Linked Life Data

15185294

Source:http://linkedlifedata.com/resource/pubmed/id/15185294

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2004-6-8
pubmed:abstractText
We investigated the effects of nitric oxide (NO) on hepatocellular killing after simulated ischemia/reperfusion and characterized signaling factors triggering cytoprotection by NO. Cultured rat hepatocytes were incubated in anoxic Krebs-Ringer-HEPES buffer at pH 6.2 for 4 hours and reoxygenated at pH 7.4 for 2 hours. During reoxygenation, some hepatocytes were exposed to combinations of NO donors (S-nitroso-N-acetylpenicillamine [SNAP] and others), a cGMP analogue (8-bromoguanosine-3,5-cGMP [8-Br-cGMP]), and a cGMP-dependent protein kinase inhibitor (KT5823). Cell viability was determined by way of propidium iodide fluorometry. Inner membrane permeabilization and mitochondrial depolarization were monitored by confocal microscopy. SNAP, but not oxidized SNAP, increased cGMP during reperfusion and decreased cell killing. Other NO donors and 8-Br-cGMP also prevented cell killing. Both guanylyl cyclase and cGMP-dependent kinase inhibition blocked the cytoprotection of NO. However, 5-hydroxydecanoate and diazoxide- mitochondrial K(ATP) channel modulators-did not affect NO-dependent cytoprotection or reperfusion injury. During reoxygenation, confocal microscopy showed mitochondrial repolarization, followed by depolarization, inner membrane permeabilization, and cell death. In the presence of either SNAP or 8-Br-cGMP, mitochondrial repolarization was sustained after reperfusion preventing inner membrane permeabilization and cell death. In isolated rat liver mitochondria, a cGMP analogue in the presence of a cytosolic extract and adenosine triphosphate blocked the Ca(2+)-induced mitochondrial permeability transition (MPT), an effect that was reversed by KT5823. In conclusion, NO prevents MPT-dependent necrotic killing of ischemic hepatocytes after reperfusion through a guanylyl cyclase and cGMP-dependent kinase signaling pathway, events that may represent the target of NO cytoprotection in preconditioning.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0270-9139
pubmed:author
pubmed:issnType
Print
pubmed:volume
39
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1533-43
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Nitric oxide protects rat hepatocytes against reperfusion injury mediated by the mitochondrial permeability transition.
pubmed:affiliation
Department of Cell and Developmental Biology, School of Medicine, University of North Carolina, Chapel Hill, NC, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.