title: [Myocardial toll like receptor 4 expression in a rat model of myocardial ischemia reperfusion injury].
abstract: OBJECTIVE
  To explore the role of TLR4 in myocardial ischemia reperfusion injury (MI/RI) by observing the dynamic TLR4 expression changes at mRNA and protein levels early after myocardial ischemia reperfusion.
  
  
  METHODS
  Male SD rats were randomly divided into Sham and IR group and the rats were killed according to different reperfusion time (0, 0.5, 1, 2, 4 and 8 hours). Myocardial changes under light microscope and transmission electronic microscope were observed. TLR4 expressions at protein and mRNA levels were detected by immunohistochemistry and realtime RT-PCR respectively. Myocardial TNF-alpha was determined by ELISA.
  
  
  RESULTS
  (1) Myocardial injury was observed in IR but not in Sham group and histopathological and ultrastructural changes in IR group remained unchanged up to 8 hours after reperfusion. (2) Positive TLR4 protein staining was visualized in both Sham and IR groups and significantly increased and peaked at 1 hour of reperfusion in IR group. (3) Compared to Sham group, TLR4 mRNA level was upregulated in myocardium in IR group and peaked at 1 hour of reperfusion. (4) Concentration of TNF-alpha in IR group was significantly higher than that of Sham group at corresponding time points (all P < 0.05), and myocardial TLR4 mRNA level correlated positively with myocardial TNF-alpha (r = 0.728, P < 0.01).
  
  
  CONCLUSIONS
  Expression of TLR4 in myocardium during early after myocardial ischemia reperfusion was upregulated and actived TLR4 might play an important role in MI/RI through promoting myocardial TNF-alpha excretion.
authors.affiliation: The Department of Cardiology, Yichang Central People's Hospital and The First College of Clinical Medical Science, China Three Gorges University, Yichang 443003, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Jia-Wang
authors.initials: JW
authors.lastname: Ding
authors.forename: Zu-Yang
authors.initials: ZY
authors.lastname: Xi
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Li
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.forename: Yan-Lin
authors.initials: YL
authors.lastname: Wang
authors.forename: Ya-Qin
authors.initials: YQ
authors.lastname: Wang
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000378:metabolism* / Q000473:pathology; D009206:Myocardium / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D051197:Toll-Like Receptor 4 / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha