Ischemic preconditioning prevents free radical production and mitochondrial depolarization in small-for-size rat liver grafts

Hasibur Rehman, Henry D. Connor, Venkat K. Ramshesh, Tom P. Theruvath, Ronald P. Mason, Gary L. Wright, John J. Lemasters, Zhi Zhong

Research output: Contribution to journalArticlepeer-review

31 Scopus citations


BACKGROUND. Ischemic preconditioning (IP) renders tissues more tolerant to subsequent longer episodes of ischemia. This study tested whether IP attenuates injury of small-for-size liver grafts by preventing free radical production and mitochondrial dysfunction. METHODS. IP was induced by clamping the portal vein and hepatic artery for 9 min. Livers were harvested 5 min after releasing the clamp. Mitochondrial polarization and cell death were assessed by intravital confocal/multiphoton microscopy of rhodamine 123 (Rh123) and propidium iodide. Free radicals were trapped with α-(4-pyridyl 1-oxide)-N-tert-butylnitrone and measured using electron spin resonance. RESULTS. After quarter-size liver transplantation, alanine aminotransferase, serum bilirubin, necrosis, and apoptosis all increased. IP blocked these increases by more than 58%. 5-Bromo-2′-deoxyuridine labeling and increases of graft weight were only ∼3% and 0.2% in quarter-size grafts without IP, respectively, but increased to 32% and 60% in ischemic-preconditioned grafts, indicating better liver regeneration. Eighteen hours after implantation, viable cells with depolarized mitochondria in quarter-size grafts were 15 per high power field, and dead cells were less than 1 per high power field, indicating that depolarization preceded necrosis. A free radical adduct signal was detected in bile from quarter-size grafts. IP decreased this free radical formation and prevented mitochondrial depolarization. IP did not increase heat shock proteins 10, 27, 32, 60, 70, 72, 75 and Cu/Zn-superoxide dismutase (SOD) but increased heat shock protein-90, a chaperone that facilitates protein import into mitochondria, and mitochondrial Mn-SOD. CONCLUSION. Taken together, IP decreases injury and improves regeneration of small-for-size liver grafts, possibly by increasing mitochondrial Mn-SOD, thus protecting against free radical production and mitochondrial dysfunction.

Original languageEnglish (US)
Pages (from-to)1322-1331
Number of pages10
Issue number9
StatePublished - May 2008
Externally publishedYes


  • Free radical
  • Heat shock protein
  • Ischemic preconditioning
  • Mitochondrial permeability transition
  • Partial liver transplantation

ASJC Scopus subject areas

  • Transplantation


Dive into the research topics of 'Ischemic preconditioning prevents free radical production and mitochondrial depolarization in small-for-size rat liver grafts'. Together they form a unique fingerprint.

Cite this