title: [Expression and function of vascular endothelial growth factor and angiopoietins in rat brain after cerebral ischemia].
abstract: OBJECTIVE
  To examine the temporal and spatial expression of vascular endothelial growth factor (VEGF) and angiopoietins (Ang) in rat brain after cerebral ischemia, and to elucidate the roles they played in angiogenesis and vascular permeability.
  
  
  METHODS
  Rats were subjected to either middle cerebral artery occlusion (MCAO) or sham operation. Reverse transcriptase-polymerase chain reaction, Western blotting, and immunohistochemistry were used to detect the expression of VEGF, Ang-1 and Ang-2 at different time points after ischemia. CD31 was used to label endothelial cells after MCAO. Vascular permeability was determined by Evans blue.
  
  
  RESULTS
  VEGF was markedly increased at 2 h, had an initial peak at 12 h (0.7249 ± 0.1933, P < 0.01), and a second peak at 7 days (0.5264 ± 0.1519, P < 0.01). Ang-2 mRNA and protein significantly increased after MCAO, both of them peaked at 12 h (0.6747 ± 0.2416, P < 0.01; 1.1197 ± 0.1780, P < 0.01). In contrast, Ang-1 mRNA and protein gradually decreased after MCAO, respectively reaching a minimum at 3 d (0.3220 ± 0.1427, P < 0.01) and 1 d (0.1298 ± 0.0293, P < 0.01). Changes in the expression of these factors correlated with the progress of angiogenesis and vascular permeability. Evans blue test revealed that the vascular permeability gradually increased, and peaked at day 1 after ischemia [(6.219 ± 0.887) µg/g, P < 0.01].
  
  
  CONCLUSIONS
  Dynamic temporal changes in VEGF, Ang-1 and Ang-2 expression stimulate the cerebral angiogenesis after focal cerebral ischemia.
authors.affiliation: Department of Pathology, Harbin Medical University, Harbin, China.
authors.forename: Li-kun
authors.initials: LK
authors.lastname: Zan
authors.forename: Yue-jia
authors.initials: YJ
authors.lastname: Song
authors.forename: Guo-xin
authors.initials: GX
authors.lastname: Teng
authors.forename: Heng
authors.initials: H
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Jia
authors.forename: Min
authors.initials: M
authors.lastname: Zhou
authors.forename: Yu-lan
authors.initials: YL
authors.lastname: Sun
authors.forename: Ji-ping
authors.initials: JP
authors.lastname: Qi
mesh_terms: D042683:Angiopoietin-1 / Q000235:genetics / Q000378:metabolism*; D042702:Angiopoietin-2 / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D002199:Capillary Permeability; D007150:Immunohistochemistry; D020244:Infarction, Middle Cerebral Artery / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D018919:Neovascularization, Physiologic; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
chemical_list: D042683:Angiopoietin-1; D042702:Angiopoietin-2; C467629:Angpt1 protein, rat; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat