title: [Correlation and influences of inflammatory mediators on permeability of the blood-brain barrier at high altitude exposure].
abstract: OBJECTIVE
  To investigate the influences of inflammatory mediator on permeability of the blood-brain barrier(BBB) at high altitude environmental exposure as well as relationship and water content in brain.
  
  
  METHODS
  Wistar rats were exposed to different altitude gradients, then brain tissue homogenate was prepared, and the activities of tumor necrosis factor-alpha (TNFalpha) and endothelin (ET) in brain tissue homogenate were measured by radioimmunoassay methods. The activities of nitric oxide (NO) in brain tissue homogenate were measured by chemical methods. The evans blue (EB) content in brain tissue was determined by colorimetry and the wet weight/dry weight ratio (W/D) was used to express the water content in brain.
  
  
  RESULTS
  With altitude going up, the activities of TNFalpha, NO and ET in the brain of rats rose, and they also rose gradually with time prolonging under high altitude hypoxia exposure. Their most obvious rise was seen during 9 days after ascending 5 000 m high altitude regions. At the same time, the EB and water content in the brain of mice showed the same change trends. Therefore, the inflammatory mediator activity and EB content as well as water content in brain showed an evidently linear relationship.
  
  
  CONCLUSIONS
  The inflammatory mediator plays an important role in the change of permeability of BBB. It's a critical inducing factor in the change of permeability of BBB under high altitude exposure.
authors.affiliation: Department of Pathophysiology and High Altitude Physiology, College of High Altitude Military Medicine, Third Military Medical University, Chongqing 400038, China. zhouqq99@sohu.com
authors.forename: Qi-Quan
authors.initials: QQ
authors.lastname: Zhou
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Yun-Li
authors.initials: YL
authors.lastname: Wang
authors.forename: Ai-Dong
authors.initials: AD
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Cheng
mesh_terms: D000531:Altitude; D000532:Altitude Sickness / Q000378:metabolism*; D000818:Animals; D001812:Blood-Brain Barrier / Q000502:physiology*; D001929:Brain Edema / Q000209:etiology / Q000378:metabolism*; D002199:Capillary Permeability; D002560:Cerebrovascular Circulation; D016232:Endothelins / Q000378:metabolism; D005260:Female; D000860:Hypoxia / Q000378:metabolism; D018836:Inflammation Mediators / Q000502:physiology*; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D010539:Permeability; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D016232:Endothelins; D018836:Inflammation Mediators; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide