Effect Of Midkine Combined Losartan On Remodeling Of Infarct Zone Of Rats After Acute Myocardial Infarction

Objective:To explore the effect of the Midkine and Losartan to the remodeling processes of ventricie on the rat model of acute myocardial (AMI) infarction.Methods and methods:60 female Wistar rats were randomly divided into so operation group (SO group, n= 15),acute myocardial infarction group (MI group, n= 15), midkine group (MI+ MK group, n= 15) and midkine+Losartan (MI+MK+LOS groups, n=15). In MI group,MI+MDK group and MI+MK+LOS group Ligated the left anterior descending coronary artery in order to make acute myocardial infarction model, in Pseudo-operation group Only winds thread does not tie up。After making the mold success, each rat was immediately treated by injecting doses of 1ug/200g recombinant human Midkine into the border zone myocardium at five sites after the ligation succeed. The rat of MI+MK+LOS group has been filled the stomach whith Losartan (15mg/kg) daily. After 4 weeks we survey the following indicatrix:1. haemodynamics :left ventricular systolic pressure(LVSP), left ventricular diastolic pressure(LVDP), left ventricular end diastolic pressure;left ventricular end-diastolic pressure(LVEDP), Maximum left ventricular pressure rise and fall speed in isovolumic contraction period(±dp/dt max);2. heart muscle fibrosis:collagen volume fraction in Infarct area and non-infarct area(CVF);3. cardiac enlargement: The left ventricular absolute weight(LVAW). The right ventricular absolute weight(RVAW). The left ventricular relative weight (LVRW). The right ventricular relative weight(RVRW);4. Micromodule freshman and infarction area: Density of the blood vessel, Thickness of the infarction wall, Length of the infarction wall, infarct size, non-Infarct size in the cardiac muscle.Result: intragastric administration 4 weeks, MI + MK group Compare with Infarct group; MI+MK+LOS group Compare with MI + MK group; Front one, The rat cardiac muscle infarction covers an area of without exception notable diminution(P<0.01); Retinue heart chamber weight is notable ease off(P<0.01); new vessels increase obviously surround infarct area(P<0.01);Notable left ventricle function have been improvement(P<0.01); Collagen volume in infarction area is fractional notable increase obviously(P<0.01); Collagen volume in non-infarction area is fractional notable decrease obviously(P<0.01).Conclusion:The result studying indicates capital, The heart chamber ventricular remodeling afte acute myocardial infarction behaviour like the heart function descends, heart muscle fibrosis, cardiac enlargement and Infarction area increasing.The transplantation of MK can promote angiogenesis, improve the cardiac function, prevent the remodeling process of the left ventricle and reduce the infarctsize, and further benefits can be obtained by co-administration of Losartan Significantly.