Abstract: Objective To study the of mechanism of adriamycin induced myocardial fibrosis .Methods Construct rat model of doxorubicin induced myocardial fibrosis. Detect the myocardial pathological changes with HE and Masson staining, and detect the expression level of fibrosis related gene Col1α, Col3α, TGF-β1 with RT-qPCR and immunohistochemistry. The immunofluorescence technique was used to detect the expression of the marker of vascular endothelial cell (vWF) and mesenchymal cell (α-SMA). Results Enlargement of ventricular cavity, thinning of heart wall, widening of myocardial fiber space, myocardial dissolving and fibrosis, myocardial vascular endothelial injury and permeability increase happened in rats with intraperitoneal injection of adriamycin. With the prolonged action of adriamycin, the expression of myocardial fibrosis factors and fibrosis related factors Col1α、Col3α、TGF-β1 increased, endothelial cell transformation happened in cardiac vascular endothelial cells. Conclusion Adriamycin can induce irreversible myocardial fibrosis in rats, and endothelium transformation is involved in the formation of doxorubicin induced myocardial fibrosis.

Key words: Endothelial to Mesenchymal Transition（EndoMT）, Cardiac fibrosis, TNF-α, TGFβ,α-SMA