title: Heat shock preconditioning on mitochondria during warm ischemia in rat livers.
abstract: BACKGROUND
  The aim of this study was to investigate the effects of stress tolerance from heat shock preconditioning on changes in mitochondrial functions during ischemia-reperfusion injury of the liver.
  
  
  METHODS
  Rats were divided into a heat shock group (group HS) and a control group (group C). In group HS, rats received heat shock pretreatment 48 h prior to ischemia-reperfusion. Heat shock pretreatment was performed in a water bath at 42 degrees C for 15 min under general anesthesia. In group C, the same treatment was done with the water bath at 37 degrees C instead of at 42 degrees C. A 30-min warm ischemia by cramping the hepatoduodinal ligament (Pringle's maneuver) followed by a 60-min reperfusion was administered to all rats. Changes in membrane potential of hepatic mitochondria (MPM); mitochondrial respiratory function before ischemia (n = 5), after ischemia (n = 10), and after reperfusion (n = 10); and ATP recovery after reperfusion were compared between the groups.
  
  
  RESULTS
  After a 30-min ischemia, MPM in group C decreased significantly and did not recover even after reperfusion. On the other hand, MPM in group HS was maintained even after a 30-min ischemia and 60 min into reperfusion as well. The respiratory control ratio (RCR) of the mitochondria in group C decreased to as low as 5.06 +/- 0.72 after a 30-min ischemia, but in group HS, RCR was maintained near a normal level. The ATP level recovered significantly earlier in group HS than in group C after reperfusion.
  
  
  CONCLUSIONS
  Heat shock preconditioning of the liver protected mitochondria from loss of membrane integrity during ischemia and contributed to their ability to produce energy-rich phosphates during reperfusion.
authors.affiliation: Department of Gastroenterological Surgery, Kyoto University Graduate School of Medicine, Kyoto, 606-8507, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ishikawa
authors.forename: Y
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: M
authors.initials: M
authors.lastname: Kume
authors.forename: K
authors.initials: K
authors.lastname: Yamagami
authors.forename: H
authors.initials: H
authors.lastname: Yamamoto
authors.forename: S
authors.initials: S
authors.lastname: Kimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Sakai
authors.forename: M
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Yamaoka
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D006358:Hot Temperature; D007511:Ischemia / Q000503:physiopathology*; D019194:Ischemic Preconditioning; D008099:Liver / Q000098:blood supply*; D008297:Male; D008564:Membrane Potentials; D008930:Mitochondria, Liver / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species
chemical_list: D017382:Reactive Oxygen Species; D000255:Adenosine Triphosphate