Myocardial Toll like receptor 4 expression in a rat model of myocardial ischemia reperfusion injury
10.3321/j.issn:0253-3758.2008.01.014
- VernacularTitle:Toll样受体4在大鼠心肌缺血再灌注损伤中表达的实验研究
- Author:
Jian YANG
1
;
Jun YANG
;
Jia-Wang DING
;
Zu-Yang XI
;
Wen-Hui LI
;
Song LI
;
Yong CHEN
;
Yan-Lin WANG
;
Ya-Qin WANG
Author Information
1. 三峡大学第一临床医学院(宜昌市中心人民医院)
- Keywords:
Myocardial ischemia;
Reperfusion injury;
Toll like receptor 4;
Tumor necrosis factor-α
- From:
Chinese Journal of Cardiology
2008;36(1):57-61
- CountryChina
- Language:Chinese
-
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-α was determined by ELISA.Results (1)Myocardial injury was observed in IR but not in Sham group and histopathological and uhrastructual 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-α 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-α (r=0.728,P＜0.01).Conclusion Expression of TLR4 in myocardium during early after myocardial ischemia repeffusion was upregulated and actived TLR4 might play an important role in MI/RI through promoting myocardial TNF-α excretion.
