title: The relationship between IL-6, ET-1 and cerebral vasospasm, in experimental rabbit subarachnoid hemorrhage.
abstract: BACKGROUND
  In subarachnoid hemorrhage (SAH), occurrence of cerebral vasospasm (CVS) mediated by endothelin (ET)-1 might be a result of a compartmental inflammatory response with interleukin (IL)-6 release. We aim to investigate the relationship between ET-1 and IL-6 in association of CVS.
  
  
  METHODS
  A total of 24 New Zealand white rabbits where randomly allocated into 3 groups: SAH (N.=10), IL-6 (N.=10), and sham (N.=4). SAH was induced by a closed cranium extracranial-intracranial shunt model. In the IL-6 group, IL-6 was injected into the cisterna magna. CVS of the basilar artery was assessed by digital subtraction angiography. IL-6 and ET-1 concentrations were measured using enzyme-linked immunosorbent assay. Neuronal damage was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling.
  
  
  RESULTS
  A significant increase between baseline (day 0) and follow-up (day 3) was found in CSF IL-6 levels of animals in the SAH and IL-6 group. There was a statistically significant correlation between IL-6 and ET-1 levels in the CSF (Pearson's r=0.454, P=0.003). CVS at day 3 was more pronounced in the SAH than in the IL-6 group: 26.0 ±7.2 % and 16.7 ±5.0 % respectively. TUNEL positive apoptotic neurons in the hippocampal formation were present in the SAH group and in a lesser degree in the IL-6 group.
  
  
  CONCLUSIONS
  The results indicate that IL-6 triggered CVS after SAH is ET-1 dependent. IL-6 may be a target for new therapeutic approaches.
authors.affiliation: Department of Neurosurgery, Kantonsspital Aarau, Aarau, Switzerland - neurosurgery@ksa.ch.|Neuro Lab, Research Group for Experimental Neurosurgery and Neurocritical Care, Department of Intensive Care Medicine, University Hospital and University of Bern, Bern, Switzerland - neurosurgery@ksa.ch.
authors.forename: Davide
authors.initials: D
authors.lastname: Croci
authors.affiliation: Department of Neurosurgery, Kantonsspital Aarau, Aarau, Switzerland.|Neuro Lab, Research Group for Experimental Neurosurgery and Neurocritical Care, Department of Intensive Care Medicine, University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Edin
authors.initials: E
authors.lastname: Nevzati
authors.affiliation: Department of Neurosurgery, Kantonsspital Aarau, Aarau, Switzerland.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Danura
authors.affiliation: Department of Neurosurgery, Kantonsspital Aarau, Aarau, Switzerland.
authors.forename: Salome
authors.initials: S
authors.lastname: Schöpf
authors.affiliation: Department of Neurosurgery, Kantonsspital Aarau, Aarau, Switzerland.|Neuro Lab, Research Group for Experimental Neurosurgery and Neurocritical Care, Department of Intensive Care Medicine, University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Javier
authors.initials: J
authors.lastname: Fandino
authors.affiliation: Department of Neurosurgery, Kantonsspital Aarau, Aarau, Switzerland.|Neuro Lab, Research Group for Experimental Neurosurgery and Neurocritical Care, Department of Intensive Care Medicine, University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Serge
authors.initials: S
authors.lastname: Marbacher
authors.affiliation: Department of Neurosurgery, Kantonsspital Aarau, Aarau, Switzerland.|Neuro Lab, Research Group for Experimental Neurosurgery and Neurocritical Care, Department of Intensive Care Medicine, University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Carl
authors.initials: C
authors.lastname: Muroi
mesh_terms: D000818:Animals; D019332:Endothelin-1 / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism*; D011817:Rabbits; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000378:metabolism*; D020301:Vasospasm, Intracranial / Q000209:etiology / Q000378:metabolism*
chemical_list: D019332:Endothelin-1; D015850:Interleukin-6