Abstract: Objective:To observe the changes of YAP,the effector protein of Hippo pathway,in rat model with myocardial hypertrophy induced by diabetes,and analyze its possible mechanism.Methods:Twelve healthy male SD rats were randomly divided into the normal control group and diabetic cardiomyopathy group(6 rats each group).The normal control group was fed with normal water and diet for 12 weeks,the diabetes model with blood glucose level ≥ 16.7 mmo1/L for 1 week was established successfully by intraperitoneal injection of STZ(55 mg/kg),and fed for 12 weeks.In two groups,the fasting blood glucose level and body weight were measured,the left ventricle dynamics was detected through intraventricular intubation,and the ratio of heart to body weight was calculated by weighing heart.The expression levels of cardiac hypertrophy related gene atrial natriuretic factor(ANF) and brain natriuretic peptide(BNP) mRNA were detected using fluorescence quantitative PCR,and the expression levels of YAP and p-YAP protein level were detected using Western blot.Results:Compared with the normal control group,the ratio of heart to body increased,the left ventricular end-diastolic blood pressure increased,the rate of rise and fall of the maximum left ventricular development pressure decreased,and the left ventricular doing work decreased in diabetic cardiomyopathy group.The expression levels of ANF and BNP mRNA increased,the YAP protein expression increased and the ratio of p-YAP/YAP decreased.Conclusions:Diabetes can induce myocardial hypertrophy,the mechanism of which may be related to the increasing of YAP protein expression in Hippo signaling pathway to decrease of the phosphorylation level.