Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2005-8-24
pubmed:abstractText
Hypothermia is effective in preventing ischemic damage. A caspase-dependent apoptotic pathway is involved in ischemic damage, but how hypothermia inhibits this pathway after global cerebral ischemia has not been well explored. It was determined whether hypothermia protects the brain by altering cytochrome c release and caspase activity. Cerebral ischemia was produced by two-vessel occlusion plus hypotension for 10 mins. Body temperature in hypothermic animals was reduced to 33 degrees C before ischemia onset and maintained for 3 h after reperfusion. Western blots of subcellular fractions revealed biphasic cytosolic cytochrome c release, with an initial peak at about 5 h after ischemia, which decreased at 12 to 24 h, and a second, larger peak at 48 h. Caspase-3 and -9 activity increased at 12 and 24 h. A caspase inhibitor, Z-DEVD-FMK, administered 5 and 24 h after ischemia onset, protected hippocampal CA1 neurons from injury and blocked the second cytochrome c peak, suggesting that caspases mediate this second phase. Hypothermia (33 degrees C), which prevented CA1 injury, did not inhibit cytochrome c release at 5 h, but reduced cytochrome c release at 48 h. Caspase-3 and -9 activity was markedly attenuated by hypothermia at 12 and 24 h. Thus, biphasic cytochrome c release occurs after transient global ischemia and mild hypothermia protects against ischemic damage by blocking the second phase of cytochrome c release, possibly by blocking caspase activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0271-678X
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1119-29
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:15789032-Animals, pubmed-meshheading:15789032-Apoptosis, pubmed-meshheading:15789032-Blotting, Western, pubmed-meshheading:15789032-Brain, pubmed-meshheading:15789032-Caspase 3, pubmed-meshheading:15789032-Caspase 9, pubmed-meshheading:15789032-Caspases, pubmed-meshheading:15789032-Cytochromes c, pubmed-meshheading:15789032-Enzyme Inhibitors, pubmed-meshheading:15789032-Fluorescent Antibody Technique, Indirect, pubmed-meshheading:15789032-Hypothermia, Induced, pubmed-meshheading:15789032-Ischemic Attack, Transient, pubmed-meshheading:15789032-Male, pubmed-meshheading:15789032-Neurons, pubmed-meshheading:15789032-Rats, pubmed-meshheading:15789032-Rats, Sprague-Dawley, pubmed-meshheading:15789032-Spectrometry, Fluorescence, pubmed-meshheading:15789032-Subcellular Fractions
pubmed:year
2005
pubmed:articleTitle
Biphasic cytochrome c release after transient global ischemia and its inhibition by hypothermia.
pubmed:affiliation
Department of Neurosurgery, Stanford University, Stanford, California 94305-5327, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, N.I.H., Extramural