Expression of vascular endothelial growth factor mRNA following transient forebrain ischemia in rats.
Using a reproducible two-vessel occlusion model for forebrain ischemia in rats, we investigated the temporal and spatial changes of vascular endothelial growth factor (VEGF) expression after transient forebrain ischemia with Northern blot analysis and in situ hybridization. Northern blot analysis revealed that VEGF mRNA of the hippocampus was increased from 12 h after reperfusion, with a peak at 1 day. In situ hybridization and double labeling for VEGF mRNA and glial fibrillary acidic protein showed a transient induction of VEGF mRNA in the neurons of the hippocampus from 12 h of reperfusion with a peak at 1 day, and in the astrocytes of the hippocampus, caudoputamen, thalamus and cortical regions at 1 day. After 3 days, no more VEGF signal was detected. Our results demonstrate that astrocytes and neurons each upregulate VEGF mRNA in different temporal and spatial patterns after transient forebrain ischemia in the rat, and these patterns appear to be different from those in transient focal cerebral ischemia.
D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D015152:Blotting, Northern; D001921:Brain / Q000166:cytology / Q000378:metabolism; D016228:Endothelial Growth Factors / Q000235:genetics*; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism; D017403:In Situ Hybridization; D002546:Ischemic Attack, Transient / Q000378:metabolism*; D008222:Lymphokines / Q000235:genetics*; D008297:Male; D009474:Neurons / Q000378:metabolism; D016548:Prosencephalon / Q000098:blood supply*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014018:Tissue Distribution / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors