The Effect of Resistance Training on PI۳K/mTORc۱ Signaling in Left Ventricle of Diabetic Rats

Background: Clinical evidence supports the influential role of genetic factors and intracellular signaling pathways in physiological cardiac hypertrophy. This study aimed to assess the response of the PI۳K/mTORc۱ signaling pathway in cardiac tissue to resistance training in obese rats with Type ۲ Diabetes (T۲D). Materials and Methods: A total of ۲۱ male Wistar rats (Mean±SD weight: ۲۲۰±۲۰ g) were obese by ۶ weeks High-Fat Diet (HFD) and randomly assigned to ۱) non-diabetic, ۲) control T۲D, and ۳) exercise diabetic groups. T۲D was induced by intraperitoneal injection of streptozotocin (۳۰ mg/kg) for diabetic groups. The exercise group did the resistance exercise program (۵ times per week for ۶ weeks). After exercise training, PI۳K and mTORc۱ expression in the left ventricle and the ratio of the left ventricle to heart and heart to body weight were compared between groups. The obtained data were compared by ۱-way Analysis of Variance (ANOVA) (P<۰.۰۵). Results: Induction of diabetes resulted in significant decrease in all mentioned variables in control diabetic to non-diabetic rats (PI۳K; P=۰.۰۲۱, mTORc۱; P=۰.۰۰۴, left ventricle/heart weight; P=۰.۰۴۵, heart/body weight; P=۰.۰۳۵). Significant increase was observed in all variables (PI۳K; P=۰.۰۲۸, mTORc۱; P=۰.۰۱۵, left ventricular/heart weight; P=۰.۰۰۲, heart/body weight; P=۰.۰۰۱) in response to resistance training compared to the control rat. Conclusion: Based on our results, cardiac hypertrophy in studied diabetic rats can be attributed to improved PI۳K/mTORc۱ signaling in response to resistance training. Exploring the exact mechanisms responsible for these changes in response to exercise requires further molecular-cellular studies.

Keywords:

Heart Hypertrophy , Exercise , Gene’s expression , Diabetes