title: Remote Ischemic Preconditioning Enhances the Expression of Genes Encoding Antioxidant Enzymes and Endoplasmic Reticulum Stress-Related Proteins in Rat Skeletal Muscle.
abstract: OBJECTIVE
  Ischemic preconditioning (IPC), including remote IPC (rIPC) and direct IPC (dIPC), is a promising method to decrease ischemia-reperfusion (IR) injury. This study tested the effect of both rIPC and dIPC on the genes for antioxidant enzymes and endoplasmic reticulum (ER) stress-related proteins.
  
  
  METHODS
  Twenty rats were randomly divided into the control and study groups. In the control group (n=10), the right hind limb was sham-operated. The left hind limb (IscR) of the control group underwent IR injury without IPC. In the study group (n=10), the right hind limb received IR injury after 3 cycles of rIPC. The IscR received IR injury after 3 cycles of dIPC. Gene expression was analyzed by Quantitative real-time polymerase chain reaction from the anterior tibialis muscle.
  
  
  RESULTS
  The expression of the antioxidant enzyme genes including glutathione peroxidase (GPx), superoxide dismutase (SOD) 1 and catalase (CAT) were significantly reduced in IscR compared with sham treatment. In comparison with IscR, rIPC enhanced the expression of GPx, SOD2, and CAT genes. dIPC enhanced the expression of SOD2 and CAT genes. The expression of SOD2 genes was consistently higher in rIPC than in dIPC, but the difference was only significant for SOD2. The expression of genes for ER stress-related proteins tended to be reduced in IscR in comparison with sham treatment. However, the difference was only significant for C/EBP homologous protein (CHOP). In comparison with IscR, rIPC significantly up-regulated activating transcription factor 4 and CHOP, whereas dIPC up-regulated CHOP.
  
  
  CONCLUSIONS
  Both rIPC and dIPC enhanced expression of genes for antioxidant enzymes and ER stress-related proteins.
authors.affiliation: Department of Surgery, Keimyung University School of Medicine, Daegu, Ulsan, Korea.
authors.forename: Ui Jun
authors.initials: UJ
authors.lastname: Park
authors.affiliation: Department of Surgery, Keimyung University School of Medicine, Daegu, Ulsan, Korea.
authors.forename: Hyoung Tae
authors.initials: HT
authors.lastname: Kim
authors.affiliation: Department of Surgery, Keimyung University School of Medicine, Daegu, Ulsan, Korea.
authors.forename: Won Hyun
authors.initials: WH
authors.lastname: Cho
authors.affiliation: Department of Physiology, Keimyung University School of Medicine, Daegu, Ulsan, Korea.
authors.forename: Jae Hyoung
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Pathology, Keimyung University School of Medicine, Daegu, Ulsan, Korea.
authors.forename: Hye Ra
authors.initials: HR
authors.lastname: Jung
authors.affiliation: Department of Nursing, University of Ulsan, Ulsan, Korea.
authors.forename: Min Young
authors.initials: MY
authors.lastname: Kim
keywords: Ischemic preconditioning; Muscle; Reperfusion injury; Skeletal