title: [Estrogen decreases vascular damage induced by chronic hypoperfusion through upregulating VEGF expression].
abstract: OBJECTIVE
  To evaluate the effect of physiological dose 17-β-estrodiol (E2) replacement therapy on vascular dementia caused by cerebral chronic hypoperfusion.
  
  
  METHODS
  The rats with bilateral common carotid artery occlusion (BCCAO) received E2 treatment starting from 3 days or 3 months after the operation. IgG leakage into the brain parenchyma and the changes of microvascular ultrastructure following BCCAO were examined using immunohistochemistry and electron microscopy, respectively; Western blotting was used to detect the expression of vascular endothelial growth factor (VEGF) protein.
  
  
  RESULTS
  Compared with the sham-operated groups, the rats at 3 days and 3 months after BCCAO showed extensive vascular damages surrounded by IgG immunoreactivity in both the cortical and hippocampal CA1 regions. Stronger IgG immunoreactivity in the hippocampal CA1 region was observed at 3 days after BCCAO than at 3 months, but no significant IgG leakage was found in rats with continuous E2 treatment. Electron microscopy revealed severe edema around the blood vessels, mild vascular dilation, and endothelial cell damages at both 3 days and 3 months after BCCAO. E2 treatment markedly reduced the microvascular ultrastructural damages. Western blot analysis showed a significant increase in VEGF expression in the CA1 region at 6 h and 1 day after BCCAO followed by an obvious reduction till reaching the lowest level at 3 days; VEGF expression remained low even at 3 months after BCCAO and was significantly increased by E2 treatment.
  
  
  CONCLUSIONS
  Vascular structural damage occurs early after BCCAO and can last for 3 months. E2 replacement therapy at physiological doses can reduce the incidence of BCCAO-induced vascular dementia by up-regulating VEGF expression.
authors.affiliation: Department of Anesthesia, Shunde First People's Hospital Affiliated to Southern Medical University, Foshan 528300, China.E-mail: ssss047@163.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Tang
authors.forename: Wenli
authors.initials: W
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu
authors.forename: Xi
authors.initials: X
authors.lastname: Zhang
authors.forename: Ruimin
authors.initials: R
authors.lastname: Wang
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000473:pathology; D056547:CA1 Region, Hippocampal / Q000378:metabolism / Q000473:pathology; D015140:Dementia, Vascular / Q000188:drug therapy* / Q000378:metabolism; D004195:Disease Models, Animal; D004958:Estradiol / Q000494:pharmacology*; D051381:Rats; D015533:Transcriptional Activation; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; D004958:Estradiol