title: Pretreatment of liver grafts in vivo by γ-aminobutyric acid receptor regulation reduces cold ischemia/warm reperfusion injury in rat.
abstract: BACKGROUND
  Gamma-aminobutyric acid (GABA) is found throughout the body. The regulation of GABA receptor (GABAR) reduces oxidative stress (OS). Ischemia/reperfusion injury after orthotopic liver transplantation (OLT) causes OS-induced graft damage. The effects of GABAR regulation in donors in vivo were investigated.
  
  
  METHODS
  Donor rats received saline, a GABAR agonist or GABAR antagonist 4 h before surgery. Recipient rats were divided into four groups according to the donor treatments: laparotomy, OLT with saline, OLT with GABAR agonist and OLT with GABAR antagonist. Histopathological, biochemical and immunohistological examinations were performed at 6, 12 and 24 h after OLT. Protein assays were performed at 6 h after OLT. The 4-hydroxynonenal (4-HNE), ataxia-telangiectasia mutated kinase (ATM), phosphorylated histone H2AX (gammaH2AX), phosphatidylinositol-3 kinase (PI3K), Akt and superoxide dismutase (SOD) were assessed by western blot analysis.
  
  
  RESULTS
  In the univariate analysis, histopathological and biochemical profiles verified that the GABAR agonist reduced graft damage. Immunohistology revealed that the GABAR agonist prevented the induction of apoptosis. Measurement of 4-4-HNE levels confirmed OS-induced damage after OLT, and the GABAR agonist improved this damage. In the gammaH2AX, PI3K, Akt and antioxidant enzymes (SODs), ATM and H2AX were greatly increased after OLT, and were reduced by the GABAR agonist. In the multivariate analyses between multiple groups, histopathological assessment, aspartate aminotransferase level, immunohistological examinations for apoptotic induction and gammaH2AX showed statistical differences.
  
  
  CONCLUSIONS
  A specific agonist demonstrated regulation of GABAR in vivo in the liver. This activation in vivo reduced OS after OLT via the ATM/H2AX pathway.
authors.affiliation: Department of Neuroscience, Mayo Clinic in Florida, Jacksonville, FL, USA. horit@kuhp.kyoto-u.ac.jp
authors.forename: Tomohide
authors.initials: T
authors.lastname: Hori
authors.forename: Lindsay B
authors.initials: LB
authors.lastname: Gardner
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Hata
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Ann-Marie T
authors.initials: AM
authors.lastname: Baine
authors.forename: Shinji
authors.initials: S
authors.lastname: Uemoto
authors.forename: Justin H
authors.initials: JH
authors.lastname: Nguyen
mesh_terms: D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins / Q000378:metabolism; D001640:Bicuculline / Q000008:administration & dosage; D050377:Cold Ischemia / Q000009:adverse effects; D004260:DNA Repair / Q000187:drug effects; D018755:GABA Agonists / Q000008:administration & dosage*; D018756:GABA Antagonists / Q000008:administration & dosage*; D006657:Histones / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D016031:Liver Transplantation / Q000379:methods*; D008297:Male; D009118:Muscimol / Q000008:administration & dosage; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D011917:Rats, Inbred Lew; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D015398:Signal Transduction / Q000187:drug effects; D052096:Warm Ischemia / Q000009:adverse effects
chemical_list: D018755:GABA Agonists; D018756:GABA Antagonists; D006657:Histones; D009118:Muscimol; D064007:Ataxia Telangiectasia Mutated Proteins; D001640:Bicuculline