title: Exposure to nitrogen dioxide is not associated with vascular dysfunction in man.
abstract: BACKGROUND
  Exposure to air pollution is associated with increased cardiorespiratory morbidity and mortality. It is unclear whether these effects are mediated through combustion-derived particulate matter or gaseous components, such as nitrogen dioxide.
  
  
  OBJECTIVE
  To investigate the effect of nitrogen dioxide exposure on vascular vasomotor and six fibrinolytic functions.
  
  
  METHODS
  Ten healthy male volunteers were exposed to nitrogen dioxide at 4 ppm or filtered air for 1 h during intermittent exercise in a randomized double-blind crossover study. Bilateral forearm blood flow and fibrinolytic markers were measured before and during unilateral intrabrachial infusion of bradykinin (100-1000 pmol/min), acetylcholine (5-20 microg/min), sodium nitroprusside (2-8 microg/min), and verapamil (10-100 microg/min) 4 h after the exposure. Lung function was determined before and after the exposure, and exhaled nitric oxide at baseline and 1 and 4 h after the exposure.
  
  
  RESULTS
  There were no differences in resting forearm blood flow after either exposure. There was a dose-dependent increase in forearm blood flow with all vasodilators but this was similar after either exposure for all vasodilators (p > .05 for all). Bradykinin caused a dose-dependent increase in plasma tissue-plasminogen activator, but again there was no difference between the exposures. There were no changes in lung function or exhaled nitric oxide following either exposure.
  
  
  CONCLUSIONS
  Inhalation of nitrogen dioxide does not impair vascular vasomotor or fibrinolytic function. Nitrogen dioxide does not appear to be a major arbiter of the adverse cardiovascular effects of air pollution.
authors.affiliation: Centre for Cardiovascular Sciences, University of Edinburgh, United Kingdom.
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Langrish
authors.forename: Magnus
authors.initials: M
authors.lastname: Lundbäck
authors.forename: Stefan
authors.initials: S
authors.lastname: Barath
authors.forename: Stefan
authors.initials: S
authors.lastname: Söderberg
authors.forename: Nicholas L
authors.initials: NL
authors.lastname: Mills
authors.forename: David E
authors.initials: DE
authors.lastname: Newby
authors.forename: Thomas
authors.initials: T
authors.lastname: Sandström
authors.forename: Anders
authors.initials: A
authors.lastname: Blomberg
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000378:metabolism / Q000633:toxicity*; D001772:Blood Cell Count; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects / Q000473:pathology; D015444:Exercise / Q000502:physiology; D005342:Fibrinolysis / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D019570:Inhalation Exposure; D008168:Lung / Q000187:drug effects; D008297:Male; D009585:Nitrogen Dioxide / Q000378:metabolism / Q000633:toxicity*; D010083:Oxidants, Photochemical / Q000378:metabolism / Q000633:toxicity*; D010960:Plasminogen Activators / Q000378:metabolism; D012129:Respiratory Function Tests; D013147:Spirometry; D013927:Thrombosis / Q000097:blood; D014652:Vascular Diseases / Q000139:chemically induced* / Q000453:epidemiology / Q000473:pathology; D055815:Young Adult
chemical_list: D000395:Air Pollutants, Occupational; D010083:Oxidants, Photochemical; D010960:Plasminogen Activators; D009585:Nitrogen Dioxide