[Study of the effect of p53 and Bcl-2 protein expression in myocardial apoptosis in septic rats].
OBJECTIVE
To explore the significance of p53 and Bcl-2 gene in myocardial apoptosis in septic rats.


METHODS
Adult male Sprague-Dawley (SD) rats were randomly divided into normal control group (n=6), sham operation group (n=6) and cecal ligation and puncture (CLP) group (n=24). The sepsis model was reproduced by CLP. Rats in CLP group were divided into four subgroups according to the time points of 3, 9, 12, and 24 hours after operation, with 6 rats in each subgroup, and their hearts were examined according to the experimental protocol. Myocardial apoptosis was detected with electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) technique. Bcl-2 and p53 protein expression was measured by immunohistochemistry method.


RESULTS
Myocardial apoptosis index (AI) in septic rats were increased, higher than that in normal control group [(1.500+/- 0.141)%] and sham operation group [(1.567+/-0.258)%, all P<0.05]. The myocardial AI peaked at 12 hours [(55.633+/-2.073)%], and lowered at 24 hours [(33.683+/-2.070)å]. The expression level of p53 protein in CLP group was lowest at 3 hours [(13.817+/-0.964)%], peaked at 12 hours [(80.567+/-5.055)%], and higher than that in normal control group [(0.617+/-0.232)%] and sham operation group [(0.600+/-0.297)%, all P<0.05 ]. The trend was parallel with that of the results of TUNEL. However, the expression level of Bcl-2 protein peaked at 3 hours [(31.650+/-1.799)%], and was lowest at 12 hours [(0.650+/-0.308)%], and lower than that in normal control group [(47.017+/-0.691)%] and sham operation group [(46.817+/-0.567)%, all P<0.05]. The trend was opposite with that of the results of TUNEL.


CONCLUSIONS
Myocardial apoptosis may be a mechanism of the pathogenesis of myocardial injury in sepsis. The change in the modulating genes p53 and Bcl-2 of apoptosis may serve as indicators of myocardial injury. p53 and Bcl-2 gene may be used as an interventional means in sepsis to change its outcome.
Zhai
Cheng-Shun
CS
Medical Department, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, Guangdong, China.
Tang
Hao
H
Liang
Yan-Bing
YB
Chen
Zhi-Bin
ZB
Li
Zhen-Yu
ZY
Ma
Zhong-Fu
ZF
D000818:Animals; D017209:Apoptosis; D004195:Disease Models, Animal; D008297:Male; D009206:Myocardium / Q000378:metabolism / Q000473:pathology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D018805:Sepsis / Q000378:metabolism / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53