Effects of erythropoietin on matrix remodeling and the expressions of MMPs and TIMP-4 after myocardial infarction in rats / 解放军医学杂志

ABSTRACT

Objective To investigate the effects of erythropoietin(EPO) on extracellular matrix remodeling and the expressions of matrix metalloproteinase(MMPs) and tissue inhibitor of metalloproteinase-4(TIMP-4) after myocardial infarction in rats.Methods Eighty male SD rats were randomly divided into four groupssham operation(SH) group,sham operation and drug(SHE) group,myocardial infarction(MI) group,and myocardial inferct and erythropoietin(MIE) group.Myocardial infarction in MI group and MIE group was reproduced by ligation of a branch of left anterior descending coronary artery.Hematocrit,echocardiography,capillary density,infarct area,fibrosis and collagen volume fraction were tested,and MMP-2,MMP-9 and TIMP-4 were measured by immunohistochemistry at 1-week and 6-week after myocardial infraction.Results One week after myocardial infraction,the protein expressions of MMP-2 and MMP-9 in MI and MIE groups were significantly higher than that in SH and SHE group(P0.05).Six weeks after myocardial infraction,echocardiography revealed that the left ventricular end-diastolic dimension(LVDd),left ventricular end-systolic dimension(LVDs),left ventricular end-diastolic volume(LVEDV) and left ventricular end-systolic volume(LVESV) were significantly increased,and left ventricular ejection fraction(LVEF) and left ventricular fractional shortening(LVFS) were significantly decreased in MI and MIE groups compared with those in SH and SHE groups(P