The role of leptin in the ventricular remodeling process and its mechanism.

Objective: This study aims to explore the role of leptin in the ventricular remodeling process and its mechanism in the diabetic rats' model.

Methods: The diabetic SD rats model induced by streptozotocin was established. The SD rats were randomly divided into 4 groups: control group (20 rats treated with citric acid/sodium citrate buffer); M0 group (10 rats treated with physiological saline); M1 group (10 rats treated with 50 μg/kg LP); M2 group (10 rats treated with 100 μg/kg LP). Ang-II was detected by ELISA. The expression levels of LP and Ob-Rb were detected by RT-PCR. MAPK phosphorylation changes were detected by western blotting. Myocardial morphology was observed.

Results: Compared with control group, the blood glucose concentration and Ang-II significantly increased in diabetic model groups (P < 0.01) and body weight decreased (P < 0.05). The expression levels of LP and Ob-Rb increased and heart function decreased in diabetic model groups.

Conclusions: LP may be involved in the myocardial cell hypertrophy through the neuroendocrine system and associated with the JAK-STAT, Ras-Raf-MEK-MAPK and PI-3K signaling pathway, which provides a new concept for the pathogenesis of cardiac hypertrophy.