Extracellular signal-regulated kinase 1/2 activation in hippocampus after cerebral ischemia may not interfere with postischemic cell death.
To investigate the effect of the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) on cerebral ischemic injury, temporospatial alterations of active (diphosphorylated) ERK1/2 immunoreactivity in hippocampus was examined. Western blot showed that diphosphorylated ERK1/2 were decreased at 10 min of cerebral ischemia but increased rapidly (within 2 min) and transiently (within 4 h) during reperfusion. Immunohistochemistry showed that little diphosphorylated ERK1/2 immunoreactivity was seen in CA1 pyramidal cell bodies after ischemia, while strong immunoreactivity were seen in neuronal bodies in CA3/DG and in fiber systems in both CA1 and CA3 regions. Cerebral ventricular infusion of PD98059, a specific inhibitor of ERK kinase, completely prevented ERK1/2 activation after ischemia but had no effect on the survival of pyramidal cells in CA1 subfield. The results suggest that ERK1/2 activation in hippocampus after brain ischemia may not interfere with the postischemic cell death in CA1 region.
Gu
Z
Z
Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, 221002, Xuzhou, PR China.
Jiang
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Q
Zhang
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G
D000818:Animals; D002545:Brain Ischemia / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D016923:Cell Death / Q000187:drug effects / Q000502:physiology*; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000201:enzymology* / Q000503:physiopathology; D007150:Immunohistochemistry; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000187:drug effects / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism*; D009410:Nerve Degeneration / Q000201:enzymology / Q000378:metabolism / Q000503:physiopathology; D010766:Phosphorylation / Q000187:drug effects; D017966:Pyramidal Cells / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley
D004791:Enzyme Inhibitors; D005419:Flavonoids; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one