Abstract 8264: Exercise Training Improves Cardiac Function and Restores Nuclear Localization of pAKT in Aged Mice
Cardiovascular aging is frequently associated with atherosclerosis, hypertension, and vascular stiffening as well as significant functional and molecular changes that result in cardiac hypertrophy and the development of fibrosis. On a functional scale, aerobic exercise is known to induce physiologic hypertrophy and to improve cardiovascular performance. In this study we sought to determine the effectiveness of exercise in aged (24-26 month old) C57/BL6 mice as well as to explore potential mechanisms for any observed cardiovascular improvement. Old and young mice underwent exercise training by swimming for a period of six weeks. At the conclusion of the swim training, hemodynamic and molecular markers of cardiac function in old and young mice were assessed. We show that exercise training results in significant improvement in left ventricular (LV) function in older animals, a significant increase in ejection fraction (EF) and mean stroke work index (MSWI), and an improvement in the time constant of LV relaxation (Tau). Swim training also resulted in a reduction in aging-associated oxidative stress (42 +/-13% reduction in luminol activity when compared to old sedentary, P<0.05). In addition, aging was associated with a significant shift of pAKT from the nucleus to the cytosol and exercise training reversed this process. These findings demonstrate that swimming not only has a beneficial effect on cardiac function in the aged, but can also serve to mediate and even reverse the biological processes associated with age-related cardiovascular changes in the elderly.
- © 2011 by American Heart Association, Inc.