title: Remote ischemic perconditioning protects the liver from ischemia-reperfusion injury.
abstract: BACKGROUND
  Ischemia-reperfusion (IR)-induced injury is a frequent sequel of major liver resections. IR injury after prolonged surgical interventions could be the source of increased risk of postoperative morbidity and mortality. Hepatoprotective effects of this new feasible method called remote ischemic perconditioning (RIPER) were investigated in our rat model of IR injury.
  
  
  METHODS
  Male Wistar rats underwent ischemia for 60 min on two-thirds of their livers, followed by 1, 6, and 24 h of reperfusion (n = 72, 8 per group). During liver ischemia, but before reperfusion, rats in the treated groups received four cycles of brief infrarenal aortic clamping as perconditioning. Liver microcirculation was monitored by laser Doppler flowmeter parallel with mean arterial pressure measurements. Liver tissue injury and redox homeostasis were investigated. Furthermore, serum tumor necrosis factor alpha (TNF-α) levels were measured.
  
  
  RESULTS
  In the RIPER group, compared with the IR group, serum transaminase levels were significantly lower after each reperfusion period (alanine aminotransferase: 1 h, P < 0.001; 6 h, P < 0.05; 24 h, P < 0.01 and aspartate aminotransferase: 1 h, P < 0.001; 6 h, P < 0.05; 24 h, P < 0.05). Reperfusion microcirculatory parameters significantly improved in the perconditioned group compared with those in the IR group (reperfusion area: P = 0.005; maximal plateau: P = 0.0002). Regarding TNF-α levels, significant differences were detected between the two IR injured groups (RIPER versus IR: 1 h, 34.3 ± 12.8 pg/mL versus 205.7 ± 60.9 pg/mL, P < 0.001; 6 h, 60.6 ± 11.7 pg/mL versus 110.4 ± 21.6 pg/mL, P < 0.05). Results of the histologic assessment and redox state measurements also showed favorable changes.
  
  
  CONCLUSIONS
  Our team firstly reported the protective effects of RIPER on liver morphology, redox homeostasis, and microcirculation and proposed the changes of TNF-α expression.
authors: 1st Department of Surgery, Semmelweis University, Budapest, Hungary.
authors: Zoltán
authors: Z
authors: Czigány
authors: Zsolt
authors: Z
authors: Turóczi
authors: Péter
authors: P
authors: Ónody
authors: László
authors: L
authors: Harsányi
authors: Gábor
authors: G
authors: Lotz
authors: Viktor
authors: V
authors: Hegedüs
authors: Attila
authors: A
authors: Szijártó
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001219:Aspartate Aminotransferases / Q000097:blood; D004195:Disease Models, Animal; D005609:Free Radicals / Q000378:metabolism; D019194:Ischemic Preconditioning / Q000379:methods*; D017078:Laser-Doppler Flowmetry; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000378:metabolism; D008102:Liver Circulation / Q000502:physiology; D008107:Liver Diseases / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000517:prevention & control*; D008297:Male; D008833:Microcirculation / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000517:prevention & control*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D014463:Ultrasonography
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D014409:Tumor Necrosis Factor-alpha; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase
keywords: Ischemia; Liver; Microcirculation; Perconditioning; Remote conditioning; Reperfusion; TNF-α