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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2010-10-22
pubmed:abstractText
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(i?-2) was blocked with a specific anti-G(i?-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(i?-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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1471-4159
pubmed:author
pubmed:copyrightInfo
© 2010 The Authors. Journal of Neurochemistry © 2010 International Society for Neurochemistry.
pubmed:issnType
Electronic
pubmed:volume
115
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1068-76
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Stimulation of natriuretic peptide receptor C attenuates accumulation of reactive oxygen species and nitric oxide synthesis in ammonia-treated astrocytes.
pubmed:affiliation
Department of Neurotoxicology, Mossakowski Medical Research Center, Polish Academy of Sciences, Warsaw, Poland.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't