forms of liver injury occurring during clinical development, when assessed correctly, may significantly enhance our ability to predict the drug's potential to cause more severe liver injury postmarketing. Strategies based on this concept have been adopted by many drug makers, and are being increasingly implemented during drug development. Meticulous causality assessment of individual hepatic cases and adherence to strict hepatic discontinuation rules are critical components of this approach and have to rely on thorough clinical evaluation and occasionally on assessment by liver experts experienced with DILI and drug development.

  20. Nitric oxide and chronic colitis

    Directory of Open Access Journals (Sweden)

    Matthew B Grisham

    1996-01-01

    Full Text Available Nitric oxide (NO is thought to play an important role in modulating the inflammatory response by virtue of its ability to affect bloodflow, leukocyte function and cell viability. The objective of this study was to assess the role that NO may play in mediating the mucosal injury and inflammation in a model of chronic granulomatous colitis using two pharmacologically different inhibitors of nitric oxide synthase (NOS. Chronic granulomatous colitis with liver and spleen inflammation was induced in female Lewis rats via the subserosal (intramural injection of peptidoglycan/polysaccharide (PG/PS derived from group A streptococci. Chronic NOS inhibition by oral administration of NG-nitro-L-arginine methyl ester (L-NAME (15 µmol/kg/day or amino-guanidine (AG (15 µmol/ kg/day was found to attenuate the PG/PS-induced increases in macroscopic colonic inflammation scores and colonic myeloperoxidase activity. Only AG -- not L-NAME – attenuated the PG/PS-induced increases in colon dry weight. Both L-NAME and AG significantly attenuated the PG/PS-induced increases in spleen weight whereas neither was effective at significantly attenuating the PG/PS-induced increases in liver weight. Although both L-NAME and AG inhibited NO production in vivo, as measured by decreases in plasma nitrite and nitrate levels, only AG produced significantly lower values (38±3 versus 83±8 µM, respectively, P<0.05. Finally, L-NAME, but not AG, administration significantly increased mean arterial pressure from 83 mmHg in colitic animals to 105 mmHg in the PG/PS+ L-NAME-treated animals (P<0.05. It is concluded that NO may play an important role in mediating some of the pathophysiology associated with this model of chronic granulomatous colitis.

  1. Acute restraint stress induces specific changes in nitric oxide production and inflammatory markers in the rat hippocampus and striatum.

    Science.gov (United States)

    Chen, Hsiao-Jou Cortina; Spiers, Jereme G; Sernia, Conrad; Lavidis, Nickolas A

    2016-01-01

    Chronic mild stress has been shown to cause hippocampal neuronal nitric oxide synthase (NOS) overexpression and the resultant nitric oxide (NO) production has been implicated in the etiology of depression. However, the extent of nitrosative changes including NOS enzymatic activity and the overall output of NO production in regions of the brain like the hippocampus and striatum following acute stress has not been characterized. In this study, outbred male Wistar rats aged 6-7 weeks were randomly allocated into 0 (control), 60, 120, or 240 min stress groups and neural regions were cryodissected for measurement of constitutive and inducible NOS enzymatic activity, nitrosative status, and relative gene expression of neuronal and inducible NOS. Hippocampal constitutive NOS activity increased initially but was superseded by the inducible isoform as stress duration was prolonged. Interestingly, hippocampal neuronal NOS and interleukin-1β mRNA expression was downregulated, while the inducible NOS isoform was upregulated in conjunction with other inflammatory markers. This pro-inflammatory phenotype within the hippocampus was further confirmed with an increase in the glucocorticoid-antagonizing macrophage migration inhibitory factor, Mif, and the glial surveillance marker, Ciita. This indicates that despite high levels of glucocorticoids, acute stress sensitizes a neuroinflammatory response within the hippocampus involving both pro-inflammatory cytokines and inducible NOS while concurrently modulating the immunophenotype of glia. Furthermore, there was a delayed increase in striatal inducible NOS expression while no change was found in other pro-inflammatory mediators. This suggests that short term stress induces a generalized increase in inducible NOS signaling that coincides with regionally specific increased markers of adaptive immunity and inflammation within the brain.

  2. Hepatoprotective Effects of Vitamin E Against Malathion-Induced Mitochondrial Dysfunction in Rat Liver

    Directory of Open Access Journals (Sweden)

    Ranjbar

    2014-09-01

    Full Text Available Background Malathion is an insecticide of the grouping of organophosphate pesticides (OPs, which shows strong insecticidal effects. In addition, vitamin E reacting to cell membrane site may prevent OP-induced oxidative injury. Objectives The aim of this study was to examine the protective function of vitamin E on toxicity of malathion, by measuring the activities of liver and liver mitochondrial superoxide dismutase (SOD, catalase (CAT,lipid peroxidation (LPO,and glutathione peroxidase (GPx in rats. Materials and Methods The mitochondrial viability was determined in liver. ‎Effective doses of malathion(200 mg/kg/day and vitamin E (alpha-tocopherylacetate [AT]; 15 mg/kg/day were administered alone or in combination for 14 days. At the end of the experiment, the liver tissue and liver mitochondria of the animals were harvested and examined. Results In liver tissue, the activity of LPO and CAT was higher in the malathion group in comparison to controls. AT reduced malathion-induced LPO, SOD, CAT, and GPx in rat liver. Coadministration of AT with malathion improved LPO, SOD, and CAT levels in liver as well as CAT and GPx in liver mitochondria. Malathion-induced mitochondria toxicity was recovered by AT. Conclusions In conclusion, AT measurement can be beneficial for the safety or recovery of malathion-induced toxic injury in liver tissue and liver mitochondria.

  3. Radiation-Induced Liver Damage: Correlation of Histopathology with Hepatobiliary Magnetic Resonance Imaging, a Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Seidensticker, Max, E-mail: max.seidensticker@med.ovgu.de [Universitätsklinik Magdeburg, Klinik für Radiologie und Nuklearmedizin (Germany); Burak, Miroslaw [Pomeranian Medical University, Department of Diagnostic Imaging and Interventional Radiology (Poland); Kalinski, Thomas [Universitätsklinik Magdeburg, Institut für Pathologie (Germany); Garlipp, Benjamin [Universitätsklinik Magdeburg, Klinik für Allgemein-, Viszeral- und Gefäßchirurgie (Germany); Koelble, Konrad [Philipps Universität Marburg, Fachbereich Medizin der, Abteilung für Neuropathologie (Germany); Wust, Peter [Charité Universitätsmedizin Berlin, Klinik für Radioonkologie und Strahlentherapie (Germany); Antweiler, Kai [Universitätsklinik Magdeburg, Institut für Biometrie und Medizinische Informatik (Germany); Seidensticker, Ricarda; Mohnike, Konrad; Pech, Maciej; Ricke, Jens [Universitätsklinik Magdeburg, Klinik für Radiologie und Nuklearmedizin (Germany)

    2015-02-15

    PurposeRadiotherapy of liver malignancies shows promising results (radioembolization, stereotactic irradiation, interstitial brachytherapy). Regardless of the route of application, a certain amount of nontumorous liver parenchyma will be collaterally damaged by radiation. The functional reserve may be significantly reduced with an impact on further treatment planning. Monitoring of radiation-induced liver damage by imaging is neither established nor validated. We performed an analysis to correlate the histopathological presence of radiation-induced liver damage with functional magnetic resonance imaging (MRI) utilizing hepatobiliary contrast media (Gd-BOPTA).MethodsPatients undergoing local high-dose-rate brachytherapy for whom a follow-up hepatobiliary MRI within 120 days after radiotherapy as well as an evaluable liver biopsy from radiation-exposed liver tissue within 7 days before MRI were retrospectively identified. Planning computed tomography (CT)/dosimetry was merged to the CT-documentation of the liver biopsy and to the MRI. Presence/absence of radiation-induced liver damage (histopathology) and Gd-BOPTA uptake (MRI) as well as the dose applied during brachytherapy at the site of tissue sampling was determined.ResultsFourteen biopsies from eight patients were evaluated. In all cases with histopathological evidence of radiation-induced liver damage (n = 11), no uptake of Gd-BOPTA was seen. In the remaining three, cases no radiation-induced liver damage but Gd-BOPTA uptake was seen. Presence of radiation-induced liver damage and absence of Gd-BOPTA uptake was correlated with a former high-dose exposition.ConclusionsAbsence of hepatobiliary MRI contrast media uptake in radiation-exposed liver parenchyma may indicate radiation-induced liver damage. Confirmatory studies are warranted.

  4. Acetaminophen-induced acute liver injury in mice.

    Science.gov (United States)

    Mossanen, J C; Tacke, F

    2015-04-01

    The induction of acute hepatic damage by acetaminophen (N-acetyl-p-aminophenol [APAP]), also termed paracetamol, is one of the most commonly used experimental models of acute liver injury in mice. The specific values of this model are the highly reproducible, dose-dependent hepatotoxicity of APAP and its outstanding translational importance, because acetaminophen overdose is one of the most frequent reasons for acute liver failure (ALF) in humans. However, preparation of concentrated APAP working solutions, application routes, fasting period and variability due to sex, genetic background or barrier environment represent important considerations to be taken into account before implementing this model. This standard operating procedure (SOP) provides a detailed protocol for APAP preparation and application in mice, aimed at facilitating comparability between research groups as well as minimizing animal numbers and distress. The mouse model of acetaminophen poisoning therefore helps to unravel the pathogenesis of APAP-induced toxicity or subsequent immune responses in order to explore new therapeutic interventions for improving the prognosis of ALF in patients.

  5. The Molecular Circadian Clock and Alcohol-Induced Liver Injury.

    Science.gov (United States)

    Udoh, Uduak S; Valcin, Jennifer A; Gamble, Karen L; Bailey, Shannon M

    2015-10-14

    Emerging evidence from both experimental animal studies and clinical human investigations demonstrates strong connections among circadian processes, alcohol use, and alcohol-induced tissue injury. Components of the circadian clock have been shown to influence the pathophysiological effects of alcohol. Conversely, alcohol may alter the expression of circadian clock genes and the rhythmic behavioral and metabolic processes they regulate. Therefore, we propose that alcohol-mediated disruption in circadian rhythms likely underpins many adverse health effects of alcohol that cut across multiple organ systems. In this review, we provide an overview of the circadian clock mechanism and showcase results from new studies in the alcohol field implicating the circadian clock as a key target of alcohol action and toxicity in the liver. We discuss various molecular events through which alcohol may work to negatively impact circadian clock-mediated processes in the liver, and contribute to tissue pathology. Illuminating the mechanistic connections between the circadian clock and alcohol will be critical to the development of new preventative and pharmacological treatments for alcohol use disorders and alcohol-mediated organ diseases.

  6. The Molecular Circadian Clock and Alcohol-Induced Liver Injury

    Directory of Open Access Journals (Sweden)

    Uduak S. Udoh

    2015-10-01

    Full Text Available Emerging evidence from both experimental animal studies and clinical human investigations demonstrates strong connections among circadian processes, alcohol use, and alcohol-induced tissue injury. Components of the circadian clock have been shown to influence the pathophysiological effects of alcohol. Conversely, alcohol may alter the expression of circadian clock genes and the rhythmic behavioral and metabolic processes they regulate. Therefore, we propose that alcohol-mediated disruption in circadian rhythms likely underpins many adverse health effects of alcohol that cut across multiple organ systems. In this review, we provide an overview of the circadian clock mechanism and showcase results from new studies in the alcohol field implicating the circadian clock as a key target of alcohol action and toxicity in the liver. We discuss various molecular events through which alcohol may work to negatively impact circadian clock-mediated processes in the liver, and contribute to tissue pathology. Illuminating the mechanistic connections between the circadian clock and alcohol will be critical to the development of new preventative and pharmacological treatments for alcohol use disorders and alcohol-mediated organ diseases.

  7. Low-dose ATRA Supplementation Abolishes PRM Formation in Rat Liver and Ameliorates Ethanol-induced Liver Injury

    Institute of Scientific and Technical Information of China (English)

    PAN Zhihong; DAN Zili; FU Yu; TANG Wangxian; LIN Jusheng

    2006-01-01

    The effects of all-trans-retinoic acid (ATRA) in low doses supplementation on concentrations of polar retinoid metabolites (PRM) and retinoids in the ethanol-fed rat liver, and on hepatocyte injury were investigated. The rat model of alcoholic liver disease (ALD) was induced by intragastric infusion of ethanol, and then the rats were administrated with ATRA in two different doses (150 μg/kg body weight and 1.5 mg/kg body weight) for 4 weeks. Concentrations of retinoids in rat liver and plasma were determined by using HPLC. Liver tissues pathologic changes were observed under the light microscopy and electron microscopy. The serum transaminases concentrations were measured. The results showed that the HPLC analysis of retinoids revealed that retinoids (vitamin A,RA, retinyl palmitate) concentrations in ethanol-fed rat liver and RA concentration in ethanol-fed rat plasma were markedly diminished (P<0.01) after ethanol feeding for 12 weeks. Furthermore, obvious peaks of PRM were formed in livers of ethanol-fed rats. ATRA 150 μg/kg supplementation in ethanol-fed rats for 4 weeks raised RA concentration in both liver and plasma, and also raised vitamin A concentration in liver to control levels, partially restored retinyl palmitate concentration (P<0.05) in liver. ATRA 1.5 mg/kg supplementation raised not only RA concentrations in liver and plasma but also retinyl palmitate concentrations in liver. However, the vitamin A concentration in liver of ATRA-supplemented rats (1.5 mg/kg) was higher than that of controls (P<0.05). The histologic observation of liver tissues indicated that ATRA treatment notably alleviated hepatocellular swelling,steatosis, the swelling of mitochondria and proliferation of smooth endoplasmic reticulum (SER).ATRA treatment greatly decreased levels of serum transaminases as compared with the only ethanol-fed group (P<0.05). It was concluded that low-dose ATRA treatment could restore retinoids concentrations and abolish the PRM formation

  8. Exhaled nitric oxide predicts exercise-induced bronchoconstriction in asthmatic school children

    DEFF Research Database (Denmark)

    Buchvald, Frederik; Hermansen, Mette N; Nielsen, Kim G;

    2005-01-01

    used in routine monitoring of pediatric asthma control. The fractional concentration of exhaled nitric oxide (FeNO) also reflects uncontrolled asthma. We hypothesized that FeNO may be used for prescreening of asthmatic children to exclude those with good asthma control unlikely to have EIB, thereby...

  9. Inducible nitric oxide synthase expression is upregulated in oral submucous fibrosis

    Directory of Open Access Journals (Sweden)

    Rajendran R

    2007-01-01

    Full Text Available Objective: We tested the hypothesis that inducible nitric oxide synthase (iNOS modulates angiogenesis in human models and this information could be extrapolated in elucidating the pathophysiology of oral submucous fibrosis (OSF. A hypothesis which looks inadequate, but is deep rooted in literature is the epithelial alteration ("atrophy" seen in OSF and the events that lead to its causation. This aspect was tried to be addressed and an alternative pathogenetic pathway for the disease is proposed. Materials and Methods: This immunohistochemical study sought to investigate the expression of iNOS in OSF samples (n= 30 a using monospecific antibody (SC- 2050, Santa Cruz Biotechnology, Inc to the protein and also to correlate it with different grades of epithelial dysplasia associated with the disease. Twenty (20 healthy adults acted as controls. Results: iNOS staining was not demonstrated in normal oral epithelium. In oral epithelial dysplasia, staining was seen in all cases (100% in the basal layers of the epithelium and in 30% of cases it extended into the parabasal compartments as well. iNOS staining was uniformly positive in moderate dysplasia with an increase in intensity and distribution noted as the severity of dysplasia progressed. There were highly significant differences in overall positivity for iNOS in epithelium between cases and controls (Mann-Whitney U = 11.000, Wilcoxon W = 221.00, P = 0.000. Significant comparisons were made of mild Vs moderate dysplasia (Mann-Whitney U = 48.000, P = 0.014 Conclusions: This study supports our earlier morphological assessment (image analysis of the nature of vascularity in OSF mucosa. The significant vasodilation noticed in these cases argues against the concept of ischemic atrophy of the epithelium. This observation of vascularity and iNOS expression helped to explain the vasodilation noticed (sinusoids in this disease; NO being a net vasodilator. The mechanism of activation of iNOS in dysplasia is

  10. Altered Nitric Oxide Bioavailability Contributes to Diesel Exhaust Inhalation‐Induced Cardiovascular Dysfunction in Man

    Science.gov (United States)

    Langrish, Jeremy P.; Unosson, Jon; Bosson, Jenny; Barath, Stefan; Muala, Ala; Blackwell, Scott; Söderberg, Stefan; Pourazar, Jamshid; Megson, Ian L.; Treweeke, Andrew; Sandström, Thomas; Newby, David E.; Blomberg, Anders; Mills, Nicholas L.

    2013-01-01

    Background Diesel exhaust inhalation causes cardiovascular dysfunction including impaired vascular reactivity, increased blood pressure, and arterial stiffness. We investigated the role of nitric oxide (NO) bioavailability in mediating these effects. Methods and Results In 2 randomized double‐blind crossover studies, healthy nonsmokers were exposed to diesel exhaust or filtered air. Study 1: Bilateral forearm blood flow was measured during intrabrachial infusions of acetylcholine (ACh; 5 to 20 μg/min) and sodium nitroprusside (SNP; 2 to 8 μg/min) in the presence of the NO clamp (NO synthase inhibitor NG‐monomethyl‐l‐arginine (l‐NMMA) 8 μg/min coinfused with the NO donor SNP at 90 to 540 ng/min to restore basal blood flow). Study 2: Blood pressure, arterial stiffness, and cardiac output were measured during systemic NO synthase inhibition with intravenous l‐NMMA (3 mg/kg). Following diesel exhaust inhalation, plasma nitrite concentrations were increased (68±48 versus 41±32 nmol/L; P=0.006) despite similar l‐NMMA–induced reductions in basal blood flow (−20.6±14.7% versus −21.1±14.6%; P=0.559) compared to air. In the presence of the NO clamp, ACh and SNP caused dose‐dependent vasodilatation that was not affected by diesel exhaust inhalation (P>0.05 for both). Following exposure to diesel exhaust, l‐NMMA caused a greater increase in blood pressure (P=0.048) and central arterial stiffness (P=0.007), but reductions in cardiac output and increases in systemic vascular resistance (P>0.05 for both) were similar to those seen with filtered air. Conclusions Diesel exhaust inhalation disturbs normal vascular homeostasis with enhanced NO generation unable to compensate for excess consumption. We suggest the adverse cardiovascular effects of air pollution are, in part, mediated through reduced NO bioavailability. Clinical Trial Registration URL: http://www.ClinicalTrials.gov. Unique identifiers: NCT00845767 and NCT01060930. PMID:23525434

  11. Beneficial Effects of Nitric Oxide Induced Mild Oxidative Stress on Post-Thawed Bull Semen Quality

    Directory of Open Access Journals (Sweden)

    Mohsen Sharafi

    2015-07-01

    Full Text Available Background: Cryopreservation of semen requires optimized conditions to minimize the harmful effects of various stresses. The main approach for protection of sperm against stress is based on the use of antioxidants and cryoprotectants, which are described as defensive methods. Recently, the application of controlled mild stressors has been described for activation of a temporary response in oocyte, embryo and somatic cells. In this study a sub-lethal oxidative stress induced by precise concentrations of nitric oxide (NO has been evaluated for sperm during cryopreservation. Materials and Methods: In this experimental study, we used different concentrations of NO [0 μM (NO-0, 0.01 μM (NO-0.01, 0.1 μM (NO-0.1, 1 μM (NO-1, 10 μM (NO-10 and 100 μM (NO-100] during cryopreservation of bull semen. Their effects on post-thawed sperm quality that included motility and velocity parameters, plasma membrane functionality, acrosome integrity, apoptosis status, mitochondrial activity and lipid peroxidation after freezing-thawing were investigated. Results: Exposure of sperm before freezing to NO-1 significantly increased total motility (88.4 ± 2.8%, progressive motility (50.4 ± 3.2% and average path velocity (VAP, 53.8 ± 3.1 μm/s compared to other extenders. In addition, NO-1 significantly increased plasma membrane functionality (89.3 ± 2.9% compared to NO-0 (75.3 ± 2.9%, NO-0.01 (78.3 ± 2.9%, NO-0.1 (76.4 ± 2.9%, NO-10 (64 ± 2.9% and NO-100 (42 ± 2.9%. Sperm exposed to NO-1 produced the highest percentage of viable (85.6 ± 2.3% and the lowest percentage of apoptotic (10.8 ± 2.4% spermatozoa compared to the other extenders. Also, NO-100 resulted in a higher percentage of dead spermatozoa (27.1 ± 2.7% compared to the other extenders. In terms of mitochondrial activity, there was no significant difference among NO-0 (53.4 ± 3.2, NO-0.01 (52.1 ± 3.2, NO-0.1 (50.8 ± 3.2 and NO-1 (53.1 ± 3.2. For acrosome integrity, no significant different

  12. Ultraviolet-B-induced flavonoid accumulation in Betula pendula leaves is dependent upon nitrate reductase-mediated nitric oxide signaling.

    Science.gov (United States)

    Zhang, Ming; Dong, Ju-Fang; Jin, Hai-Hong; Sun, Li-Na; Xu, Mao-Jun

    2011-08-01

    Nitric oxide (NO) is an important signaling molecule involved in many physiological processes in plants. Nitric oxide generation and flavonoid accumulation are two early reactions of plants to ultraviolet-B (UV-B) irradiation. However, the source of UV-B-triggered NO generation and the role of NO in UV-B-induced flavonoid accumulation are not fully understood. In order to evaluate the origin of UV-B-triggered NO generation, we examined the responses of nitrate reductase (NR) activity and the expression levels of NIA1 and NIA2 genes in leaves of Betula pendula Roth (silver birch) seedlings to UV-B irradiation. The data show that UV-B irradiation stimulates NR activity and induces up-regulation of NIA1 but does not affect NIA2 expression during UV-B-triggered NO generation. Pretreatment of the leaves with NR inhibitors tungstate (TUN) and glutamine (Gln) abolishes not only UV-B-triggered NR activities but also UV-B-induced NO generation. Furthermore, application of TUN and Gln suppresses UV-B-induced flavonoid production in the leaves and the suppression of NR inhibitors on UV-B-induced flavonoid production can be reversed by NO via its donor sodium nitroprusside. Together, the data indicate that NIA1 in the leaves of silver birch seedlings is sensitive to UV-B and the UV-B-induced up-regulation of NIA1 may lead to enhancement of NR activity. Furthermore, our results demonstrate that NR is involved in UV-B-triggered NO generation and NR-mediated NO generation is essential for UV-B-induced flavonoid accumulation in silver birch leaves.

  13. Interaction between nitric oxide synthase and cyclooxygenase in the development of acetaminophen-induced hepatotoxicity

    Directory of Open Access Journals (Sweden)

    Meltem Kolgazi

    2015-03-01

    Results: AG and KET prevented the increase in liver malondialdehyde levels due to APAP toxicity. Decreased liver glutathione in APAP group was prevented by all treatments except NIM. Stimulated liver myeloperoxidase activity in APAP group was attenuated by all treatments except INDO and NIM. Elevation of liver chemiluminescence, nuclear factor (NF- and #61547;B expression and serum alanine transferase level due to APAP overdose were also suppressed by all treatments. Conclusions: NOS and COX pathways interact in the development of hepatotoxicity due to APAP overdose. [J Exp Integr Med 2015; 5(1.000: 16-22

  14. Temozolomide-induced liver damage. A case report

    Energy Technology Data Exchange (ETDEWEB)

    Becker, F.; Hecht, M.; Schmidtner, J.; Semrau, S.; Fietkau, R. [University of Erlangen-Nuremberg, Department of Radiation Oncology, Erlangen (Germany)

    2014-04-15

    Temozolomide (TMZ) is an alkylating agent used in chemoradiotherapy and adjuvant chemotherapy regimens for treatment of newly diagnosed or recurrent glioblastoma. In Germany alone, 900,000 daily doses of the drug are prescribed each year. Therefore, all severe side effects of TMZ, even those rarely observed, are relevant to radiotherapists. We report a case of severe drug-induced toxic hepatitis that developed during chemoradiotherapy with TMZ in a patient with glioblastoma multiforme. Transaminase elevation was observed after 5 weeks of TMZ treatment, followed by severe jaundice symptoms which only subsided 2 months later. These findings were consistent with diagnosis of the mixed hepatic/cholestatic type of drug-induced toxic hepatitis. Due to the early termination of treatment, no life-threatening complications occurred in our patient. However, rare reports of encephalopathy and fatality as complications of TMZ therapy can be found in the literature. When using TMZ for treatment of glioblastoma, monitoring of liver enzyme levels should be performed twice weekly to prevent fatal toxic hepatitis. In the case of any drug-induced hepatitis, TMZ must be discontinued immediately. (orig.)

  15. Ghrelin counteracts salt-induced hypertension via promoting diuresis and renal nitric oxide production in Dahl rats.

    Science.gov (United States)

    Aoki, Hirotaka; Nakata, Masanori; Dezaki, Katsuya; Lu, Ming; Gantulga, Darambazar; Yamamoto, Keiji; Shimada, Kazuyuki; Kario, Kazuomi; Yada, Toshihiko

    2013-01-01

    Ghrelin is the endogenous ligand for the growth hormone-secretagogue receptor expressed in various tissues including the heart, blood vessels and kidney. This study sought to determine the effects of long-term treatment with ghrelin (10 nmol/kg, twice a day, intraperitoneally) on the hypertension induced by high salt (8.0% NaCl) diet in Dahl salt-sensitive hypertensive (DS) rats. Systolic blood pressure (SBP) was measured by a tail cuff method. During the treatment period for 3 weeks, high salt diet increased blood pressure compared to normal salt (0.3% NaCl) diet, and this hypertension was partly but significantly (P<0.01) attenuated by simultaneous treatment with ghrelin. Ghrelin significantly increased urine volume and tended to increase urine Na⁺ excretion. Furthermore, ghrelin increased urine nitric oxide (NO) excretion and tended to increase renal neuronal nitric oxide synthase (nNOS) mRNA expression. Ghrelin did not alter the plasma angiotensin II level and renin activity, nor urine catecholamine levels. Furthermore, ghrelin prevented the high salt-induced increases in heart thickness and plasma ANP mRNA expression. These results demonstrate that long-term ghrelin treatment counteracts salt-induced hypertension in DS rats primarily through diuretic action associated with increased renal NO production, thereby exerting cardio-protective effects.

  16. Nitric oxide induced by polyamines involves antioxidant systems against chilling stress in tomato (Lycopersicon esculentum Mill.) seedling*#

    Science.gov (United States)

    Diao, Qian-Nan; Song, Yong-Jun; Shi, Dong-Mei; Qi, Hong-Yan

    2016-01-01

    Polyamines (PAs) and nitric oxide (NO) are vital signals in modulating plant response to abiotic stress. However, to our knowledge, studies on the relationship between NO and PAs in response to cold stress in tomato are limited. Accordingly, in this study, we investigated the effects of putrescine (Put) and spermidine (Spd) on NO generation and the function of Spd-induced NO in the tolerance of tomato seedling under chilling stress. Spd increased NO release via the nitric oxide synthase (NOS)-like and nitrate reductase (NR) enzymatic pathways in the seedlings, whereas Put had no such effect. Moreover, H2O2 might act as an upstream signal to stimulate NO production. Both exogenous NO donor (sodium nitroprusside (SNP)) and Spd enhanced chilling tolerance in tomato, thereby protecting the photosynthetic system from damage. Compared to chilling treatment alone, Spd enhanced the gene expressions of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and their enzyme activities in tomato leaves. However, a scavenger or inhibitor of NO abolished Spd-induced chilling tolerance and blocked the increased expression and activity due to Spd of these antioxidant enzymes in tomato leaves under chilling stress. The results showed that NO induced by Spd plays a crucial role in tomato’s response to chilling stress. PMID:27921397

  17. Nitric Oxide Functions as a Signal in Ultraviolet-B-Induced Baicalin Accumulation in Scutellaria baicalensis Suspension Cultures

    Directory of Open Access Journals (Sweden)

    Jin-Jie Zhang

    2014-03-01

    Full Text Available Stress induced by ultraviolet-B (UV-B irradiation stimulates the accumulation of various secondary metabolites in plants. Nitric oxide (NO serves as an important secondary messenger in UV-B stress-induced signal transduction pathways. NO can be synthesized in plants by either enzymatic catalysis or an inorganic nitrogen pathway. The effects of UV-B irradiation on the production of baicalin and the associated molecular pathways in plant cells are poorly understood. In this study, nitric oxide synthase (NOS activity, NO release and the generation of baicalin were investigated in cell suspension cultures of Scutellaria baicalensis exposed to UV-B irradiation. UV-B irradiation significantly increased NOS activity, NO release and baicalin biosynthesis in S. baicalensis cells. Additionally, exogenous NO supplied by the NO donor, sodium nitroprusside (SNP, led to a similar increase in the baicalin content as the UV-B treatment. The NOS inhibitor, Nω-nitro-l-arginine (LNNA, and NO scavenger, 2-(4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO partially inhibited UV-B-induced NO release and baicalin accumulation. These results suggest that NO is generated by NOS or NOS-like enzymes and plays an important role in baicalin biosynthesis as part of the defense response of S. baicalensis cells to UV-B irradiation.

  18. Nitric oxide induced by polyamines involves antioxidant systems against chilling stress in tomato (Lycopersicon esculentum Mill.) seedling.

    Science.gov (United States)

    Diao, Qian-Nan; Song, Yong-Jun; Shi, Dong-Mei; Qi, Hong-Yan

    Polyamines (PAs) and nitric oxide (NO) are vital signals in modulating plant response to abiotic stress. However, to our knowledge, studies on the relationship between NO and PAs in response to cold stress in tomato are limited. Accordingly, in this study, we investigated the effects of putrescine (Put) and spermidine (Spd) on NO generation and the function of Spd-induced NO in the tolerance of tomato seedling under chilling stress. Spd increased NO release via the nitric oxide synthase (NOS)-like and nitrate reductase (NR) enzymatic pathways in the seedlings, whereas Put had no such effect. Moreover, H2O2 might act as an upstream signal to stimulate NO production. Both exogenous NO donor (sodium nitroprusside (SNP)) and Spd enhanced chilling tolerance in tomato, thereby protecting the photosynthetic system from damage. Compared to chilling treatment alone, Spd enhanced the gene expressions of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and their enzyme activities in tomato leaves. However, a scavenger or inhibitor of NO abolished Spd-induced chilling tolerance and blocked the increased expression and activity due to Spd of these antioxidant enzymes in tomato leaves under chilling stress. The results showed that NO induced by Spd plays a crucial role in tomato's response to chilling stress.

  19. Nitric oxide and heat shock protein 90 co-regulate temperature-induced bleaching in the soft coral Eunicea fusca

    Science.gov (United States)

    Ross, Cliff

    2014-06-01

    Coral bleaching represents a complex physiological process that is affected not only by environmental conditions but by the dynamic internal cellular biology of symbiotic dinoflagellates ( Symbiodinium spp.) and their cnidarian hosts. Recently, nitric oxide (NO) has emerged as a key molecule involved with the expulsion of Symbiodinium from host cnidarian cells. However, the site of production remains under debate, and the corresponding signaling pathways within and between host and endosymbiont remain elusive. In this study, using freshly isolated Symbiodinium from the soft coral Eunicea fusca, I demonstrate that thermally induced stress causes an upregulation in Symbiodinium heat shock protein 90 (Hsp90). In turn, Hsp90 shows a concomitant ability to enhance the activity of a constitutively expressed isoform of NO synthase. The resulting production of NO constitutes a signaling molecule capable of inducing Symbiodinium expulsion. Using nitric oxide synthase (NOS) and Hsp90 polyclonal antibodies, thermal stress-induced Hsp90 was shown to co-immunoprecipitate with a constitutive isoform of NOS. The specific blocking of Hsp90 activity, with the Hsp90 inhibitor geldanamycin, was capable of inhibiting NO production implicating the involvement of a coordinated regulatory system. These results have strong evolutionary implications for Hsp90-NOS chaperone complexes among biological kingdoms and provide evidence for a new functional role in symbiotic associations.

  20. Hepatoprotective Effect of Opuntia robusta and Opuntia streptacantha Fruits against Acetaminophen-Induced Acute Liver Damage

    NARCIS (Netherlands)

    Gonzalez Ponce, Herson Antonio; Consolacion Martinez-Saldana, Maria; Rosa Rincon-Sanchez, Ana; Teresa Sumaya-Martinez, Maria; Buist-Homan, Manon; Faber, Klaas Nico; Moshage, Han; Jaramillo-Juarez, Fernando

    2016-01-01

    Acetaminophen (APAP)-induced acute liver failure (ALF) is a serious health problem in developed countries. N-acetyl-L-cysteine (NAC), the current therapy for APAP-induced ALF, is not always effective, and liver transplantation is often needed. Opuntia spp. fruits are an important source of nutrients

  1. Hepatoprotective Effect of Opuntia robusta and Opuntia streptacantha Fruits against Acetaminophen-Induced Acute Liver Damage

    NARCIS (Netherlands)

    Antonio Gonzalez-Ponce, Herson; Consolacion Martinez-Saldana, Maria; Rosa Rincon-Sanchez, Ana; Teresa Sumaya-Martinez, Maria; Buist-Homan, Manon; Faber, Klaas Nico; Moshage, Han; Jaramillo-Juarez, Fernando

    2016-01-01

    Acetaminophen (APAP)-induced acute liver failure (ALF) is a serious health problem in developed countries. N-acetyl-L-cysteine (NAC), the current therapy for APAP-induced ALF, is not always effective, and liver transplantation is often needed. Opuntia spp. fruits are an important source of nutrients

  2. Endothelial dysfunction in high fructose containing diet fed rats: Increased nitric oxide and decreased endothelin-1 levels in liver tissue

    Directory of Open Access Journals (Sweden)

    Zeki Arı

    2010-09-01

    Full Text Available Objectives: Dietary high fructose consumption which is closely associated with endothelial dysfunction via insulin re-sistance has recently increased in developed countries. Insulin resistance has a promoter effect on many metabolic disorders such as syndrome X, polycystic ovary syndrome, Type 2 diabetes mellitus etc. Our aim in this study is to understand the impact of increased fructose intake on metabolisms of glucose, insulin and endothelial dysfunction by measuring nitric oxide (NO and endothelin-1 (ET-1 levels in hepatic tissue which is crucial in fructose metabolism.Materials and Methods: We designed an animal study to understand increased fructose intake on hepatic endothe-lium. Twenty adult male albino rats were divided into two groups; the study group (group 1, n=10 received isocaloric fructose enriched diet (fructose-fed rats, containing 18.3% protein, 60.3% fructose and 5.2% fat while the control group received purified regular chow (group 2, n=10 for 2 weeks. After feeding period, blood and hepatic tissue samples were collected and glucose, insulin, NO and ET-1 levels were analysed.Results: We found increased fasting glucose and insulin levels and impaired glucose tolerance in fructose fed rats. Higher NO and lower ET–1 levels were also detected in hepatic tissue samples of the group 1.Conclusion: Increased fructose consumption has deleterious effects on glucose tolerance, insulin resistance and may cause to endothelial dysfunction.

  3. Quiescent interplay between inducible nitric oxide synthase and tumor necrosis factor-alpha: influence on transplant graft vasculopathy in renal allograft dysfunction.

    Science.gov (United States)

    Elahi, Maqsood M; Matata, Bashir M; Hakim, Nadey S

    2006-06-01

    A healthy endothelium is essential for vascular homeostasis, and preservation of endothelial cell function is critical for maintaining transplant allograft function. Damage to the microvascular endothelial cells is now regarded as a characteristic feature of acute vascular rejection, an important predictor of graft loss. It is also linked with transplant vasculopathy, often associated with chronic allograft nephropathy. Large bursts of nitric oxide in infiltrating monocytes/macrophages modulated by inducible nitric oxide synthase are considered pivotal in driving this mechanism. Indeed, it has been shown recently that increased circulating levels of tumor necrosis factor-alpha in the rejecting kidneys are largely responsible for triggering inducible nitric oxide synthase expression. This in turn suggests that several structural and functional features of graft rejection could be mediated by tumor necrosis factor-alpha. Despite the large body of evidence that supports immunologic involvement, knowledge concerning the cellular and biochemical mechanisms for nephritic cell dysfunction and death is incomplete. The role of tumor necrosis factor-alpha in mediating pathophysiological activity of inducible nitric oxide synthase during transplant vasculopathy remains contentious. Here, we discuss the effect of inducible nitric oxide synthase and tumor necrosis factor-alpha interaction on progressive damage to glomerular and vascular structures during renal allograft rejection. Selective inhibition of inducible nitrous oxide synthase and tumor necrosis factor-alpha as a potential therapy for ameliorating endothelial dysfunction and transplant graft vasculopathy is also discussed.

  4. Hepatocyte growth factor gene therapy prevents radiation-induced liver damage

    Institute of Scientific and Technical Information of China (English)

    Chau-Hua Chi; I-Li Liu; Wei-Yu Lo; Bor-Song Liaw; Yu-Shan Wang; Kwan-Hwa Chi

    2005-01-01

    AIM: To transfer human HGF gene into the liver of rats by direct electroporation as a means to prevent radiationinduced liver damage.METHODS: Rat whole liver irradiation model was accomplished by intra-operative approach. HGF plasmid was injected into liver and transferred by electroporation using a pulse generator. Control rats (n = 8) received electrogene therapy (EGT) vehicle plasmid and another 8rats received HGF-EGT 100 μg 48 h before WLIR.Expression of HGF in liver was examined by RT-PCR and ELISA methods. Apoptosis was determined by TUNEL assay. Histopathology was evaluated 10 wk after whole liver irradiation.RESULTS: Marked decrease of apoptotic cells and downregulation of transforming growth factor-beta 1 (TGF-β1)mRNA were observed in the HGF-EGT group 2 d after liver irradiation compared to control animals. Less evidence of radiation-induced liver damage was observed morphologically in liver specimen 10 wk after liver irradiation and longer median survival time was observed from HGF-EGT group (14 wk) compared to control rats (5 wk). (P = 0.031).CONCLUSION: For the first time it has been demonstrated that HGF-EGT would prevent liver from radiation-induced liver damage by preventing apoptosis and down-regulation of TGF-β1.

  5. Anti-inflammatory effect of Mentha longifolia in lipopolysaccharide-stimulated macrophages: reduction of nitric oxide production through inhibition of inducible nitric oxide synthase.

    Science.gov (United States)

    Karimian, Parastoo; Kavoosi, Gholamreza; Amirghofran, Zahra

    2013-01-01

    Mentha longifolia is an aromatic plant used in flavoring and preserving foods and as an anti-inflammatory folk medicine remedy. The present study assessed the effects of M. longifolia extracts, including essential oil and crude methanol extract and its fractions (ethyl acetate, butanol and hexane), on nitric oxide (NO) production and inducible NO synthase (iNOS) mRNA expression in lipopolysaccharide (LPS)-stimulated J774A.1 cells using real-time polymerase chain reaction (PCR). The cytotoxic effects of the extracts on the cells were examined and non-cytotoxic concentrations (<0.2 mg/ml) were used to examine their effects on NO production and iNOS mRNA expression. Only the hexane fraction that contained high levels of phenolic and flavonoid compounds at concentrations from 0.05-0.20 mg/ml significantly reduced NO production in LPS-stimulated cells (p < 0.001). Real-time PCR analysis indicated the ability of this fraction at the same concentrations to significantly decrease iNOS as well as TNFα mRNA expression in the cells (p < 0.001). All extracts were able to scavenge NO radicals in a concentration-dependent manner. At concentrations greater than 0.2 mg/ml, total radicals were 100% scavenged. In conclusion, M. longifolia possibly reduces NO secretion in macrophages by scavenging NO and inhibiting iNOS mRNA expression, and also decreases TNFα pro-inflammatory cytokine expression, thus showing its usefulness in the inflammatory disease process.

  6. Nitric Oxide Reduces Hydrogen Peroxide Accumulation Involved in Water Stress-induced Subcellular Anti-oxidant Defense in Maize Plants

    Institute of Scientific and Technical Information of China (English)

    Jianrong Sang; Mingyi Jiang; Fan Lin; Shucheng Xu; Aying Zhang; Mingpu Tan

    2008-01-01

    Nitric oxide (NO) Is a bioactive molecule involved in many biological events, and has been reported as pro-oxidant as well as anti-oxidant in plants. In the present study, the sources of NO production under water stress, the role of NO in water stress-induced hydrogen peroxide (H2O2) accumulation and subcellular activities of anti-oxidant enzymes in leaves of maize (Zea mays L.) plants were investigated. Water stress Induced defense increases in the generation of NO In maize mesphyll cells and the activity of nitric oxide synthase (NOS) in the cytosolic and microsomal fractions of maize leaves. Water stress-induced defense increases in the production of NO were blocked by pretreatments with Inhibitors of NOS and nitrate reductase (NR), suggesting that NO is produced from NOS and NR in leaves of maize plants exposed to water stress. Water stress also induced increases in the activities of the chloroplastic and cytosolic anti-oxidant enzymes superoxide dismutase (SOD), ascorbate peroxidass (APX), and glutathione reductase (GR), and the increases in the activities of anti-oxidant enzymes were reduced by pretreatments with inhibitors of NOS and NR. Exogenous NO increases the activities of water stress-induced subcellular anti-oxidant enzymes, which decreases accumulation of H2O2. Our results suggest that NOS and NR are involved in water strese-induced NO production and NOS is the major source of NO. The potential ability of NO to scavenge H2O2 is, at least in part, due to the induction of a subcellular anti-oxidant defense.

  7. Attenuation of acute nitrogen mustard-induced lung injury, inflammation and fibrogenesis by a nitric oxide synthase inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Malaviya, Rama; Venosa, Alessandro [Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854 (United States); Hall, LeRoy [Drug Safety Sciences, Johnson and Johnson, Raritan, NJ 08869 (United States); Gow, Andrew J. [Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854 (United States); Sinko, Patrick J. [Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854 (United States); Laskin, Jeffrey D. [Department of Environmental and Occupational Medicine, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ 08854 (United States); Laskin, Debra L., E-mail: laskin@eohsi.rutgers.edu [Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854 (United States)

    2012-12-15

    Nitrogen mustard (NM) is a toxic vesicant known to cause damage to the respiratory tract. Injury is associated with increased expression of inducible nitric oxide synthase (iNOS). In these studies we analyzed the effects of transient inhibition of iNOS using aminoguanidine (AG) on NM-induced pulmonary toxicity. Rats were treated intratracheally with 0.125 mg/kg NM or control. Bronchoalveolar lavage fluid (BAL) and lung tissue were collected 1 d–28 d later and lung injury, oxidative stress and fibrosis assessed. NM exposure resulted in progressive histopathological changes in the lung including multifocal lesions, perivascular and peribronchial edema, inflammatory cell accumulation, alveolar fibrin deposition, bronchiolization of alveolar septal walls, and fibrosis. This was correlated with trichrome staining and expression of proliferating cell nuclear antigen (PCNA). Expression of heme oxygenase (HO)-1 and manganese superoxide dismutase (Mn-SOD) was also increased in the lung following NM exposure, along with levels of protein and inflammatory cells in BAL, consistent with oxidative stress and alveolar-epithelial injury. Both classically activated proinflammatory (iNOS{sup +} and cyclooxygenase-2{sup +}) and alternatively activated profibrotic (YM-1{sup +} and galectin-3{sup +}) macrophages appeared in the lung following NM administration; this was evident within 1 d, and persisted for 28 d. AG administration (50 mg/kg, 2 ×/day, 1 d–3 d) abrogated NM-induced injury, oxidative stress and inflammation at 1 d and 3 d post exposure, with no effects at 7 d or 28 d. These findings indicate that nitric oxide generated via iNOS contributes to acute NM-induced lung toxicity, however, transient inhibition of iNOS is not sufficient to protect against pulmonary fibrosis. -- Highlights: ► Nitrogen mustard (NM) induces acute lung injury and fibrosis. ► Pulmonary toxicity is associated with increased expression of iNOS. ► Transient inhibition of iNOS attenuates acute

  8. Effects of exercise training on stress-induced vascular reactivity alterations: role of nitric oxide and prostanoids

    Directory of Open Access Journals (Sweden)

    Thiago Bruder-Nascimento

    2015-06-01

    Full Text Available Background: Physical exercise may modify biologic stress responses. Objective: To investigate the impact of exercise training on vascular alterations induced by acute stress, focusing on nitric oxide and cyclooxygenase pathways. Method: Wistar rats were separated into: sedentary, trained (60-min swimming, 5 days/week during 8 weeks, carrying a 5% body-weight load, stressed (2 h-immobilization, and trained/stressed. Response curves for noradrenaline, in the absence and presence of L-NAME or indomethacin, were obtained in intact and denuded aortas (n=7-10. Results: None of the procedures altered the denuded aorta reactivity. Intact aortas from stressed, trained, and trained/stressed rats showed similar reduction in noradrenaline maximal responses (sedentary 3.54±0.15, stressed 2.80±0.10*, trained 2.82±0.11*, trained/stressed 2.97± 0.21*, *P<0.05 relate to sedentary. Endothelium removal and L-NAME abolished this hyporeactivity in all experimental groups, except in trained/stressed rats that showed a partial aorta reactivity recovery in L-NAME presence (L-NAME: sedentary 5.23±0,26#, stressed 5.55±0.38#, trained 5.28±0.30#, trained/stressed 4.42±0.41, #P<0.05 related to trained/stressed. Indomethacin determined a decrease in sensitivity (EC50 in intact aortas of trained rats without abolishing the aortal hyporeactivity in trained, stressed, and trained/stressed rats. Conclusions: Exercise-induced vascular adaptive response involved an increase in endothelial vasodilator prostaglandins and nitric oxide. Stress-induced vascular adaptive response involved an increase in endothelial nitric oxide. Beside the involvement of the endothelial nitric oxide pathway, the vascular response of trained/stressed rats involved an additional mechanism yet to be elucidated. These findings advance on the understanding of the vascular processes after exercise and stress alone and in combination.

  9. Regulation of p53 by activated protein kinase C-delta during nitric oxide-induced dopaminergic cell death.

    Science.gov (United States)

    Lee, Sung-Jin; Kim, Dong-Chan; Choi, Bo-Hwa; Ha, Hyunjung; Kim, Kyong-Tai

    2006-01-27

    Selective cell death of dopaminergic neurons in the substantia nigra is the major cause of Parkinson disease. Current evidence suggests that this cell death could be mediated by nitric oxide by-products such as nitrate and peroxynitrite. Because protein kinase C (PKC)-delta is implicated in apoptosis of various cell types, we studied its roles and activation mechanisms in nitric oxide (NO)-induced apoptosis of SN4741 dopaminergic cells. When cells were treated with sodium nitroprusside (SNP), a NO donor, endogenous PKC-delta was nitrated and activated. Immunoprecipitation revealed that p53 co-immunoprecipitated with PKC-delta and was phosphorylated at the 15th serine residue in SNP-treated cells. An in vitro kinase assay revealed that p53 was directly phosphorylated by SNP-activated PKC-delta. The p53 Ser-15 phosphorylation was suppressed in SNP-treated cells when the NO-mediated activation of PKC-delta was inhibited by rottlerin or (-)-epigallocatechin gallate. Within 3 h of p53 phosphorylation, its protein levels increased because of decreased ubiquitin-dependent proteosomal proteolysis, whereas the protein levels of MDM2, ubiquitin-protein isopeptide ligase, were down-regulated in a p53 phosphorylation-dependent fashion. Taken together, these results demonstrate that nitration-mediated activation of PKC-delta induces the phosphorylation of the Ser-15 residue in p53, which increases its protein stability, thereby contributing to the nitric oxide-mediated apoptosis-like cell death pathway. These findings may be expanded to provide new insight into the cellular mechanisms of Parkinson disease.

  10. Influence of cholesterol and fish oil dietary intake on nitric oxide-induced apoptosis in vascular smooth muscle cells.

    Science.gov (United States)

    Perales, Sonia; Alejandre, Ma José; Palomino-Morales, Rogelio; Torres, Carolina; Linares, Ana

    2010-04-01

    Apoptosis of vascular smooth muscle cells (SMC) is critically involved in the progression of atherosclerosis. We previously reported that dietary cholesterol intake induces changes in SMC at molecular and gene expression levels. The objectives of the present study were to investigate the differential response to nitric oxide of vascular SMC obtained from chicks after cholesterol and fish oil dietary intake and to examine effects on the main pro-apoptotic and anti-apoptotic genes. Dietary cholesterol intake reduced the Bcl-2/Bax (anti-apoptotic/pro-apoptotic) protein ratio in SMC, making them more susceptible to apoptosis. When cholesterol was withdrawn and replaced with a fish oil-enriched diet, the Bcl-xl/Bax protein ratio significantly increased, reversing the changes induced by cholesterol. The decrease in c-myc gene expression after apoptotic stimuli and the increase in Bcl-xl/Bax ratio indicate that fish oil has a protective role against apoptosis in SMC. Nitroprussiate-like nitric oxide donors exerted an intensive action on vascular SMC cultures. However, SMC-C (isolated from animals fed with control diet) and SMC-Ch (isolated from animals fed with cholesterol-enriched diet) responded differently to nitric oxide, especially in their bcl-2 and bcl-xl gene expression. SMC isolated from animals fed with cholesterol-enriched and then fish oil-enriched diet (SMC-Ch-FO cultures) showed an intermediate apoptosis level (Bcl-2/Bax ratio) between SMC-C and SMC-Ch, induction of c-myc expression and elevated p53 expression. These findings indicate that fish oil protects SMC against apoptosis.

  11. DOWN-REGULATION OF INDUCIBLE NITRIC OXIDE SYNTHASE EXPRESSION BY INOSITOL HEXAPHOSPHATE IN HUMAN COLON CANCER CELLS.

    Science.gov (United States)

    Kapral, Małgorzata; Wawszczyk, Joanna; Sośnicki, Stanisław; Węglarz, Ludmiła

    2015-01-01

    Inflammatory bowel disease (IBD) is chronic inflammatory condition associated with increased risk of developing colorectal cancer. A number of mediators of inflammation, such as pro-inflammatory cytokines, prostaglandins and nitric oxide have been involved in carcinogenesis, especially in the promotion and progression stages. NO is synthesized from L-arginine by constitutively expressed endothelial and neuronal nitric oxide synthases (eNOS and nNOS, respectively) and an inducible NOS (iNOS) isoform expressed under inflammatory conditions. A selective inhibitors of iNOS could be, therefore, considered to be good candidates as chemopreventive agents against colon cancer. In this study, the effect of inositol hexaphosphate (IP6), dietary phytochemical, on the mRNA expression of iNOS stimulated with bacterial lipopolysaccharides (Escherichia coli and Salmonella typhimurium) and IL-1β in intestinal cells Caco-2 for 6 and 12 h was investigated. A transcription level of iNOS with the use real time QRT-PCR technique was determined in cells treated with 1 and 2.5 mM IP6. Stimulation of Caco-2 with pro-inflammatory factors (LPS and IL-1β) resulted in an up-expression of iNOS mRNA at 6 and 12 h. Cells exposed to IP6 only revealed significant reduction in iNOS gene transcription after 12 h. A decrease in iNOS transcription by IP6 following the gene induction by proinflammatory agents in 6 and 12 h lasting cultures was also determined. The findings of this study suggest that one of the anti-cancer and anti-inflammatory abilities of IP6 can be realized by suppressing the expression of gene encoding inducible nitric oxide synthase isoform at the transcriptional level.

  12. Oligonol Ameliorates CCl4-Induced Liver Injury in Rats via the NF-Kappa B and MAPK Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Jeonghyeon Bak

    2016-01-01

    Full Text Available Oxidative stress is thought to be a key risk factor in the development of hepatic diseases. Blocking or retarding the reactions of oxidation and the inflammatory process by antioxidants could be a promising therapeutic intervention for prevention or treatment of liver injuries. Oligonol is a low molecular weight polyphenol containing catechin-type monomers and oligomers derived from lychee fruit. In this study, we investigated the anti-inflammatory effect of oligonol on carbon tetrachloride- (CCl4- induced acute hepatic injury in rats. Oral administration of oligonol (10 or 50 mg/kg reduced CCl4-induced abnormalities in liver histology and serum AST and serum ALT levels. Oligonol treatment attenuated the CCl4-induced production of inflammatory mediators, including TNF-α, IL-1β, cyclooxygenase-2 (COX-2, and inducible nitric oxide synthase (iNOS mRNA levels. Western blot analysis showed that oligonol suppressed proinflammatory nuclear factor-kappa B (NF-κB p65 activation, phosphorylation of extracellular signal-regulated kinase (ERK, c-Jun NH2-terminal kinase (JNK, and p38 mitogen-activated protein kinases (MAPKs as well as Akt. Oligonol exhibited strong antioxidative activity in vitro and in vivo, and hepatoprotective activity against t-butyl hydroperoxide-induced HepG2 cells. Taken together, oligonol showed antioxidative and anti-inflammatory effects in CCl4-intoxicated rats by inhibiting oxidative stress and NF-κB activation via blockade of the activation of upstream kinases including MAPKs and Akt.

  13. Animals models of gastrointestinal and liver diseases. Animal models of alcohol-induced liver disease: pathophysiology, translational relevance, and challenges.

    Science.gov (United States)

    Mathews, Stephanie; Xu, Mingjiang; Wang, Hua; Bertola, Adeline; Gao, Bin

    2014-05-15

    Over the last four decades, chronic ethanol feeding studies in rodents using either ad libitum feeding or intragastric infusion models have significantly enhanced our understanding of the pathogenesis of alcoholic liver disease (ALD). Recently, we developed a chronic plus binge alcohol feeding model in mice that is similar to the drinking patterns of many alcoholic hepatitis patients: a history of chronic drinking and recent excessive alcohol consumption. Chronic+binge ethanol feeding synergistically induced steatosis, liver injury, and neutrophil infiltration in mice, which may be useful for the study of early alcoholic liver injury and inflammation. Using this chronic+binge model, researchers have begun to identify novel mechanisms that participate in the pathogenesis of alcoholic liver injury, thereby revealing novel therapeutic targets. In this review article, we briefly discuss several mouse models of ALD with a focus on the chronic+binge ethanol feeding model.

  14. Propylthiouracyl-induced severe liver toxicity: An indication for alanine aminotransferase monitoring?

    Institute of Scientific and Technical Information of China (English)

    M Benyounes; C Sempoux; C Daumerie; J Rahier; AP Geubel

    2006-01-01

    Propylthiouracyl (PTU)-related liver toxicity is likely to occur in about 1% of treated patients. In case of acute or subacute hepatitis, liver failure may occur in about one third. We report two further cases of PTU-induced subacute hepatitis, in whom the delay between occurrence of liver damage after the initiation of treatment, the underestimation of its severity and the delayed withdrawal of the drug were all likely responsible for liver failure.The high incidence of liver toxicity related to PTU, its potential severity and delayed occurrence after initiation of treatment are in favor of monthly alanine aminotransferase monitoring, at least during the first six months of therapy.

  15. Interleukin-1 beta-induced nitric oxide production from isolated rat islets is modulated by D-glucose and 3-isobutyl-1-methyl xanthine

    DEFF Research Database (Denmark)

    Andersen, H U; Mauricio, D; Karlsen, Allan Ertman

    1996-01-01

    Interleukin-1 beta has been proposed to cause selective beta-cell destruction via the induction of nitric oxide synthesis. The cytotoxic effect of interleukin-1 beta is modulated by the concentration of D-glucose in the medium. The aim of this study was to investigate if D-glucose-mediated modula......Interleukin-1 beta has been proposed to cause selective beta-cell destruction via the induction of nitric oxide synthesis. The cytotoxic effect of interleukin-1 beta is modulated by the concentration of D-glucose in the medium. The aim of this study was to investigate if D...... effects on acute insulin release was found at high (28 mmol/l) concentrations of D-glucose, and blocking nitrite production by the L-arginine analog aminoguanidine, which selectively inhibits the cytokine-inducible nitric oxide synthase, did not result in protection against the inhibitory action...... that could be reproduced by the cAMP analog dibutyryl cAMP. Addition of 3-isobutyl-1-methyl xanthine resulted in a threefold reduction in the mRNA level of interleukin-1 beta-induced inducible nitric oxide synthase. We conclude that interleukin-1 beta-induced islet nitric oxide synthesis is augmented by D...

  16. Inhibition of neuronal and inducible nitric oxide synthase does not affect the analgesic effects of NMDA antagonists in visceral inflammatory pain.

    Science.gov (United States)

    Srebro, Dragana; Vučković, Sonja; Prostran, Milica

    2016-01-01

    Previously we described the antinociceptive effect of magnesium sulfate and dizocilpine (MK-801) in the visceral and somatic rat models of pain. In the somatic model of pain, we established the influence of selective inhibitors of neuronal and inducible nitric oxide synthase on the antihyperalgesic effects of magnesium sulfate and dizocilpine. Therefore, the objective of the present study was to determine in the rat model of visceral pain whether same mechanisms are involved in the antinociceptive action of magnesium sulfate and dizocilpine. Analgesic activity was assessed using the acetic acid-induced writhing test in rats. Subcutaneous injection of either magnesium sulfate (15 mg/kg) or dizocilpine (0.01 mg/kg) decreased the number of writhes by about 60 and 70%, respectively. The role of nitric oxide on the effects of magnesium sulfate and dizocilpine was evaluated using selective inhibitor of neuronal (N-ω-Propyl-L-arginine hydrochloride (L-NPA)) and inducible (S-methylisothiourea (SMT)) nitric oxide synthase, which per se did not affect the number of writhes. We observed that the antinociceptive effect of magnesium sulfate or dizocilpine did not change in the presence of L-NPA (2 and 10 mg/kg, i.p.) and SMT (0.015 and 10 mg/kg, i.p.). We conclude that, nitric oxide produced by neuronal and inducible nitric oxide synthase does not modulate the effects of magnesium sulfate and dizocilpine in the visceral inflammatory model of pain in the rat.

  17. Neutrophil elastase contributes to the development of ischemia/reperfusion-induced liver injury by decreasing the production of insulin-like growth factor-I in rats.

    Science.gov (United States)

    Kawai, Miho; Harada, Naoaki; Takeyama, Hiromitsu; Okajima, Kenji

    2010-06-01

    Neutrophil elastase (NE) decreases the endothelial production of prostacyclin (PGI(2)) through the inhibition of endothelial nitric oxide synthase (NOS) activation and thereby contributes to the development of ischemia/reperfusion (I/R)-induced liver injury. We previously demonstrated that calcitonin gene-related peptide (CGRP) released from sensory neurons increases the insulin-like growth factor- I (IGF-I) production and thereby reduces I/R-induced liver injury. Because PGI(2) is capable of stimulating sensory neurons, we hypothesized that NE contributes to the development of I/R-induced liver injury by decreasing IGF-I production. In the present study, we examined this hypothesis in rats subjected to hepatic I/R. Ischemia/reperfusion-induced decreases of hepatic tissue levels of CGRP and IGF-I were prevented significantly by NE inhibitors, sivelestat, and L-658, 758, and these effects of NE inhibitors were reversed completely by the nonselective cyclooxygenase inhibitor indomethacin (IM) and the nonselective NOS inhibitor L-NAME but not by the selective inducible NOS inhibitor 1400W. I/R-induced increases of hepatic tissue levels of caspase-3, myeloperoxidase and the number of apoptotic cells were inhibited by NE inhibitors, and these effects of NE inhibitors were reversed by IM and L-NAME but not by 1400W. Administration of iloprost, a stable PGI(2) analog, produced effects similar to those induced by NE inhibitors. Taken together, these observations strongly suggest that NE may play a critical role in the development of I/R-induced liver injury by decreasing the IGF-I production through the inhibition of sensory neuron stimulation, which may lead to an increase of neutrophil accumulation and hepatic apoptosis through activation of caspase-3 in rats.

  18. Nitric oxide inhibited the melanophore aggregation induced by extracellular calcium concentration in snakehead fish, Channa punctatus.

    Science.gov (United States)

    Biswas, Saikat P; Palande, Nikhil V; Jadhao, Arun G

    2011-12-01

    We studied the role of nitric oxide (NO) and extra-cellular Ca(2+) on the melanophores in Indian snakehead teleost, Channa punctatus. Increase of Ca(2+) level in the external medium causes pigment aggregation in melanophores. This pigment-aggregating effect was found to be inhibited when the external medium contained spontaneous NO donor, sodium nitro prusside (SNP) at all the levels of concentration tested. Furthermore, it has been observed that SNP keeps the pigment in dispersed state even after increasing the amount of Ca(2+). In order to test whether NO donor SNP causes dispersion of pigments or not is checked by adding the inhibitor of nitric oxide synthase, N-omega-Nitro-L-arginine (L-NNA) in the medium. It has been noted that the inhibitor L-NNA blocked the effect of NO donor SNP causing aggregation of pigments. In that way NO is inhibiting the effect of extracellular Ca(2+), keeping the pigment dispersed.

  19. An essential role of endothelium-derived nitric oxide in vasorelaxations induced by black tea polyphenols

    Institute of Scientific and Technical Information of China (English)

    HUANG Yu

    2008-01-01

    Green tea has received much attention as protective agent against cardiovascular disease and cancer, the two primary targets of preventive medicine. Since our first demonstration in 1999 of the involvement of endothelium-derived nitric oxide in the acute vasodilator effect of green tea polyphenols, several new vascular protective effects of green tea catechins have been identified. Theaflavins are another class of polyphenol pigments found in black tea, however, little is known about their bioactivity in the vascular system. We have recently demonstrated that black tea and its theaflavins cause relaxations of rat aortas via endothelial nitric oxide-dependent mechanisms and the tea polyphenols are very effective in protecting endothelial function agonist oxidative stress. The present results support the vascular benefit of consumption of black tea, which is equal to that of drinking green tea in terms of their endothelial cell protection and antioxidant capacity.

  20. Nitric Oxide Mediates the Stress Response Induced by Diatom Aldehydes in the Sea Urchin Paracentrotus lividus

    OpenAIRE

    Giovanna Romano; Maria Costantini; Isabella Buttino; Adrianna Ianora; Anna Palumbo

    2011-01-01

    Diatoms are ubiquitous and abundant primary producers that have been traditionally considered as a beneficial food source for grazers and for the transfer of carbon through marine food webs. However, many diatom species produce polyunsaturated aldehydes that disrupt development in the offspring of grazers that feed on these unicellular algae. Here we provide evidence that production of the physiological messenger nitric oxide increases after treatment with the polyunsaturated aldehyde decadie...

  1. Expression of inducible nitric oxide synthase and cyclooxygenase-2 in pancreatic adenocarcinoma:Correlation with microvessel density

    Institute of Scientific and Technical Information of China (English)

    Hans U. Kasper; Hella Wolf; Uta Drebber; Helmut K. Wolf; Michael A. Kern

    2004-01-01

    AIM: Cyclooxygenases (COX) are key enzymes for conversion of arachidonic acid to prostaglandins. Nitric oxide synthase (NOS) is the enzyme responsible for formation of nitric oxide.Both have constitutive and inducible isoforms. The inducible isoforms (iNOS and COX-2) are of great interest as regulators of tumor angiogenesis, tumorigenesis and inflammatory processes. This study was to clarify their role in pancreatic adenocarcinomas.METHODS: We investigated the immunohistochemical iNOS and COX-2 expression in 40 pancreatic ducal adenocarcinomas of different grade and stage. The results were compared with microvessel density and clinicopathological data.RESULTS: Twenty-one (52.5%) of the cases showed iNOS expression, 15 (37.5%) of the cases were positive for COX-2.The immunoreaction was heterogeneously distributed within the tumors. Staining intensity was different between the tumors. No correlation between iNOS and COX-2 expression was seen. There was no relationship with microvessel density.However, iNOS positive tumors developed more often distant metastases and the more malignant tumors showed a higher COX-2 expression. There was no correlation with other clinicopathological data.CONCLUSION: Approximately half of the cases expressed iNOS and COX-2. These two enzymes do not seem to be the key step in angiogenesis or carcinogenesis of pancreatic adenocarcinomas. Due to a low prevalence of COX-2expression, chemoprevention of pancreatic carcinomas by COX-2 inhibitors can only achieve a limited success.

  2. Nitric oxide alleviates aluminum-induced oxidative damage through regulating the ascorbate-glutathione cycle in roots of wheat

    Institute of Scientific and Technical Information of China (English)

    Chengliang Sun; Lijuan Liu; Yan Yu; Wenjing Liu; Lingli Lu; Chongwei Jin; Xianyong Lin

    2015-01-01

    The possible association with nitric oxide (NO) and ascorbate-glutathione (AsA-GSH) cycle in regulating aluminum (Al) tolerance of wheat (Triticum aestivum L.) was investigated using two genotypes with different Al resistance. Exposure to Al inhibited root elongation, and triggered lipid peroxidation and oxidation of AsA to dehydroascorbate and GSH to glutathione disulfide in wheat roots. Exogenous NO significantly increased endogenous NO levels, and subsequently al eviated Al-induced inhibition of root elongation and oxidation of AsA and GSH to maintain the redox molecules in the reduced form in both wheat genotypes. Under Al stress, significantly increased activities and gene transcriptional levels of ascorbate peroxi-dase, glutathione reductase, and dehydroascorbate reductase, were observed in the root tips of the Al-tolerant genotype Jian-864. Nitric oxide application enhanced the activity and gene transcriptional level of these enzymes in both wheat geno-types. g-Glutamylcysteine synthetase was not significantly affected by Al or NO, but NO treatments increased the activity of glutathione peroxidase and glutathione S-transferase to a greater extent than the Al-treated wheat seedlings. Proline was significantly decreased by Al, while it was not affected by NO. These results clearly suggest that NO protects wheat root against Al-induced oxidative stress, possibly through its regulation of the AsA-GSH cycle.

  3. Safranal of Crocus sativus L. inhibits inducible nitric oxide synthase and attenuates asthma in a mouse model of asthma.

    Science.gov (United States)

    Bukhari, Syed Imran; Pattnaik, Bijay; Rayees, Sheikh; Kaul, Sanjana; Dhar, Manoj K

    2015-04-01

    The present study involves evaluation of antioxidant potential of Crocus sativus and its main constituents, safranal (SFN) and crocin (CRO), in bronchial epithelial cells, followed antiinflammatory potential of the active constituent safranal, in a murine model of asthma. To investigate the antioxidizing potential of Crocus sativus and its main constituents in bronchial epithelial cells, the stress was induced in these cells by a combination of different cytokines that resulted in an increase in nitric oxide production (NO), induced nitric oxide synthase (iNOS) levels, peroxynitrite ion generation, and cytochrome c release. Treatment with saffron and its constituents safranal and crocin resulted in a decrease of NO, iNOS levels, peroxynitrite ion generation, and prevented cytochrome c release. However, safranal significantly reduced oxidative stress in bronchial epithelial cells via iNOS reduction besides preventing apoptosis in these cells. In the murine model of asthma study, antiinflammatory role of safranal was characterized by increased airway hyper-responsiveness, airway cellular infiltration, and epithelial cell injury. Safranal pretreatment to these allergically inflamed mice lead to a significant decrease in airway hyper-responsiveness and airway cellular infiltration to the lungs. It also reduced iNOS production, bronchial epithelial cell apoptosis, and Th2 type cytokine production in the lungs.

  4. Synergistic Action between Jasmonic Acid and Nitric Oxide in Inducing Matrine Accumulation of Sophora flavescens Suspension Cells

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Secondary metabolites not only play important ecological roles in plants but also are important pharmaceutical and source compounds for derivative synthesis. Production of plant secondary metabolites is believed to be controlled by the endogenous signal network of plants. However, the molecular basis is still largely unknown. Here we show that matrine production of Sophora flavescens Ait. cells treated with low levels of jasmonic acid (JA) and nitric oxide (NO) is significantly increased although treatment with low concentrations of JA or NO alone has no effects on matrine production, showing that JA and NO may act synergistically in triggering matrine production. Moreover, treatment with NO triggers lipoxygenase(LOX) activity and enhances JA levels of the cells, showing that NO may activate the endogenous JA biosynthesis of S.flavescens cells. External application of JA induces nitric oxide synthase-like activities and stimulates NO generation of S. flavescens cells, which suggests that JA may trigger NO generation of the cells. Thus, the results reveal a mutually amplifying reaction between JA and NO in S. flavescens cells. Furthermore, JA and NO inhibitors suppress not only the mutually amplifying reaction between JA and NO but also the synergistic effects of NO and JA on matrine production.Therefore, the data demonstrate that the synergistic action of JA and NO in inducing matrine production might be due to the mutually amplifying reaction between JA and NO in the cells.

  5. Ethylene and nitric oxide interact to regulate the magnesium deficiency-induced root hair development in Arabidopsis.

    Science.gov (United States)

    Liu, Miao; Liu, Xing Xing; He, Xiao Lin; Liu, Li Juan; Wu, Hao; Tang, Cai Xian; Zhang, Yong Song; Jin, Chong Wei

    2017-02-01

    Nitric oxide (NO) and ethylene respond to biotic and abiotic stresses through either similar or independent processes. This study examines the mechanism underlying the effects of NO and ethylene on promoting root hair development in Arabidopsis under magnesium (Mg) deficiency. The interaction between NO and ethylene in the regulation of Mg deficiency-induced root hair development was investigated using NO- and ethylene-related mutants and pharmacological methods. Mg deficiency triggered a burst of NO and ethylene, accompanied by a stimulated development of root hairs. Interestingly, ethylene facilitated NO generation by activation of both nitrate reductase and nitric oxide synthase-like (NOS-L) in the roots of Mg-deficient plants. In turn, NO enhanced ethylene synthesis through stimulating the activities of 1-aminocyclopropane-1-carboxylate (ACC) oxidase and ACC synthase (ACS). These two processes constituted an NO-ethylene feedback loop. Blocking either of these two processes inhibited the stimulation of root hair development under Mg deficiency. In conclusion, we suggest that Mg deficiency increases the production of NO and ethylene in roots, each influencing the accumulation and role of the other, and thus these two signals interactively regulate Mg deficiency-induced root hair morphogenesis. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  6. Nitric oxide induces ataxia telangiectasia mutated (ATM) protein-dependent γH2AX protein formation in pancreatic β cells.

    Science.gov (United States)

    Oleson, Bryndon J; Broniowska, Katarzyna A; Schreiber, Katherine H; Tarakanova, Vera L; Corbett, John A

    2014-04-18

    In this study, the effects of cytokines on the activation of the DNA double strand break repair factors histone H2AX (H2AX) and ataxia telangiectasia mutated (ATM) were examined in pancreatic β cells. We show that cytokines stimulate H2AX phosphorylation (γH2AX formation) in rat islets and insulinoma cells in a nitric oxide- and ATM-dependent manner. In contrast to the well documented role of ATM in DNA repair, ATM does not appear to participate in the repair of nitric oxide-induced DNA damage. Instead, nitric oxide-induced γH2AX formation correlates temporally with the onset of irreversible DNA damage and the induction of apoptosis. Furthermore, inhibition of ATM attenuates cytokine-induced caspase activation. These findings show that the formation of DNA double strand breaks correlates with ATM activation, irreversible DNA damage, and ATM-dependent induction of apoptosis in cytokine-treated β cells.

  7. Interleukin-1 beta-induced nitric oxide production from isolated rat islets is modulated by D-glucose and 3-isobutyl-1-methyl xanthine

    DEFF Research Database (Denmark)

    Andersen, H U; Mauricio, D; Karlsen, Allan Ertman

    1996-01-01

    Interleukin-1 beta has been proposed to cause selective beta-cell destruction via the induction of nitric oxide synthesis. The cytotoxic effect of interleukin-1 beta is modulated by the concentration of D-glucose in the medium. The aim of this study was to investigate if D......-glucose-mediated modulation of interleukin-1 beta effects on insulin release from isolated rat islets was related to modulation of nitric oxide production. Further, we wished to investigate the effects of agents increasing the intracellular concentration of cAMP on interleukin-1 beta-induced nitrite production. We...... demonstrated that D-glucose potentiated interleukin-1 beta-induced nitrite production in rat islets without affecting the mRNA level of the inducible nitric oxide synthase. This effect was dissociated from interleukin-1 beta action on insulin release, since a relative protection against interleukin-1 beta...

  8. The mechanism of the nitric oxide-mediated enhancement of tert-butylhydroperoxide-induced DNA single strand breakage

    Science.gov (United States)

    Guidarelli, Andrea; Clementi, Emilio; Sciorati, Clara; Cantoni, Orazio

    1998-01-01

    Caffeine (Cf) enhances the DNA cleavage induced by tert-butylhydroperoxide (tB-OOH) in U937 cells via a mechanism involving Ca2+-dependent mitochondrial formation of DNA-damaging species (Guidarelli et al., 1997b). Nitric oxide (NO) is not involved in this process since U937 cells do not express the constitutive nitric oxide synthase (cNOS).Treatment with the NO donors S-nitroso-N-acetyl-penicillamine (SNAP, 10 μM), or S-nitrosoglutathione (GSNO, 300 μM), however, potentiated the DNA strand scission induced by 200 μM tB-OOH. The DNA lesions generated by tB-OOH alone, or combined with SNAP, were repaired with superimposable kinetics and were insensitive to anti-oxidants and peroxynitrite scavengers but suppressed by iron chelators.SNAP or GSNO did not cause mitochondrial Ca2+ accumulation but their enhancing effects on the tB-OOH-induced DNA strand scission were prevented by ruthenium red, an inhibitor of the calcium uniporter of mitochondria. Furthermore, the enhancing effects of both SNAP and GSNO were identical to and not additive with those promoted by the Ca2+-mobilizing agents Cf or ATP.The SNAP- or GSNO-mediated enhancement of the tB-OOH-induced DNA cleavage was abolished by the respiratory chain inhibitors rotenone and myxothiazol and was not apparent in respiration-deficient cells.It is concluded that, in cells which do not express the enzyme cNOS, exogenous NO enhances the accumulation of DNA single strand breaks induced by tB-OOH via a mechanism involving inhibition of complex III. PMID:9846647

  9. Participación del óxido nítrico durante el desarrollo del absceso hepático amebiano Nitric oxide participation during amoebic liver abscess development

    Directory of Open Access Journals (Sweden)

    Joel Ramírez-Emiliano

    2007-04-01

    Full Text Available El óxido nítrico participa en funciones fisiológicas y fisiopatológicas, así como en el mecanismo de defensa del sistema inmunológico de mamíferos contra parásitos, virus y bacterias. La Entamoeba histolytica es un parásito protozoario causante de la amebiasis, la cual se caracteriza por el daño intestinal y la formación del absceso hepático amebiano (AHA. El desarrollo del absceso hepático amebiano en el hámster es similar al que desarrolla el humano, mientras que el ratón es resistente a la formación de este absceso, debido a un incremento en la producción de óxido nítrico. A diferencia del ratón, el desarrollo del absceso hepático amebiano en el hámster es debido a un exceso en la producción de óxido nítrico o posiblemente a una mayor susceptibilidad del hámster al daño producido por el óxido nítrico. Por lo tanto, sería importante realizar más estudios para determinar si en el humano, un exceso en la producción de óxido nítrico favorece la formación del absceso hepático amebiano.Nitric oxide participates in both physiological and pathophysiological functions, and it plays an important role in the mammalian immune system in killing or inhibiting the growth of many pathogens, including parasites, viruses and bacteria. Entamoeba histolytica is a protozoan parasite that causes amoebiasis, which is characterized by intestinal damage and amoebic liver abscess development. The development of amoebic liver abscess in hamsters is similar to that in humans, whereas mice are resistant to amoebic liver abscess development due to an increase in nitric oxide production. Unlike in mice, amoebic liver abscess development in hamsters is due to an excess in nitric oxide production or possibly to a greater susceptibility of the hamster to damage caused by nitric oxide. Therefore, it could be important to elucidate if, in humans, an excess in nitric oxide production favors amoebic liver abscess development.

  10. Phenotypic changes of human cells in human-rat liver during partial hepatectomy-induced regeneration

    Institute of Scientific and Technical Information of China (English)

    Yan Sun; Dong Xiao; Hong-An Li; Jin-Fang Jiang; Qing Li; Ruo-Shuang Zhang; Xi-Gu Chen

    2009-01-01

    AIM: To examine the human hepatic parenchymal and stromal components in rat liver and the phenotypic changes of human cells in liver of human-rat chimera (HRC) generated by in utero transplantation of human cells during partial hepatectomy (PHx)-induced liver regeneration. METHODS: Human hepatic parenchymal and stromal components and phenotypic changes of human cells during liver regeneration were examined by flow cytometry, in situ hybridization and immunohistochemistry. RESULTS: ISH analysis demonstrated human Alupositive cells in hepatic parenchyma and stroma of recipient liver. Functional human hepatocytes gener