Free radicals are involved in continuous activation of nonreceptor tyrosine protein kinase c-Src after ischemia/reperfusion in rat hippocampus.
NMDA receptor-mediated calcium over-loading and the following free radical generation play essential roles in cerebral ischemia lesion, leading to neuronal cell apoptosis or necrosis through complicated intracellular signaling cascades. Here we evaluated the effects of NMDA receptor antagonist (ketamine) and antioxidant (N-acetylcysteine) on ischemia- and reperfusion-induced activation of tyrosine kinase c-Src. The in vitro kinase assay showed that the ischemia-induced rapid activation of c-Src reached its peak at 5 min, and the reperfusion-induced continuous activation of c-Src reached another peak at 6 h reperfusion after 15 min ischemia (4.2 and 3.0 fold vs. sham control, respectively). Ketamine might suppress both peaks described above, but N-acetylcysteine, a free radical scavenger, was only able to partly reduce the peak activation elicited by 6 h reperfusion. These results suggest that free radical production is involved in NMDA receptor-mediated continuous activation of c-Src during ischemia/reperfusion but not that during ischemia.
Guo
Jun
J
Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, 84 West Huai-hai Road, Xuzhou, Jiangsu 221002, PR China.
Meng
Fanjie
F
Zhang
Guangyi
G
Zhang
Quanguang
Q
D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D002545:Brain Ischemia / Q000201:enzymology*; D000081247:CSK Tyrosine-Protein Kinase; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology; D005609:Free Radicals / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D015151:Immunoblotting / Q000379:methods; D007649:Ketamine / Q000494:pharmacology; D008297:Male; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015424:Reperfusion; D013460:Sulfur Isotopes / Q000378:metabolism; D013997:Time Factors; D019061:src-Family Kinases
D018691:Excitatory Amino Acid Antagonists; D016166:Free Radical Scavengers; D005609:Free Radicals; D013460:Sulfur Isotopes; D007649:Ketamine; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; D010751:Phosphopyruvate Hydratase; D000111:Acetylcysteine