Effects of rhBNP on the cardiac function and myocardial apoptosis of rats with myocardial infarction

Objective To assess the effects of recombinant human brain natriuretic peptide(rhBNP) on the cardiac function and myocardial apoptosis of rats with acute myocardial infarction(AMI).Methods AMI models were made in 100 SD rats by ligaturing the left coronary artery main stem of rats hearts.Then,the rats were divided into observed group and control group with 50 in each.Rats in observed group received rhBNP15ug/kg for 4 weeks.After treatment of 48 h,1 week,2 weeks,3 weeks and 4 weeks,left ventricular ejection fraction(LVEF) was detected by ultrasonography.Then the rats were executed,and the serum BNP level was examined,myocardial cell apoptosis index(MAI) was determinated by TUNEL and immunohistochemical detection of Fas/FasL protein positive staining index were analyzed as well.Results LVEF in observed group was significantly higher 48 h after the treatment,as compared with that in control group(P0.05).MAI in the observed group after the treatment of 3 and 4 weeks decreased significantly,compared with that of 48 h(P0.05) and which in control group 4 weeks after the treatment(P0.05).The positive rate of Fas/FasL protein in myocardium decreased significantly 2,3 and 4 weeks after the treatment,compared with that of 48 h(P0.05) and which in control group(P0.05).Conclusion rhBNP injected continuously for 4 weeks may efficiently improve the heart function of rats after myocardial infarction by inhibiting the cardiocyte apoptosis.