title: The cardioprotective effect of hypoxic and ischemic preconditioning in dogs with myocardial ischemia-reperfusion injury using a double-bypass model.
abstract: OBJECTIVE
  The effects of preconditioning on cardioprotection have mainly been studied in vitro. No sufficient in vivo experiments have been performed to optimize ischemic preconditioning (IPC) or hypoxic preconditioning (HPC) for clinical applications. The purpose of this study was to establish a canine double-bypass model to examine the effect of IPC and HPC on cardiomyocytes and heart function.
  
  
  METHODS
  A double-bypass procedure to enable independent control of systemic and coronary circulation was established in dogs. The animals were divided into control, HPC, and IPC groups (n=6 each). Indicators of cardiac function, including cardiodynamics, hemodynamics, ATP, and cardiac troponin I (cTnI) levels; myocardium morphology; and myocardiocyte apoptosis were determined.
  
  
  RESULTS
  Both IPC and HPC attenuated the reperfusion-induced decrease in left ventricular end systolic pressure seen in the control group. Both the HPC and IPC groups had lower serum cTnI levels, better myocardiocyte histology, and lower rates of apoptosis compared to the control group without preconditioning. HPC reduced the abnormal cardiomyocyte histology and apoptosis to a greater extent than IPC, and only HPC significantly restored the depletion of ATP.
  
  
  CONCLUSIONS
  This study demonstrates the effectiveness of the double-bypass model for the optimized study of both HPC and IPC. The results suggest that HPC may provide better cardioprotection than IPC.
authors.affiliation: Department of Anesthesiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, China.
authors.forename: Chun-Ling
authors.initials: CL
authors.lastname: Chen
authors.affiliation: Department of Anesthesiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, China. Electronic address: xjzhenghong@aliyun.com.
authors.forename: Hong
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Department of Anesthesiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xuan
authors.affiliation: Department of Anesthesiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, China.
authors.forename: Ablikim
authors.initials: A
authors.lastname: Amat
authors.affiliation: Department of Anesthesiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Anesthesiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Anesthesiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Wang
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001794:Blood Pressure; D003326:Coronary Circulation; D004285:Dogs; D005260:Female; D006334:Heart Function Tests; D006439:Hemodynamics; D000860:Hypoxia / Q000503:physiopathology*; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods*; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D032383:Myocytes, Cardiac / Q000473:pathology / Q000648:ultrastructure; D013318:Stroke Volume / Q000187:drug effects; D019210:Troponin I / Q000378:metabolism
chemical_list: D019210:Troponin I; D000255:Adenosine Triphosphate
keywords: Apoptosis; Cardiopulmonary bypass (CPB); Hypoxia preconditioning (heart); Ischemia/reperfusion injury; Myocardial injury