Abstract: AIM: To investigate the changes of mitofusin 2 (Mfn2) on myocardial injury in diabetic rats. METHODS: Diabetic rat model was simulated by intraperitoneal injection 55 mg/kg streptozotocin and divided into normal group, diabetes at 4th week (DM 4W), and diabetes at 8th week (DM 8W) groups. The ventricular hemodynamical parameters in vitro and heart weight/body weight (HW/BW) were determined. The level of CK-MB in serum was determined by automatic biochemistry analyzer. Mfn2 mRNA expression of left anterior myocardium was evaluated by RT-PCR. RESULTS: In contrast to normal rat, left ventricular developed pressure (LVDP), maximal rise/fall rate of left ventricular pressure (±dp/dt_max), heart rate (HR), left ventricular work (RPP) and CK-MB level were decreased in DM 4W and DM 8W rats (P<0.05, P<0.01), left ventricular end diastolic pressure (LVEDP) and HW/BW were increased (P<0.01), and the expression of Mfn2 mRNA was decreased (P<0.01); compared with DM 4W rat, LVDP, ±dp/dt_max, HR, RPP and CK-MB level were further decreased in DM 8W rat (P<0.05, P<0.01), LVEDP and HW/BW were increased (P<0.01), and the expression of Mfn2 mRNA was further decreased (P<0.01). CONCLUSION: With the development of diabetes, ventricular function was decreased further, it is maybe related to the decrease of Mfn2 mRNA expression.

Key words: Diabetes mellitus, Heart, Mitofusin 2, Creatine kinase isozyme