title: Longitudinal quantification of radical bursts during pulmonary ischaemia and reperfusion.
abstract: OBJECTIVE
  Pulmonary ischaemia-reperfusion injury (IRI) is associated with several life-threatening pulmonary disorders, and may severely compromise the outcome of lung transplantation. Highly reactive molecules such as superoxide, nitric oxide (NO) and peroxynitrite (ONOO(-)) are presumed to contribute to IRI pathogenesis, but this assumption is based on indirect measurements. We use electron spin resonance (ESR) to directly quantify free radical formation after pulmonary ischaemia and reperfusion.
  
  
  METHODS
  Five groups of 10 Swiss mice were subjected to left pulmonary hilum clamping for 1 h of ischaemia followed by 0, 1, 4 and 24 h of reperfusion or to sham thoracotomy alone as control procedure. In five mice per group, ESR was used to measure iron-diethyldithio-carbamate trihydrate-trapped NO in the lung. In the other group of 5, reactive oxygen species generation in the lung and in blood was quantified with ESR by detection of ascorbyl radical and CMH spin probe, respectively. Pulmonary ONOO(-) was monitored with nitrotyrosine Western blotting.
  
  
  RESULTS
  After 1 h of reperfusion, a pulmonary NO peak (14.69 ± 0.91 × 10(4) Arbitrary Units (A.U.). vs 1.84 ± 0.75 × 10(4) A.U. in sham; P < 0.001) coincided with a significant increase in nitrosated proteins (0.105 ± 0.015 A.U.) compared with sham (0.047 ± 0.006 A.U.); P < 0.005). Peripheral blood showed a significant free radical burst after 1 h of ischaemia (11 774 ± 728 A.U. vs 6660 ± 833 A.U. in sham; P < 0.001).
  
  
  CONCLUSIONS
  Longitudinal quantification of free radicals during IRI reveals the occurrence of two major radical bursts. The radical peak in peripheral blood after ischaemia may be related to systemic hypoxia. After 1 h of reperfusion, the lung tissue shows a significant increase of superoxide, NO and their reaction products, which are probably involved in IRI pathogenesis.
authors.affiliation: Antwerp Surgical Training and Research Center (ASTARC), Antwerp University, Antwerp, Belgium Laboratory for Microbiology, Parasitology and Hygiene, Antwerp University, Antwerp, Belgium Department of Thoracic and Vascular Surgery, Antwerp University Hospital, Antwerp, Belgium jangielis@live.be.
authors.forename: Jan F
authors.initials: JF
authors.lastname: Gielis
authors.affiliation: Laboratory for Microbiology, Parasitology and Hygiene, Antwerp University, Antwerp, Belgium.
authors.forename: Gaëlle A
authors.initials: GA
authors.lastname: Boulet
authors.affiliation: Department of Toxicogenomics, Maastricht University, Maastricht, Netherlands.
authors.forename: Jacob J
authors.initials: JJ
authors.lastname: Briedé
authors.affiliation: Laboratory for Microbiology, Parasitology and Hygiene, Antwerp University, Antwerp, Belgium.
authors.forename: Tessa
authors.initials: T
authors.lastname: Horemans
authors.affiliation: Antwerp Surgical Training and Research Center (ASTARC), Antwerp University, Antwerp, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Debergh
authors.affiliation: Antwerp Surgical Training and Research Center (ASTARC), Antwerp University, Antwerp, Belgium.
authors.forename: Max
authors.initials: M
authors.lastname: Kussé
authors.affiliation: Antwerp Surgical Training and Research Center (ASTARC), Antwerp University, Antwerp, Belgium.
authors.forename: Paul
authors.initials: P
authors.lastname: Cos
authors.affiliation: Antwerp Surgical Training and Research Center (ASTARC), Antwerp University, Antwerp, Belgium Department of Thoracic and Vascular Surgery, Antwerp University Hospital, Antwerp, Belgium.
authors.forename: Paul E Y
authors.initials: PE
authors.lastname: Van Schil
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D005069:Evaluation Studies as Topic; D005260:Female; D005609:Free Radicals / Q000378:metabolism*; D008168:Lung / Q000098:blood supply*; D016040:Lung Transplantation / Q000009:adverse effects; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology; D011897:Random Allocation; D017382:Reactive Oxygen Species / Q000378:metabolism; D015427:Reperfusion Injury / Q000378:metabolism* / Q000503:physiopathology*; D012680:Sensitivity and Specificity; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D005609:Free Radicals; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D013482:Superoxide Dismutase
keywords: Free radicals; Ischaemia–reperfusion injury; Nitric oxide; Oxidative stress