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Milewski K, Czarnecka AM, Albrecht J, Zielińska M. Decreased Expression and Uncoupling of Endothelial Nitric Oxide Synthase in the Cerebral Cortex of Rats with Thioacetamide-Induced Acute Liver Failure. Int J Mol Sci 2021; 22:6662. [PMID: 34206365 PMCID: PMC8268495 DOI: 10.3390/ijms22136662] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/16/2021] [Accepted: 06/18/2021] [Indexed: 02/04/2023] Open
Abstract
Acute liver failure (ALF) is associated with deregulated nitric oxide (NO) signaling in the brain, which is one of the key molecular abnormalities leading to the neuropsychiatric disorder called hepatic encephalopathy (HE). This study focuses on the effect of ALF on the relatively unexplored endothelial NOS isoform (eNOS). The cerebral prefrontal cortices of rats with thioacetamide (TAA)-induced ALF showed decreased eNOS expression, which resulted in an overall reduction of NOS activity. ALF also decreased the content of the NOS cofactor, tetrahydro-L-biopterin (BH4), and evoked eNOS uncoupling (reduction of the eNOS dimer/monomer ratio). The addition of the NO precursor L-arginine in the absence of BH4 potentiated ROS accumulation, whereas nonspecific NOS inhibitor L-NAME or EDTA attenuated ROS increase. The ALF-induced decrease of eNOS content and its uncoupling concurred with, and was likely causally related to, both increased brain content of reactive oxidative species (ROS) and decreased cerebral cortical blood flow (CBF) in the same model.
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Affiliation(s)
| | | | | | - Magdalena Zielińska
- Department of Neurotoxicology, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego Str, 02-106 Warsaw, Poland; (K.M.); (A.M.C.); (J.A.)
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Pascuan CG, Simon EH, Genaro AM, Palumbo ML. Involvement of nitric oxide in improving stress-induced behavioural alteration by glatiramer acetate treatment in female BALB/c mice. Psychopharmacology (Berl) 2015; 232:1595-605. [PMID: 25373868 DOI: 10.1007/s00213-014-3791-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 10/25/2014] [Indexed: 11/26/2022]
Abstract
RATIONALE Oxidative stress and neurotrophins are among the most important factors involved in several pathophysiological brain processes. In addition, long-term exposure to stressful situations has deleterious effects on behaviour. We have previously shown that stressed female BALB/c mice show poor learning performance and that this behaviour is reversed by glatiramer acetate (GA) treatment. OBJECTIVES We investigated the involvement of the hippocampal oxidative status and neurotrophin levels in cognitive deficit and the improvement of this deficit by GA treatment in chronic stressed BALB/c mice. METHODS Female BALB/c mice were exposed to a chronic mild stress (CMS) model for 9 weeks. During the last 3 weeks of the stress exposure, one group of mice was subcutaneously injected four times with 100 μg GA/mouse. Following this period, behavioural studies were performed. The mice were then sacrificed, and biochemical studies were performed on the hippocampus. RESULTS The stressed mice exhibited a significant decline in their performance in the open-field and in object-in-place tasks. This decline was accompanied by an increase in reactive oxygen species (ROS) and a decrease in nitric oxide (NO) production by neuronal nitric oxide synthase (nNOS). Neither antioxidant defences nor neurotrophin protein levels were involved in this process. Interestingly, the administration of GA re-established the normal levels of ROS, restored nNOS activity and improved learning performance. CONCLUSIONS The GA treatment improved learning and memory in female BALB/c mice under chronic stress through a mechanism that involves the regulation of NO production, which in turn modulates the ROS levels.
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Affiliation(s)
- Cecilia Gabriela Pascuan
- CEFYBO-CONICET, 1ª. Cátedra de Farmacología, Facultad de Medicina, UBA, Paraguay 2155, C1121ABG, Ciudad Autónoma de Buenos Aires, Argentina
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Effect of biliary cirrhosis on neurogenic relaxation of rat gastric fundus and anococcygeus muscle: role of nitric oxide pathway. Dig Dis Sci 2014; 59:2675-81. [PMID: 24898099 DOI: 10.1007/s10620-014-3225-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 05/23/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND Cirrhosis, associated with a host of hemodynamic abnormalities, could affect the gastrointestinal (GI) tract motility. On the other hand, the nonadrenergic noncholinergic (NANC) neurotransmission has been shown to play a pivotal role in GI tract motility and has been linked with release of nitric oxide (NO) on electrical stimulation. In this study, we investigated the effect of biliary cirrhosis on the neurogenic relaxation of rat gastric fundus and anococcygeus muscle and also the possible role of nitric oxide system in this manner. METHODS Isolated gastric fundus and anococcygeus strips of sham-operated and biliary cirrhotic (4 weeks after bile duct ligation) rats were mounted under tension in a standard organ bath. Electrical stimulation was applied to obtain NANC-mediated relaxations in precontracted gastric fundus and anococcygeus muscle. The neurogenic relaxations were examined in the presence of different doses of NO synthase inhibitor, N (w)-Nitro-L-Arginine Methyl Ester (L-NAME). The concentration-dependent relaxant responses to the NO donor sodium nitroprusside were also evaluated. RESULTS The neurogenic relaxation of both gastric fundus and anococcygeus muscle was significantly (P < 0.001) increased in cirrhotic animals. L-NAME (0.03-1,000 µM) inhibited relaxations in both groups in a dose-dependent manner (P < 0.001), but cirrhotic groups were more resistant to the inhibitory effects of L-NAME (P < 0.01). Sodium nitroprusside-mediated relaxations were similar in two groups. CONCLUSIONS This study for the first time demonstrated that cirrhosis increases the NO-mediated neurogenic relaxation of both rat gastric fundus and anococcygeus muscle, suggesting a crucial role for the neurogenic NO in the pathophysiology of disturbed GI motility in cirrhosis.
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Kabil NN, Seddiek HA, Yassin NA, Gamal-Eldin MM. Effect of ghrelin on chronic liver injury and fibrogenesis in male rats: possible role of nitric oxide. Peptides 2014; 52:90-7. [PMID: 24333973 DOI: 10.1016/j.peptides.2013.11.022] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 11/25/2013] [Accepted: 11/26/2013] [Indexed: 12/11/2022]
Abstract
Recent studies have revealed that ghrelin may be an antioxidant and anti-inflammatory agent in many organs, however its role in chronic liver injury (CLI) remains unclear. The role of nitric oxide (NO) in CLI is controversial as evidence suggests that NO is either a primary mediator of liver cell injury or exhibits a protective effect against injurious stimuli. Recent evidence demonstrated that the therapeutic potential for ghrelin was through eNOS activation and increase in NO production. However, its role on NO production in the liver has not been previously investigated. The aim of this study was to investigate the role of ghrelin in treatment of CLI, and whether this action is mediated through NO. Forty male rats were divided into four groups: Group I: Control; Group II: chronic liver injury (CLI); Group III: CLI+Ghrelin; and Group IV: CLI+Ghrelin+l-NAME. Liver enzymes and tumor necrosis factor alpha (TNF-α), were measured to assess hepatocellular injury. Liver tissue collagen content, malondialdehyde (MDA), gene expression of Bax, Bcl-2, and eNOS were assessed to determine the mechanism of ghrelin action. Results showed that ghrelin decreased serum liver enzymes and TNF-α levels. Ghrelin also reduced liver tissue collagen, MDA, and Bax gene expression, and increased Bcl-2 and eNOS gene expression. The effects on TNF-α, collagen, MDA, Bax, and eNOS were partially reversed in Group IV, suggesting that ghrelin's action could be through modulation of NO levels. Therefore, ghrelin's hepatoprotective effect is partially mediated by NO release.
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Affiliation(s)
- Nashwa N Kabil
- Department of Physiology, Faculty of Pharmacy & Biotechnology, German University in Cairo, Egypt.
| | - Hanan A Seddiek
- Department of Physiology, Kasr Al Aini Faculty of Medicine, Cairo University, Egypt.
| | - Nadia A Yassin
- Department of Physiology, Faculty of Pharmacy & Biotechnology, German University in Cairo, Egypt; Department of Physiology, Kasr Al Aini Faculty of Medicine, Cairo University, Egypt.
| | - Maha M Gamal-Eldin
- Department of Physiology, Faculty of Pharmacy & Biotechnology, German University in Cairo, Egypt; Department of Physiology, Kasr Al Aini Faculty of Medicine, Cairo University, Egypt.
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Endothelial nitric oxide synthase regulates white matter changes via the BDNF/TrkB pathway after stroke in mice. PLoS One 2013; 8:e80358. [PMID: 24236179 PMCID: PMC3827451 DOI: 10.1371/journal.pone.0080358] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 10/02/2013] [Indexed: 01/19/2023] Open
Abstract
Stroke induced white matter (WM) damage is associated with neurological functional deficits, but the underlying mechanisms are not well understood. In this study, we investigate whether endothelial nitric oxide synthase (eNOS) affects WM-damage post-stroke. Adult male wild-type (WT) and eNOS knockout (eNOS(-/-)) mice were subjected to middle cerebral artery occlusion. Functional evaluation, infarct volume measurement, immunostaining and primary cortical cell culture were performed. To obtain insight into the mechanisms underlying the effects of eNOS(-/-) on WM-damage, measurement of eNOS, brain-derived neurotrophic factor (BDNF) and its receptor TrkB in vivo and in vitro were also performed. No significant differences were detected in the infarction volume, myelin density in the ipsilateral striatal WM-bundles and myelin-based protein expression in the cerebral ischemic border between WT and eNOS(-/-) mice. However, eNOS(-/-) mice showed significantly: 1) decreased functional outcome, concurrent with decreases of total axon density and phosphorylated high-molecular weight neurofilament density in the ipsilateral striatal WM-bundles. Correlation analysis showed that axon density is significantly positive correlated with neurological functional outcome; 2) decreased numbers of oligodendrocytes / oligodendrocyte progenitor cells in the ipsilateral striatum; 3) decreased synaptophysin, BDNF and TrkB expression in the ischemic border compared with WT mice after stroke (n = 12/group, p<0.05). Primary cortical cell culture confirmed that the decrease of neuronal neurite outgrowth in the neurons derived from eNOS(-/-) mice is mediated by the reduction of BDNF/TrkB (n = 6/group, p<0.05). Our data show that eNOS plays a critical role in WM-damage after stroke, and eNOS(-/-)-induced decreases in the BDNF/TrkB pathway may contribute to increased WM-damage, and thereby decrease functional outcome.
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Mapping metabolic brain activity in three models of hepatic encephalopathy. Int J Hypertens 2013; 2013:390872. [PMID: 23573412 PMCID: PMC3612461 DOI: 10.1155/2013/390872] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 02/19/2013] [Indexed: 11/17/2022] Open
Abstract
Cirrhosis is a common disease in Western countries. Liver failure, hyperammonemia, and portal hypertension are the main factors that contribute to human cirrhosis that frequently leads to a neuropsychiatric disorder known as hepatic encephalopathy (HE). In this study, we examined the differential contribution of these leading factors to the oxidative metabolism of diverse brain limbic system regions frequently involved in memory process by histochemical labelling of cytochrome oxidase (COx). We have analyzed cortical structures such as the infralimbic and prelimbic cotices, subcortical structures such as hippocampus and ventral striatum, at thalamic level like the anterodorsal, anteroventral, and mediodorsal thalamus, and, finally, the hypothalamus, where the mammillary nuclei (medial and lateral) were measured. The severest alteration is found in the model that mimics intoxication by ammonia, followed by the thioacetamide-treated group and the portal hypertension group. No changes were found at the mammillary bodies for any of the experimental groups.
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Brück J, Görg B, Bidmon HJ, Zemtsova I, Qvartskhava N, Keitel V, Kircheis G, Häussinger D. Locomotor impairment and cerebrocortical oxidative stress in portal vein ligated rats in vivo. J Hepatol 2011; 54:251-7. [PMID: 21084134 DOI: 10.1016/j.jhep.2010.06.035] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 06/08/2010] [Accepted: 06/28/2010] [Indexed: 01/09/2023]
Abstract
BACKGROUND & AIMS Oxidative/nitrosative stress plays an important role in the pathogenesis of hepatic encephalopathy and ammonia toxicity. The present study was undertaken in order to investigate the impact of portal vein ligation on cerebrocortical oxidative stress and its relation to locomotor activity. METHODS Cerebral protein tyrosine nitration, RNA oxidation, locomotor activity, and microglia activation were studied in rats that underwent portal vein ligation (PVL). RESULTS Two weeks after PVL, increased levels of protein tyrosine nitration and RNA oxidation were found in the brain. PVL rats exhibited hyperammonemia and reduced locomotor behaviour, but displayed no signs of microglia activation or upregulation of the mRNAs for interleukin-1ß and tumor necrosis factor-α. PVL also had no effect on astrocytic glutamate transporter or inducible nitric-oxide synthase expression. Only cerebral Il-6 mRNA levels were increased. Daily administration of indomethacin prevented PVL-induced protein tyrosine nitration, RNA oxidation, Il-6 mRNA increase, and the impairment of locomotor activity, but did not prevent PVL-induced hyperammonemia. CONCLUSIONS The data suggest that PVL triggers oxidative/nitrosative stress in the brain without activation of microglia and neuroinflammation. Prevention of protein tyrosine nitration and RNA oxidation by indomethacin also prevents the disturbances in locomotor activity pointing to a relevance of oxidative stress in the pathophysiology of HE.
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Affiliation(s)
- Jonathan Brück
- Clinic for Gastroenterology, Hepatology and Infectiology, Heinrich-Heine-University, Düsseldorf, Germany
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Singh S, Trigun SK. Activation of neuronal nitric oxide synthase in cerebellum of chronic hepatic encephalopathy rats is associated with up-regulation of NADPH-producing pathway. THE CEREBELLUM 2011; 9:384-97. [PMID: 20405262 DOI: 10.1007/s12311-010-0172-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cerebellum-associated functions get affected during mild hepatic encephalopathy (MHE) in patients with chronic liver failure (CLF). Involvement of nitrosative and antioxidant factors in the pathogenesis of chronic hepatic encephalopathy is an evolving concept and needs to be defined in a true CLF animal model. This article describes profiles of NADPH-dependent neuronal nitric oxide synthase (nNOS) and those of glutathione peroxidase and glutathione reductase (GR) vis-a-vis regulation of NADPH-producing pathway in the cerebellum of CLF rats induced by administration of thioacetamide (100 mg kg⁻¹ b.w., i.p.) up to 10 days and confirming MHE on Morris water maze tests. Significant increases in the expression of nNOS protein and nitric oxide (NOx) level coincided with a similar increment in NADPH-diaphorase activity in the cerebellum of CLF rats. Glutathione peroxidase and GR utilize NADPH to regenerate reduced glutathione (GSH) in the cells. Both these enzymes and GSH level were found to be static and thus suggested efficient turnover of GSH in the cerebellum of MHE rats. Relative levels of glucose-6-phosphate dehydrogenase (G6PD) vs. phosphofructokinase 2 (PFK2) determine the rate of pentose phosphate pathway (PPP) responsible to synthesize NADPH. The cerebellum of CLF rats showed overactivation of G6PD with a significant decline in the expression of PFK2 and thus suggested activation of PPP in the cerebellum during MHE. It is concluded that concordant activations of PPP and nNOS in cerebellum of MHE rats could be associated with the implication of NOx in the pathogenesis of MHE.
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Affiliation(s)
- Santosh Singh
- Biochemistry and Molecular Biology Laboratory, Centre of Advanced Studies in Zoology, Banaras Hindu University, Varanasi 221005, India
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Skowrońska M, Zielińska M, Albrecht J. Stimulation of natriuretic peptide receptor C attenuates accumulation of reactive oxygen species and nitric oxide synthesis in ammonia-treated astrocytes. J Neurochem 2010; 115:1068-76. [PMID: 20854429 DOI: 10.1111/j.1471-4159.2010.07008.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Oxidative and nitrosative stress contribute to ammonia-induced astrocytic dysfunction in hepatic encephalopathy. Treatment of cultured astrocytes with 5 mmol/L ammonium chloride ('ammonia') increased the production of reactive oxygen species (ROS), including the toxic NADPH oxidase reaction product, •O(2)(-). Atrial natriuretic peptide (ANP), natriuretic peptide C and a selective natriuretic peptide receptor (NPR)-C ligand, cANP((4-23),) each decreased the total ROS content both in control cells and cells treated with ammonia. However, attenuation of •O(2)(-) accumulation by ANP and cANP((4-23),) was observed in ammonia-treated cells only and the effect of cANP((4-23)) was decreased when the NADPH oxidase-regulatory protein G(iα-2) was blocked with a specific anti-G(iα-2) antibody. Although in contrast to ANP, cANP((4-23)) did not elevate the cGMP content in control astrocytes, it decreased cAMP content and reduced the expression of G(iα-2), the NADPH oxidase-regulatory protein. The results show the presence of functional NPR-C in astrocytes, activation of which (i) attenuates basal ROS production, and (ii) prevents excessive accumulation of the toxic ROS species, •O(2)(-) by ammonia. Ammonia, ANP and cANP((4-23)) added separately, each stimulated formation of NO(x) (nitrates + nitrites) which was associated with up-regulation of the activity [cANP((4-23))] or/and expression (ammonia) of the endothelial isoform of nitric oxide synthase. However, the ammonia-induced increase of NO(x) was not augmented by co-addition of ANP, and was reduced to the control level by co-addition of cANP((4-23)) , indicating that activation of NPR-C may also reduce nitrosative stress. Future hepatic encephalopathy therapy might include the use of cANP((4-23)) or other NPR-C agonists to control oxidative/nitrosative stress induced by ammonia.
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Affiliation(s)
- Marta Skowrońska
- Department of Neurotoxicology, Mossakowski Medical Research Center, Polish Academy of Sciences, Warsaw, Poland
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Görg B, Qvartskhava N, Bidmon HJ, Palomero-Gallagher N, Kircheis G, Zilles K, Häussinger D. Oxidative stress markers in the brain of patients with cirrhosis and hepatic encephalopathy. Hepatology 2010; 52:256-65. [PMID: 20583283 PMCID: PMC3395472 DOI: 10.1002/hep.23656] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
UNLABELLED Cell culture studies and animal models point to an important role of oxidative/nitrosative stress in the pathogenesis of cerebral ammonia toxicity. However, it is unknown whether oxidative/nitrosative stress in the brain is also characteristic of hepatic encephalopathy (HE) in humans. We therefore analyzed post mortem cortical brain tissue samples from patients with cirrhosis dying with or without HE in comparison with brains from patients without liver disease. Significantly elevated levels of protein tyrosine-nitrated proteins, heat shock protein-27, and 8-hydroxyguanosine as a marker for RNA oxidation were found in the cerebral cortex of HE patients, but not of patients with cirrhosis but without HE. Glutamine synthetase (GS) activity was significantly decreased, whereas GS protein expression was not significantly affected. Protein expression of the glutamate/aspartate cotransporter was up-regulated in HE, whereas protein expression of neuronal and inducible nitric oxide synthases, manganese-dependent and copper/zinc-dependent superoxide dismutase, and glial glutamate transporter-1 were not significantly increased. CONCLUSION These data indicate that HE in patients with cirrhosis is associated with oxidative/nitrosative stress, protein tyrosine nitration, and RNA oxidation, suggesting a role of oxidative stress in the pathogenesis of HE in patients with cirrhosis.
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Affiliation(s)
- Boris Görg
- Clinic for Gastroenterology, Hepatology, and Infectiology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Natalia Qvartskhava
- Clinic for Gastroenterology, Hepatology, and Infectiology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Hans-Jürgen Bidmon
- C&O Vogt Institute for Brain Research, Heinrich-Heine-University, Düsseldorf, Germany
| | | | - Gerald Kircheis
- Clinic for Gastroenterology, Hepatology, and Infectiology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Karl Zilles
- C&O Vogt Institute for Brain Research, Heinrich-Heine-University, Düsseldorf, Germany,Institute of Neurosciences and Medicine (INM-2), Jülich Research Centre, Jülich, Germany
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology, and Infectiology, Heinrich-Heine-University, Düsseldorf, Germany
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Blanco S, Molina FJ, Castro L, Del Moral ML, Hernandez R, Jimenez A, Rus A, Martinez-Lara E, Siles E, Peinado MA. Study of the nitric oxide system in the rat cerebellum during aging. BMC Neurosci 2010; 11:78. [PMID: 20576087 PMCID: PMC2905430 DOI: 10.1186/1471-2202-11-78] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Accepted: 06/24/2010] [Indexed: 11/30/2022] Open
Abstract
Background The cerebellum is the neural structure with the highest levels of nitric oxide, a neurotransmitter that has been proposed to play a key role in the brain aging, although knowledge concerning its contribution to cerebellar senescence is still unclear, due mainly to absence of integrative studies that jointly evaluate the main factors involved in its cell production and function. Consequently, in the present study, we investigate the expression, location, and activity of nitric oxide synthase isoenzymes; the protein nitration; and the production of nitric oxide in the cerebellum of adult and old rats. Results Our results show no variation in the expression of nitric oxide synthase isoforms with aging, although, we have detected some changes in the cellular distribution pattern of the inducible isoform particularly in the cerebellar nuclei. There is also an increase in nitric oxide synthase activity, as well as greater protein-nitration levels, and maintenance of nitrogen oxides (NOx) levels in the senescent cerebellum. Conclusions The nitric oxide/nitric oxide syntahses system suffers from a number of changes, mainly in the inducible nitric oxide synthase distribution and in overall nitric oxide synthases activity in the senescent cerebellum, which result in an increase of the protein nitration. These changes might be related to the oxidative damage detected with aging in the cerebellum.
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Affiliation(s)
- Santos Blanco
- Department of Experimental Biology, University of Jaen, Campus Las Lagunillas s/n, 23071, Jaén, Spain
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Bemeur C, Desjardins P, Butterworth RF. Evidence for oxidative/nitrosative stress in the pathogenesis of hepatic encephalopathy. Metab Brain Dis 2010; 25:3-9. [PMID: 20195724 DOI: 10.1007/s11011-010-9177-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Accepted: 09/22/2009] [Indexed: 12/11/2022]
Abstract
Hepatic encephalopathy (HE) is a serious complication of liver failure. HE manifests as a series of neuropsychiatric and neuromuscular symptoms including personality changes, sleep abnormalities, asterixis and muscle rigidity progressing through stupor to coma. The pathophysiologic basis of HE remains unclear. There is general agreement that ammonia plays a key role. In recent years, it has been suggested that oxidative/nitrosative stress constitutes part of the pathophysiologic cascade in HE. Direct evidence for oxidative/nitrosative stress in the pathogenesis of HE has been demonstrated in experimental animal models of acute or chronic liver failure. However, evidence from studies in HE patients is limited. This review summarizes this evidence for a role of oxidative/nitrosative stress in relation to ammonia toxicity and to the pathogenesis of HE.
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Affiliation(s)
- Chantal Bemeur
- Neuroscience Research Unit, Hôpital Saint-Luc (CHUM) University of Montreal, Montreal, QC, Canada
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Alterations in expression of genes coding for proteins of the neurovascular unit in ischemic liver failure. Neurochem Int 2009; 55:119-23. [DOI: 10.1016/j.neuint.2009.01.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 01/26/2009] [Accepted: 01/27/2009] [Indexed: 01/20/2023]
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Basal and learning task-related brain oxidative metabolism in cirrhotic rats. Brain Res Bull 2008; 78:195-201. [PMID: 19015011 DOI: 10.1016/j.brainresbull.2008.10.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Revised: 09/19/2008] [Accepted: 10/17/2008] [Indexed: 11/24/2022]
Abstract
Hepatic encephalopathy is a neurological complication observed in patients with liver disease. Subjects with hepatic encephalopathy can develop memory alterations. In order to investigate brain oxidative metabolism in an animal model of chronic cirrhosis and its modification after spatial working memory task, we determined the neural metabolic activity of several brain limbic system regions by cytochrome oxidase (COx) histochemistry and assessed the spatial working memory in the Morris water maze of rats with cirrhosis by administration of thioacetamide. This COx histochemistry was done in cirrhotic and control rats under basal conditions and after the spatial working memory task. The histochemical results showed differences in basal COx activity between control and cirrhotic rats in hippocampal and thalamic regions. In cirrhotic rats basal COx activity was increased in the CA1 and CA3 areas of the hippocampus and reduced in the anterodorsal and anteroventral thalamic nuclei. We found impaired spatial working memory in animals with cirrhosis. These animals showed absence of metabolic activation of the CA3 hippocampal subfield and the lateral mammillary nucleus and disturbance of COx activity in the medial mammillary nucleus and the anteroventral thalamus. These findings suggest that cirrhotic rats show spatial working memory deficits that could be related to the alteration of metabolic activity of neural regions thought to be involved in the processing of spatial memories.
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Blanco S, Castro L, Hernández R, Del Moral ML, Pedrosa JA, Martínez-Lara E, Siles E, Peinado MA. Age modulates the nitric oxide system response in the ischemic cerebellum. Brain Res 2007; 1157:66-73. [PMID: 17544383 DOI: 10.1016/j.brainres.2007.01.141] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Revised: 01/19/2007] [Accepted: 01/23/2007] [Indexed: 10/23/2022]
Abstract
To determine whether age influences the nitric oxide system response to ischemia in the cerebellum, we have analyzed the levels of nitrogen oxides (NOx) and the expression of the different nitric oxide synthase isoforms (NOS) in mature adult (4-5 months old) and aged rats (24-27 months old) subjected to a transient global ischemia/reperfusion (I/R) model. We also analyzed the nitrated proteins and the glial fibrillary acidic protein (GFAP) expression. NOx concentration in adult rats, which more than doubled the values found in the aged rats, decreased after the ischemia and reperfusion. However, in the aged animals, these NOx levels did not significantly change after I/R. Constitutive isoforms were first down-regulated in the ischemic period, in both adult and aged animals. However, after 6 h of reperfusion, these isoforms were up-regulated, but only in aged rats. After I/R, iNOS was up-regulated in adults but down-regulated in the aged rats. Hence, after an episode of transient global ischemia and reperfusion, the aged cerebellum maintains a balanced NO production, silencing the iNOS isoform and inducing a weak expression of nNOS and eNOS; this allows NO physiological functions while avoiding possible undesirable effects such as the nitrative damage or astrocyte activation.
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Affiliation(s)
- Santos Blanco
- Department of Experimental Biology, University of Jaén, Paraje Las Lagunillas s/n, 23071, Jaén, Spain
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Ghasemi M, Sadeghipour H, Shafaroodi H, Nezami BG, Gholipour T, Hajrasouliha AR, Tavakoli S, Nobakht M, Moore KP, Mani AR, Dehpour AR. Role of the nitric oxide pathway and the endocannabinoid system in neurogenic relaxation of corpus cavernosum from biliary cirrhotic rats. Br J Pharmacol 2007; 151:591-601. [PMID: 17486141 PMCID: PMC2013996 DOI: 10.1038/sj.bjp.0707279] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE Relaxation of corpus cavernosum, which is mediated by nitric oxide (NO) released from non-adrenergic non-cholinergic (NANC) neurotransmission, is critical for inducing penile erection and can be affected by many pathophysiological conditions. However, the peripheral effect of liver cirrhosis on erectile function is as yet unknown. The aim of the present study was to investigate the effect of biliary cirrhosis on NANC-mediated relaxation of rat corpus cavernosum and the possible roles of endocannabinoid and nitric oxide systems in this model. EXPERIMENTAL APPROACH Cirrhosis was induced by bile duct ligation. Controls underwent sham operation. Four weeks later, strips of corpus cavernosum were mounted in a standard organ bath and NANC-mediated relaxations were obtained by applying electrical field stimulation. KEY RESULTS The NANC-mediated relaxation was enhanced in corporal strips from cirrhotic animals. Anandamide potentiated the relaxations in both groups. Either AM251 (CB(1) antagonist) or capsazepine (vanilloid VR(1) antagonist), but not AM630 (CB(2) antagonist), prevented the enhanced relaxations of cirrhotic strips. Either the non-selective NOS inhibitor L-NAME or the selective neuronal NOS inhibitor L-NPA inhibited relaxations in both groups, but cirrhotic groups were more resistant to the inhibitory effects of these agents. Relaxations to sodium nitroprusside (NO donor) were similar in tissues from the two groups. CONCLUSIONS AND IMPLICATIONS Cirrhosis potentiates the neurogenic relaxation of rat corpus cavernosum probably via the NO pathway and involving cannabinoid CB(1) and vanilloid VR(1) receptors.
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Affiliation(s)
- M Ghasemi
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
- The UCL Institute of Hepatology, Department of Medicine, Royal Free and University College Medical School, UCL London, UK
| | - H Sadeghipour
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
| | - H Shafaroodi
- Department of Pharmacology, Tehran Medical Unit, Islamic Azad University of Medical Sciences Tehran, Iran
| | - B G Nezami
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
| | - T Gholipour
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
| | - A R Hajrasouliha
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
| | - S Tavakoli
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
| | - M Nobakht
- Department of Histology, Medical School, Iran University of Medical Sciences Tehran, Iran
| | - K P Moore
- The UCL Institute of Hepatology, Department of Medicine, Royal Free and University College Medical School, UCL London, UK
| | - A R Mani
- The UCL Institute of Hepatology, Department of Medicine, Royal Free and University College Medical School, UCL London, UK
| | - A R Dehpour
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
- Author for correspondence:
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Palumbo ML, Fosser NS, Rios H, Zorrilla Zubilete MA, Guelman LR, Cremaschi GA, Genaro AM. Loss of hippocampal neuronal nitric oxide synthase contributes to the stress-related deficit in learning and memory. J Neurochem 2007; 102:261-74. [PMID: 17419805 DOI: 10.1111/j.1471-4159.2007.04528.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nitric oxide (NO) has been involved in many pathophysiological brain processes. However, the exact role of NO in the cognitive deficit associated to chronic stress exposure has not been elucidated. In this study, we investigated the participation of hippocampal NO production and their regulation by protein kinase C (PKC) in the memory impairment induced in mice subjected to chronic mild stress model (CMS). CMS mice showed a poor learning performance in both open field and passive avoidance inhibitory task respect to control mice. Histological studies showed a morphological alteration in the hippocampus of CMS mice. On the other hand, chronic stress induced a diminished NO production by neuronal nitric oxide synthase (nNOS) correlated with an increment in gamma and zeta PKC isoenzymes. Partial restoration of nNOS activity was obtained after PKC activity blockade. NO production by inducible nitric oxide synthase isoform was not detected. The magnitude of oxidative stress, evaluated by reactive oxygen species production, after excitotoxic levels of NMDA was increased in hippocampus of CMS mice. Moreover, ROS formation was higher in the presence of nNOS inhibitor in both control and CMS mice. Finally, treatment of mice with nNOS inhibitors results in behavioural alterations similar to those observed in CMS animals. These findings suggest a novel role for nNOS showing protective activity against insults that trigger tissue toxicity leading to memory impairments.
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Affiliation(s)
- María Laura Palumbo
- CEFYBO-CONICET and 1a. Cát. de Farmacología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
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18
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Zorrilla Zubilete MA, Ríos H, Silberman DM, Guelman LR, Ricatti MJ, Genaro AM, Zieher LM. Altered nitric oxide synthase and PKC activities in cerebellum of gamma-irradiated neonatal rats. Brain Res 2005; 1051:8-16. [PMID: 15993387 DOI: 10.1016/j.brainres.2005.05.046] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2004] [Revised: 05/12/2005] [Accepted: 05/14/2005] [Indexed: 11/24/2022]
Abstract
In this study, we show that one single dose of gamma-irradiation at birth induces an inhibition of the cerebellar calcium dependent nitric oxide synthase (NOS) activity, probably correlated to the motor abnormalities and the disarrangement in the cerebellar cytoarchitecture observed in adult rats. This decrease in calcium dependent NOS activity could be associated with an increased protein kinase C (PKC) activity. PKC inhibition partially restores calcium dependent NOS activity, indicating that PKC activity could be negatively modulating the catalytic activity of calcium dependent NOS. These findings suggest that a decrease in nitric oxide (NO) production and the related increase in PKC activity could be intracellular events that participate in the onset of motor and cerebellar abnormalities induced by postnatal gamma-irradiation at early stages of life.
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Affiliation(s)
- María A Zorrilla Zubilete
- 1a Cátedra de Farmacología, Facultad de Medicina, Universidad de Buenos Aires (UBA), 2155 Paraguay St. Piso 15, (1121) Ciudad de Buenos Aires, Argentina.
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