title: Measurement of free radicals using electron paramagnetic resonance spectroscopy during open aorto-iliac arterial reconstruction.
abstract: BACKGROUND
  Aortic cross-clamping during abdominal aortic aneurysm (AAA) open repair leads to development of ischemia-reperfusion injury. Electron paramagnetic resonance spectroscopy (EPR) spin-trapping is a valuable method of direct measurement of free radicals. The objective of the study was to evaluate the results of EPR as a direct method of free radical measurement and degree of inflammatory response in open operative treatment of patients with AAA and aorto-iliac occlusive disease (AIOD).
  
  
  METHODS
  The study was performed on a group of 32 patients with AAA and 25 patients with AIOD scheduled for open repair. Peripheral venous blood for EPR spectroscopy and for SOD, GPx, ox-LDL, Il-6, TNF-alfa, CRP, and HO-1 were harvested. Selected parameters were established accordingly to specified EPR and immunohistochemical methods and analyzed between groups by Mann-Whitney U test and Wilcoxon matched-pairs signed-ranks test with Bonferroni correction.
  
  
  RESULTS
  Free radicals level was correlated with the time of the aortic cross-clamping after the reperfusion of he first and second leg in AAA (r=0.7; r=0.47). ox-LDL in AAA decreased 5 min after reperfusion of the first leg (32.99 U/L, range: 14.09-77.12) and 5 min after reperfusion of the second leg (26.75 U/L, range: 11.56-82.12) and 24 h after the operation (25.85 U/L, range: 14.29-49.70). HO-1 concentration increased to above the level before intervention 24 h after surgery. The activities of GPx and SOD decreased 5 min after the first-leg reperfusion in AAA. Twenty-four hours after surgery, inflammatory markers increased in AAA to CRP was 14.76 ml/l (0.23-38.55), IL-6 was 141.22 pg/ml (84.3-591.03), TNF-alfa was 6.82 pg/ml (1.76-80.01) and AIOD: CRP was 18.44 mg/l (2.56-33.14), IL-6: 184.1 pg/ml (128.46-448.03), TNF-alfa was 7.74 pg/ml (1.74-74.74).
  
  
  CONCLUSIONS
  EPR spin-trapping demonstrates temporarily elevated level of free radicals in early phase of reperfusion, leading to decrease antioxidants in AAA. Elevated free radical levels decreased 24 h after surgery due to various endogenous antioxidants and therapies.
authors.affiliation: Department of General and Vascular Surgery, Poznań University of Medical Sciences, Poznań, Poland.
authors.forename: Wacław
authors.initials: W
authors.lastname: Majewski
authors.affiliation: Institute of Physics, Adam Mickiewicz University, Division of Medical Physics, Poznań, Poland.
authors.forename: Ryszard
authors.initials: R
authors.lastname: Krzyminiewski
authors.affiliation: Department of General and Vascular Surgery, Poznań University of Medical Sciences, Poznań, Poland.
authors.forename: Michał
authors.initials: M
authors.lastname: Stanisić
authors.affiliation: Department of General Chemistry, Poznań University of Medical Sciences, Poznań, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Iskra
authors.affiliation: Department of General and Vascular Surgery, Poznań University of Medical Sciences, Poznań, Poland.
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Krasiński
authors.affiliation: Department of General and Vascular Surgery, Poznań University of Medical Sciences, Poznań, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Nowak
authors.affiliation: Institute of Physics, Adam Mickiewicz University, Division of Medical Physics, Poznań, Poland.
authors.forename: Bernadeta
authors.initials: B
authors.lastname: Dobosz
mesh_terms: D000368:Aged; D001011:Aorta / Q000601:surgery*; D017544:Aortic Aneurysm, Abdominal / Q000097:blood / Q000601:surgery; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005260:Female; D005609:Free Radicals / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000378:metabolism; D051547:Heme Oxygenase-1 / Q000378:metabolism; D006801:Humans; D007085:Ilium / Q000601:surgery*; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D019651:Plastic Surgery Procedures; D013482:Superoxide Dismutase / Q000378:metabolism; D014656:Vascular Surgical Procedures
chemical_list: D005609:Free Radicals; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D051547:Heme Oxygenase-1; D013482:Superoxide Dismutase