Organ Transplantation Research Today is a free monthly online journal that collates and summarizes the latest research about Organ Transplantation, including details on risks, prognosis, procedure, surgery. | ||||||||
|
Free radical-dependent dysfunction of small-for-size rat liver grafts: prevention by plant polyphenols.Zhong Z, Connor HD, Froh M, Bunzendahl H, Lind H, Lehnert M, Mason RP, Thurman RG, Lemasters JJ Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, 27599, USA. zzhong@med.unc.edu BACKGROUND & AIMS: The mechanisms by which small-for-size liver grafts decrease survival remain unclear. This study investigated the role of free radicals in injury to small-for-size grafts. METHODS: Rat liver explants were reduced in size ex vivo and transplanted into recipients of the same or greater body weight, resulting in a graft weight and standard liver weight of approximately 50% and 25%, respectively. A polyphenol extract from Camellia sinenesis (20 microg/mL) or an equivalent concentration of epicatechin was added to the storage solution and the lactated Ringer poststorage rinse solution. RESULTS: Serum alanine aminotransferase release increased from approximately 60 U/L before implantation to 750, 1410, and 2520 U/L after full-size, half-size, and quarter-size transplantation, respectively. Total bilirubin increased slightly after transplantation of full-size and half-size grafts but increased 104-fold in quarter-size grafts. In quarter-size grafts, histological changes included necrosis, leukocyte infiltration, and eosinophilic inclusion body formation. Polyphenol treatment ameliorated these effects by > or =67%. Survival was 30% after transplantation of small-for-size grafts. After polyphenol treatment, survival increased to 70%. Free radicals in bile assessed by spin trapping and 4-hydroxynonenal adducts measured by immunohistochemistry were also greater in reduced-size grafts, an effect ameliorated by polyphenols. Epicatechin, a major polyphenol from Camellia sinenesis, also improved graft function and decreased enzyme release, histopathologic changes, and free radical formation. CONCLUSIONS: Increased formation of free radicals occurs after transplantation of reduced-size livers, which contributes to graft dysfunction and failure. Plant polyphenols decrease liver graft injury and increase survival of small-for-size liver grafts, most likely by scavenging free radicals. Published 8 August 2005 in Gastroenterology, 129(2): 652-64.
© 2004-2008 Organ Transplantation Research Today. All Rights Reserved. |
| ||||||
