Abstract: Objective To establish a rat model of cardiac insufficiency complicated with diabetes mellitus (DM), and to meet the needs of clinical and laboratory studies. Methods Forty-five male specific pathogen free (SPF) rats were randomly divided into three groups: normal control group (A, n=10 ), coarctation of the aorta (AAC) group (B, n=10), AAC+DM group (C, n=25). The model of cardiac insufficiency with abdominal aortic constriction was establish in B and C groups. After two months of AAC, rats of group C were randomly divided into five subgroups and treated with different doses of streptozotocin (STZ) respectively(40, 45, 50, 55 and 60 mg/kg). The dynamic changes of general condition and weights were observed during the process of experiment. The blood glucose levels of 72 h and 4 week after STZ injection were detected. The echocardiograph and cardiac pathology changes were evaluated after 1 month of STZ injection. Results The general data including blood glucose levels, echocardiographic findings and myocardial tissue microscopic morphology were compared be⁃tween different doses of STZ groups. The 45 mg/kg STZ was considered for more stable model of cardiac dysfunction complicated with diabetes mellitus. Conclusion The rat model of cardiac insufficiency complicated with diabetes mellitus is established by single dose injection of 45 mg/kg STZ after two-month AAC, which is a simple, reliable and high stability method.

Key words: cardiac insufficiency, diabetes mellitus,experimental, abdominal aortic constriction, disease models, animal, rats, Wistar