Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2001-5-2
pubmed:abstractText
Previous histopathologic results have suggested that one mechanism whereby hyperglycemia (HG) leads to exaggerated ischemic damage involves fragmentation of DNA. DNA fragmentation in normoglycemia (NG) and HG rats subjected to 30 minutes of forebrain ischemia was studied by terminal deoxynucleotidyl transferase mediated DNA nick-labeling (TUNEL) staining, by pulse-field gel electrophoresis (PFGE), and by ligation-mediated polymerase chain reaction (LM-PCR). High molecular weight DNA fragments were detected by PFGE, whereas low molecular weight DNA fragments were detected using LM-PCR techniques. The LM-PCR procedure was performed on DNA from test samples with blunt (without Klenow polymerase) and 3'-recessed ends (with Klenow polymerase). In addition, cytochrome c release and caspase-3 activation were studied by immunocytochemistry. Results show that HG causes cytochrome c release, activates caspase-3, and exacerbates DNA fragments induced by ischemia. Thus, in HG rats, but not in control or NGs, TUNEL-stained cells were found in the cingulate cortex, neocortex, thalamus, and dorsolateral crest of the striatum, where neuronal death was observed by conventional histopathology, and where both cytosolic cytochrome c and active caspase-3 were detected by confocal microscopy. In the neocortex, both blunt-ended and stagger-ended fragments were detected in HG, but not in NG rats. Electron microscopy (EM) analysis was performed in the cingulate cortex, where numerous TUNEL-positive neurons were observed. Although DNA fragmentation was detected by TUNEL staining and electrophoresis techniques, EM analysis failed to indicate apoptotic cell death. It is concluded that HG triggers a cell death pathway and exacerbates DNA fragmentation induced by ischemia.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0271-678X
pubmed:author
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
568-76
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11333367-Animals, pubmed-meshheading:11333367-Apoptosis, pubmed-meshheading:11333367-Caspase 3, pubmed-meshheading:11333367-Caspases, pubmed-meshheading:11333367-Corpus Striatum, pubmed-meshheading:11333367-Cytochrome c Group, pubmed-meshheading:11333367-DNA Fragmentation, pubmed-meshheading:11333367-Dentate Gyrus, pubmed-meshheading:11333367-Enzyme Activation, pubmed-meshheading:11333367-Hippocampus, pubmed-meshheading:11333367-Hyperglycemia, pubmed-meshheading:11333367-In Situ Nick-End Labeling, pubmed-meshheading:11333367-Ischemic Attack, Transient, pubmed-meshheading:11333367-Male, pubmed-meshheading:11333367-Microscopy, Electron, pubmed-meshheading:11333367-Neocortex, pubmed-meshheading:11333367-Neurons, pubmed-meshheading:11333367-Rats, pubmed-meshheading:11333367-Rats, Wistar, pubmed-meshheading:11333367-Thalamus
pubmed:year
2001
pubmed:articleTitle
Hyperglycemia enhances DNA fragmentation after transient cerebral ischemia.
pubmed:affiliation
Center for Biomedical Research, The Queen's Medical Center, John A. Burns School of Medicine, University of Hawaii, Honolulu, 98613, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't