earticle

영어

Aging is a significant risk factor for cardiovascular diseases and plays a critical role in the pathologic mechanisms of cardiac failure or diseases. A characteristic of the typical physiological change of cardiac muscle by aging is the reduction of heart function due to reactive hypertrophy. The purpose of this study was to determine whether aerobic exercise training attenuates aging-induced hypertrophy signaling in the rat heart. Fischer 344 rats were divided into young sedentary (YS; n=10, 4 months) group, young exercise (YE; n=10, 4months) group, old sedentary (OS; n=10, 20 months) group, and old exercise (OE; n=10, 20 months) group. Exercise training groups ran on a treadmill at 15 m/min (young) or 10 m/min (old), 45 min/day, 5 days/week for 8 weeks. Left ventricle was extracted to determine the protein levels of Akt/mTOR signaling pathway (Akt, mTOR, p70s6k, and 4E-BP1) through Western immunoblot analysis. The protein levels of Akt/mTOR signaling were not significantly increased in the OS compared with YS. However, Akt/mTOR signaling levels were significantly increased by exercise training. The data demonstrated that aerobic exercise training activated the Akt/mTOR signaling pathway of rat heart, suggesting that aerobic exercise training may induce muscle growth in left ventricle, leading to cardiac muscle hypertrophy in rats.