title: Liver injury after intermittent or continuous hepatic pedicle clamping and its protection by reduced glutathione.
abstract: BACKGROUND
  The debate is still going on about selection of several clamping patterns during hepatectomy. The aim of this study was to assess the safety and preference of normothermic intermittent or continuous hepatic pedicle clamping and confirm the protective effect of reduced glutathione (GSH).
  
  
  METHODS
  Thirty-two adult male healthy Sprague-Dawley (SD) rats were divided into groups of intermittent clamping and GSH absent (IA), continuous clamping and GSH absent (CA), intermittent clamping and GSH present (IP) and continuous clamping and GSH present (CP). The clamping manners were successively 40 minutes in continuous clamping groups and two cycles of 20 minutes with an interval of 5 minutes in intermittent clamping groups, and reperfusion periods were 60 minutes. Experimental parameters included levels of malonaldehyde (MDA) and Cu/Zn superoxide dismutase (SOD), pathological and ultrastructural changes in liver tissues, activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in sera.
  
  
  RESULTS
  In the same group, the activities of ALT and AST were significantly higher in post-clamping rats than in pre-clamping rats (P<0.05), but no significant differences were noted in levels of MDA and Cu/Zn SOD (P>0.05). The differences of all values between post-reperfusion rats and pre-clamping rats were significant (P<0.05). Pathological and ultrastructural changes could be observed, but no irreversible injury was present. The comparison of the groups showed that the values at relevant time points between the intermittent and continuous groups were not significantly different (P>0.05). The values were significantly different between the GSH absent and present groups after reperfusion (P<0.05). The morphological damages were also obviously alleviated in the GSH present group.
  
  
  CONCLUSIONS
  Normothermic intermittent or continuous hepatic pedicle clamping could cause reversible liver ischemia/reperfusion injury when the clamping time lasts 40 minutes. The injury extent seems to be similar. Continuous clamping should be regarded as a proper method in liver surgery. GSH has been confirmed as an effective agent in preventing post-clamping liver injury.
authors.affiliation: Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100032, China. lizhou02@hotmail.com
authors.forename: Li
authors.initials: L
authors.lastname: Zhou
authors.forename: Jing-An
authors.initials: JA
authors.lastname: Rui
authors.forename: Rou-Li
authors.initials: RL
authors.lastname: Zhou
authors.forename: Xue-Min
authors.initials: XM
authors.lastname: Peng
authors.forename: Shao-Bin
authors.initials: SB
authors.lastname: Wang
authors.forename: Shu-Guang
authors.initials: SG
authors.lastname: Chen
authors.forename: Qiang
authors.initials: Q
authors.lastname: Qu
authors.forename: Yu-Pei
authors.initials: YP
authors.lastname: Zhao
mesh_terms: D000818:Animals; D003250:Constriction; D005978:Glutathione / Q000008:administration & dosage*; D006498:Hepatectomy / Q000009:adverse effects / Q000379:methods*; D008099:Liver / Q000098:blood supply* / Q000601:surgery; D008102:Liver Circulation / Q000502:physiology; D008107:Liver Diseases / Q000503:physiopathology / Q000517:prevention & control*; D008297:Male; D023421:Models, Animal; D011506:Proteins / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000503:physiopathology / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D011506:Proteins; D005978:Glutathione