Brain natriuretic peptide inhibits myocardial apoptosis caused by ischemia-reperfusion injury in rats in vivo

DENG Yu-jun; TAN Ning; ZENG Hong-ke; FU Yong-heng; DONG Xiao-li

摘要：Background This study aimed to investigate the effects of brain natriuretic peptide(BNP)on myocardial iscbemiareperfusion(I/R)injury in rats in vivo.Method Twenty-one,male,Spraguc-Dawley rats were randomly divided into three groups:(1)the sham operated group(SHAM)underwent thoraeotomy without ligation of the coronary artery;(2) in the I/R group,the left anterior descending coronary artery was ligated for 35 rain and then released to get reperfusion for 4 h;(3)in the BNP group,BNP was continuously infused 10 rain after the ligation at a rate of 0.01 μg/kg/min.Then the left anterior descending coronary artery was ligated for 35 min and released to get reperfusion for 4 h.The infusion of BNP was maintained until the end of reperfusion.The myocardial infarction area in each group was determined using the 1,2,3,5-triphenyhetrazolium staining method to measure the extent of myocardial I/R injury in rats.Myocardial apoptosis was detected using the terminal deoxynucleotidyl transferase mediated dUTP-biotin nick endlabeling(TUNEL)method.Results No myocardial infarction was observed in the SHAM group.The myocardial infarction size was 44.79±7.44% in the I/R injury group and 19.72±5.49% in the BNP group(P＜0.01).The apoptosis indices of the SHAM,BNP,and I/R groups were 5.37±4.21%,22.50±9.50%,and 45.24±13.01%,respectively(P＜0.01).Conclusions BNP can decrease the myocardial infarction size caused by I/R injury in rats in vivo.This finding may be accounted for by the fact that BNP decreases myocardial apoptosis induced by I/R injury.