title: Angiopoietin-1 is associated with cerebral vasospasm and delayed cerebral ischemia in subarachnoid hemorrhage.
abstract: BACKGROUND
  Angiopoietin-1 (Ang-1) and -2 (Ang-2) are keyplayers in the regulation of endothelial homeostasis and vascular proliferation. Angiopoietins may play an important role in the pathophysiology of cerebral vasospasm (CVS). Ang-1 and Ang-2 have not been investigated in this regard so far.
  
  
  METHODS
  20 patients with subarachnoid hemorrhage (SAH) and 20 healthy controls (HC) were included in this prospective study. Blood samples were collected from days 1 to 7 and every other day thereafter. Ang-1 and Ang-2 were measured in serum samples using commercially available enzyme-linked immunosorbent assay. Transcranial Doppler sonography was performed to monitor the occurrence of cerebral vasospasm.
  
  
  RESULTS
  SAH patients showed a significant drop of Ang-1 levels on day 2 and 3 post SAH compared to baseline and HC. Patients, who developed Doppler sonographic CVS, showed significantly lower levels of Ang-1 with a sustained decrease in contrast to patients without Doppler sonographic CVS, whose Ang-1 levels recovered in the later course of the disease. In patients developing cerebral ischemia attributable to vasospasm significantly lower Ang-1 levels have already been observed on the day of admission. Differences of Ang-2 between SAH patients and HC or patients with and without Doppler sonographic CVS were not statistically significant.
  
  
  CONCLUSIONS
  Ang-1, but not Ang-2, is significantly altered in patients suffering from SAH and especially in those experiencing CVS and cerebral ischemia. The loss of vascular integrity, regulated by Ang-1, might be in part responsible for the development of cerebral vasospasm and subsequent cerebral ischemia.
authors: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors: Marlene
authors: M
authors: Fischer
authors: Gregor
authors: G
authors: Broessner
authors: Anelia
authors: A
authors: Dietmann
authors: Ronny
authors: R
authors: Beer
authors: Raimund
authors: R
authors: Helbok
authors: Bettina
authors: B
authors: Pfausler
authors: Andreas
authors: A
authors: Chemelli
authors: Erich
authors: E
authors: Schmutzhard
authors: Peter
authors: P
authors: Lackner
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