title: [Role of stress in myocardial protection of ischemic preconditioning].
abstract: OBJECTIVE
  To determine the role of stress in myocardial protection of ischemic preconditioning (IPC).
  
  
  METHODS
  Thirty rabbits were randomly divided into an IPC group, an etomidate (Etom) group, an ischemic/reperfusion (IR) group, a methylprednisolone (MP) group and a sham group. The ratio of infarction size versus risk area (infarct/risk) was calculated. The elevations of the serum creatine kinase (CK) activity and cardiac troponin I (cTnI) concentrations as well as the serum cortisol concentrations were measured.
  
  
  RESULTS
  The percentages of infarct/risk in the IPC group, the MP group, the IR group, and the Etom group were (5.86±2.81)%, (11.28±3.62)%, (26.79±4.53)%, and (18.19±3.72)%, respectively. The elevations of the serum CK activity in the IPC group, the MP group, the IR group, and the Etom group were (255±89), (314±160), (855±371), and (768±404) U/L, respectively. The elevations of serum cTnI concentrations in the IPC group, the MP group, the IR group, and the Etom group were (3.6±0.6),(6.1±2.2), (8.1±3.6), and (6.4±1.6) μg/L, respectively. Those indicators among the groups were significantly different (P<0.05). Cortisol reaction was markedly diminished in the Etom group.
  
  
  CONCLUSIONS
  A blunted cortisol reaction can markedly reduce the benefit of IPC while methylprednisolone shows cardioprotective effects, suggesting that stress might be involved in the myocardial protection of IPC.
authors: Department of Cardiovascular Surgery, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052; Department of Cardiothoracic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China.
authors: Huashan
authors: H
authors: Xu
authors: Shengxi
authors: S
authors: Chen
authors: Wanjun
authors: W
authors: Luo
authors: Haihe
authors: H
authors: Jiang
mesh_terms: D000818:Animals; D005045:Etomidate / Q000494:pharmacology; D005260:Female; D006854:Hydrocortisone / Q000097:blood; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D009203:Myocardial Infarction / Q000503:physiopathology*; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D011817:Rabbits; D013312:Stress, Physiological
chemical_list: D006854:Hydrocortisone; D005045:Etomidate