title: Angiopoietin-1 and Angiopoietin-2 Expression Imbalance Influence in Early Period After Subarachnoid Hemorrhage.
abstract: OBJECTIVE
  Microvascular endothelial integrity is important for maintaining the blood-brain barrier (BBB). However, subarachnoid hemorrhage (SAH) disrupts this integrity, making the BBB dysfunctional-an important pathophysiological change after SAH. Angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) regulate microvascular permeability by balancing each other's expression.
  
  
  METHODS
  This study investigated the dynamics of Ang-1 and Ang-2 expression after SAH and the protective effect of Ang-1 on BBB functioning using an endovascular puncture model of rat SAH. The Ang-1 and Ang-2 expression in brain tissue was determined by immunohistochemistry. In addition, Western blotting was used to estimate Ang-1 and Ang-2 concentration and to compare them at 6-72 hours post-SAH cortex and hippocampus. Evans blue viability assay was used to evaluate BBB permeability, and neurological testing was implemented to evaluate neurological impairment during SAH.
  
  
  RESULTS
  It was found that following SAH, Ang-1 expression decreases and Ang-2 expression increases in the cortex, hippocampus, and microvessels. The Ang-1/Ang-2 ratio decreased as quickly as 6 hours after SAH and reached its lowest 1 day after SAH. Finally, it was found that exogenous Ang-1 reduces SAH-associated BBB leakage and improves neurological function in post-SAH rats.
  
  
  CONCLUSIONS
  Our findings suggest that the equilibrium between Ang-1 and Ang-2 is broken in a period shortly after SAH, and the treatment of exogenous Ang-1 injection alleviates neurological dysfunctions through decreasing BBB destruction.
authors.affiliation: Department of Neurosurgery, The First Affiliated Hospital of Huzhou Teachers College, Huzhou, China.
authors.forename: Hua
authors.identifier: 0000-0003-0740-9522
authors.initials: H
authors.lastname: Gu
authors.affiliation: Department of Neurosurgery, The First Affiliated Hospital of Huzhou Teachers College, Huzhou, China.
authors.forename: Zhen-Hai
authors.identifier: 0000-0003-2809-6692
authors.initials: ZH
authors.lastname: Fei
authors.affiliation: Department of Neurosurgery, The First Affiliated Hospital of Huzhou Teachers College, Huzhou, China.
authors.forename: Yi-Qi
authors.identifier: 0000-0002-9488-1165
authors.initials: YQ
authors.lastname: Wang
authors.affiliation: Department of Neurosurgery, The First Affiliated Hospital of Huzhou Teachers College, Huzhou, China.
authors.forename: Jian-Guo
authors.identifier: 0000-0001-8093-6260
authors.initials: JG
authors.lastname: Yang
authors.affiliation: Department of Neurosurgery, The First Affiliated Hospital of Huzhou Teachers College, Huzhou, China.
authors.forename: Chao-Hui
authors.identifier: 0000-0002-7757-0250
authors.initials: CH
authors.lastname: Zhao
authors.affiliation: Department of Neurosurgery, The First Affiliated Hospital of Huzhou Teachers College, Huzhou, China.
authors.forename: Yong
authors.identifier: 0000-0002-9891-1368
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Department of Neurosurgery, The First Affiliated Hospital of Huzhou Teachers College, Huzhou, China.
authors.forename: Xing-Ming
authors.identifier: 0000-0002-7906-7843
authors.initials: XM
authors.lastname: Zhong
keywords: Angiopoietin-1; Angiopoietin-2; Blood-Brain Barrier; Brain Injuries; Subarachnoid Hemorrhage