title: Inhaled nickel nanoparticles alter vascular reactivity in C57BL/6 mice.
abstract: BACKGROUND
  The use of nanoparticles (NPs) in technological applications is rapidly expanding, but the potential health effects associated with NP exposure are still largely unknown. Given epidemiological evidence indicating an association between inhaled ambient ultrafine particles and increased risk of cardiovascular disease morbidity and mortality, it has been suggested that exposure to NPs via inhalation may induce similar cardiovascular responses.
  
  
  METHODS
  Male C57BL/6 mice were exposed via whole-body inhalation to either filtered air (FA) or nickel hydroxide (NH) NPs (100, 150, or 900 µg/m(3)) for 1, 3, or 5 consecutive days (5 h/day). At 24-h post-exposure, vascular function in response to a vasoconstrictor, phenylephrine (PE), and a vasodilator, acetylcholine (ACh), was measured in the carotid artery.
  
  
  RESULTS
  Carotid arteries from mice exposed to all concentrations of NH-NPs showed statistically significant differences in graded doses of PE-induced contractile responses compared with those from FA mice. Similarly, vessels from NH-NP-exposed mice also demonstrated impaired vasorelaxation following graded doses of ACh as compared with FA mice.
  
  
  CONCLUSIONS
  These results suggest that short-term exposure to NH-NPs can induce acute endothelial disruption and alter vasoconstriction and vasorelaxation. These findings are consistent with other studies assessing vascular tone and function in the aorta, coronary, and mesenteric vessels from mice exposed to motor vehicular exhaust and concentrated ambient particles.
authors.affiliation: Department of Environmental Medicine, New York University School of Medicine, Tuxedo, NY, USA.
authors.forename: Azita K
authors.initials: AK
authors.lastname: Cuevas
authors.forename: Eric N
authors.initials: EN
authors.lastname: Liberda
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Gillespie
authors.forename: Jorge
authors.initials: J
authors.lastname: Allina
authors.forename: Lung Chi
authors.initials: LC
authors.lastname: Chen
mesh_terms: D000109:Acetylcholine / Q000032:analysis; D000393:Air Pollutants / Q000633:toxicity*; D000818:Animals; D001011:Aorta / Q000503:physiopathology; D002339:Carotid Arteries / Q000503:physiopathology; D019570:Inhalation Exposure / Q000009:adverse effects*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009131:Muscle, Smooth, Vascular / Q000098:blood supply; D053758:Nanoparticles / Q000633:toxicity*; D009532:Nickel / Q000633:toxicity*; D010316:Particle Size; D014661:Vasoconstriction / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000032:analysis
chemical_list: D000393:Air Pollutants; D014665:Vasodilator Agents; D009532:Nickel; D000109:Acetylcholine