to assess myocardial fibrosis were established according to histological analysis the changes in ventricular cavity of the mice perivascular fibrosis interstitial fibrosis and vacuole formation and other changes were taken into consideration to determine whether the model was useable experimental results as shown in table 5 it can be seen from the table that with the extension of time for modeling in myocardial tissue of the mice perivascular fibrosis interstitial fibrosis and vacuolization among tissue increased gradually and when the dose cumulated to 42 mg when making models namely after given 3 mg kg dox intraperitoneal injection twice a week in the seventh week the mice showed rather obvious myocardial fibrosis besides with this model making method mortality rate of the mice was relatively low so it was conducive to establish stable myocardial fibrosis model of the mice these results suggested that dox increased myocardial injury in mice and with the extension of time for modeling the severity increased the most appropriate dose for modeling was 42 mg namely twice a week 3 mg kg dox intraperitoneal injection for 7 weeks treating process the model making process was the same as embodiment 3 the models for groups b c d e f g and h were made with 3 mg kg dox and then as control groups groups a and b.