title: Neuroprotective effects of argon in an in vivo model of transient middle cerebral artery occlusion in rats.
abstract: OBJECTIVE
  The neuroprotective effects of the noble gas xenon are well known. Argon, in contrast to xenon, is abundant, inexpensive, and therefore widely applicable. In this study, we analyzed the possible neuroprotective role of argon in an in vivo rat model of acute focal cerebral ischemia.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Academic research laboratory.
  
  
  METHODS
  Male adult Sprague-Dawley rats.
  
  
  METHODS
  Twenty-two rats underwent 2 hrs of transient middle cerebral artery occlusion using the endoluminal thread model. One hr after transient middle cerebral artery occlusion induction, spontaneously breathing rats received either 50 vol % argon/50 vol % O2 (argon group, n = 11) or 50 vol % N2/50 vol % O2 (control group, n = 11) for 1 hr through a face mask. Twenty-four hrs after reperfusion, rats were neurologically and behaviorally tested and euthanized. Rat brains were stained with 2,3,5-triphenyltetrazolium chloride and infarct volumes determined by planimetry.
  
  
  RESULTS
  After 2 hrs of transient middle cerebral artery occlusion in the rat, we found in the argon group a significant reduction in the overall (p = .004) and after subdivision in the cortical (p = .007) and the basal ganglia (p = .02) infarct volumes. Argon treatment resulted in a significant improvement of the composite adverse outcome (p = .034). However, there was no advantage in acute survival 24 hrs after transient middle cerebral artery occlusion (p = .361).
  
  
  CONCLUSIONS
  We were able to demonstrate argon's neuroprotective effects in an in vivo experimental rat model of acute focal cerebral ischemia. Animals breathing spontaneously 50 vol % argon 1 hr after induction of transient middle cerebral artery occlusion for 1 hr by face mask showed significantly reduced infarct volumes and composite adverse outcomes.
authors.affiliation: Department of Neurosurgery, Klinikum rechts der Isar, Hospital of the Technical University Munich, Munich, Germany.
authors.forename: Yu-Mi
authors.initials: YM
authors.lastname: Ryang
authors.forename: Astrid V
authors.initials: AV
authors.lastname: Fahlenkamp
authors.forename: Rolf
authors.initials: R
authors.lastname: Rossaint
authors.forename: Dominik
authors.initials: D
authors.lastname: Wesp
authors.forename: Philip D
authors.initials: PD
authors.lastname: Loetscher
authors.forename: Cordian
authors.initials: C
authors.lastname: Beyer
authors.forename: Mark
authors.initials: M
authors.lastname: Coburn
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D001128:Argon / Q000627:therapeutic use*; D002560:Cerebrovascular Circulation / Q000502:physiology; D004195:Disease Models, Animal; D020244:Infarction, Middle Cerebral Artery / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D018696:Neuroprotective Agents; D001128:Argon