title: [Effect of naloxone on expression of Bcl-2 protein and tumor necrosis factor-alpha in rats with acute myocardial ischemia/reperfusion injury].
abstract: OBJECTIVE
  To investigate the effect of naloxone on myocardial cell apoptosis and apoptosis-related gene Bcl-2 in rats with acute myocardial ischemia/reperfusion (AMIR) injury, and explore the mechanism of protective effect of naloxone on myocardium.
  
  
  METHODS
  Thirty SD rats were randomly divided into three groups (n=10): ischemia/reperfusion group, naloxone preconditioning group (naloxone was injected intraperitoneally 10 minutes before ischemia and 2 hours after reperfusion), and normal control group. The left anterior descending branch (LAD) of rat coronary artery was tied and un-tied in ischemia/reperfusion group and naloxone preconditioning group to establish the AMIR model in rats. The animals were then sacrificed and hearts were harvested. The expression of Bcl-2 protein was observed by immunohistochemical technique. Radioimmunoassay (RIA) was used to determine tumor necrosis factor-alpha (TNF-alpha) in serum.
  
  
  RESULTS
  In the normal control group, there was no Bcl-2 expression and TNF-alpha level was (0.39+/-0.06) mug/L. Higher expression of Bcl-2 and increased TNF-alpha levels were found in ischemia/reperfusion group. The expression of Bcl-2 protein increased significantly [(+++) vs. (+)], and TNF-alpha was significantly lower in naloxone preconditioning group than those in the normal control group [(0.55+/-0.12) microg/L vs. (0.86+/-0.11) microg/L, P<0.01].
  
  
  CONCLUSIONS
  Naloxone can protect myocardium from AMIR injury by inhibiting the apoptosis of cardiomyocytes induced by TNF-alpha and up-regulating protein expression of bcl-2 gene.
authors: Department of Anatomy, Lanzhou Medical College, Lanzhou 730000, Gansu, China. tangxq@lzu.ed.cn
authors: Xiao-qin
authors: XQ
authors: Tang
authors: Jian-hong
authors: JH
authors: Zhao
authors: Zheng-yi
authors: ZY
authors: Zhang
authors: Xu
authors: X
authors: Zhang
authors: Shao-li
authors: SL
authors: Song
mesh_terms: D000818:Animals; D017209:Apoptosis; D004195:Disease Models, Animal; D015428:Myocardial Reperfusion Injury / Q000378:metabolism* / Q000473:pathology; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D009270:Naloxone / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D014409:Tumor Necrosis Factor-alpha; D009270:Naloxone