title: Rho-kinase inhibition is involved in the activation of PI3-kinase/Akt during ischemic-preconditioning-induced cardiomyocyte apoptosis.
abstract: We and others have reported that Rho-kinase plays an important role in the pathogenesis of heart ischemia/reperfusion (I/R) injury. Studies also have demonstrated that the activation of Rho-kinase was reversed in ischemic preconditioning (IPC). This study aimed to explain the mechanism of Rho-kinase-mediated cardiomyocyte apoptosis increased in I/R and reversed in IPC.
  
  
  METHODS
  Studies were performed with female Wistar rats. The I/R rats were created by ligating the left anterior descending branch (LAD) for 30 min and releasing the ligature for 180 min. The IPC rats underwent IPC (two cycles of 5 min ligation of the LAD and 5 min reflow) before I/R.
  
  
  RESULTS
  Ischemia followed by reperfusion caused a significant increase in Rho-kinase and a decrease in Akt phosphorylation. Administration of fasudil, an inhibitor of Rho-kinase, decreased myocardial infarction size and cardiomyocyte apoptosis and increased Akt activation. IPC also caused the reduced Rho-kinase activity and cardiomyocyte apoptosis and a significant increase in Akt activity (P<0.05 vs I/R).
  
  
  CONCLUSIONS
  Rho-kinase inhibition by IPC leads to reduced cardiomyocyte apoptosis may be mediated by activation of PI3-kinase/Akt.
authors.affiliation: Department of Cardiology, The Second Hospital of Shandong University Jinan, Shandong Province, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Shandong Blood Center Jinan, Shandong Province, China.
authors.forename: Xiao-Bo
authors.initials: XB
authors.lastname: Liu
authors.affiliation: Department of Cardiology, The Second Hospital of Shandong University Jinan, Shandong Province, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Cheng
authors.affiliation: Department of Cardiology, The Second Hospital of Shandong University Jinan, Shandong Province, China.
authors.forename: Dong-Ling
authors.initials: DL
authors.lastname: Xu
authors.affiliation: Department of Cardiology, The Second Hospital of Shandong University Jinan, Shandong Province, China.
authors.forename: Qing-Hua
authors.initials: QH
authors.lastname: Lu
authors.affiliation: The Key Laboratory of Cardiovascular Remodeling and Function Research of Chinese Ministry of Education and Public Health, Shandong University Qilu Hospital Jinan, Shandong Province, China.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Ji
keywords: PI3-kinase/Akt; Rho-kinase; apoptosis; heart ischemia/reperfusion; ischemic preconditioning