title: LPS-induced endotoxic shock does not cause early brain edema formation - an MRI study in rats.
abstract: OBJECTIVE
  Early microcirculatory failure is assumed as a key factor in the development of a septic encephalopathy. However, brain edema is also a common finding in sepsis syndromes possibly interfering with the vasoregulative mechanisms of the brain. We assessed the occurrence of brain edema in a rat model of endotoxic shock.
  
  
  METHODS
  Eleven mechanically ventilated male CD-rats.
  
  
  METHODS
  Intravenous application of 5 mg/kg LPS (n = 8) or vehicle (n = 3).
  
  
  METHODS
  Apparent diffusion coefficient (ADC) and T2-relaxation time (T2RT) were quantified on cerebral MRI at baseline and repeatedly for up to 3.5 h after LPS-injection. Change in blood pressure was compensated with norepinephrine. Brain water content was quantified using the wet/dry method.
  
  
  RESULTS
  All LPS-treated rats developed endotoxic shock. No significant difference in T2RT or ADC was detectable before and after LPS-injection (T2RT: baseline 60.33 +/- 1.21; after 3.5 h 60.15 +/- 0.59; ADC: baseline 6.86 +/- 0.51; after 3.5 h 6.75 +/- 0.33). Post-mortem analysis did not indicate a difference in brain water content between septic and non-septic animals.
  
  
  CONCLUSIONS
  Reports of early microcirculatory failure seem not to be related to the occurrence of early (< or =3.5 h) brain edema.
authors.affiliation: Department of Neurology, Justus-Liebig University of Giessen, Giessen, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Rosengarten
authors.forename: M
authors.initials: M
authors.lastname: Walberer
authors.forename: J
authors.initials: J
authors.lastname: Allendoerfer
authors.forename: C
authors.initials: C
authors.lastname: Mueller
authors.forename: N
authors.initials: N
authors.lastname: Schwarz
authors.forename: G
authors.initials: G
authors.lastname: Bachmann
authors.forename: T
authors.initials: T
authors.lastname: Gerriets
mesh_terms: D000818:Animals; D001834:Body Water / Q000378:metabolism; D001929:Brain Edema / Q000209:etiology / Q000473:pathology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D038524:Diffusion Magnetic Resonance Imaging; D004195:Disease Models, Animal; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D008833:Microcirculation / Q000502:physiology; D051381:Rats; D012772:Shock, Septic / Q000139:chemically induced / Q000473:pathology
chemical_list: D008070:Lipopolysaccharides