Habitual exercise program protects murine intestinal, skeletal, and cardiac muscles against aging

• Published in: Journal of applied physiology (1985) 2005-10, Vol.99 (4), p.1569-1575
• Main Authors: Rosa, Eloi F, Silva, Antonio C, Ihara, Silvia S. M, Mora, Oswaldo A, Aboulafia, Jeannine, Nouailhetas, Viviane L. A
• Format: Article
• Language: English
• Subjects: Aging; Aging - physiology; Animals; Biological and medical sciences; Body Weight; Carbachol - pharmacology; Exercise; Fundamental and applied biological sciences. Psychology; Heart - anatomy & histology; Ileum - cytology; Ileum - drug effects; Ileum - metabolism; Ileum - ultrastructure; Intestines - physiology; Lipid Peroxidation; Lipids; Male; Mice; Mice, Inbred C57BL; Muscarinic Agonists - pharmacology; Muscle, Skeletal - anatomy & histology; Muscle, Skeletal - metabolism; Muscle, Skeletal - physiology; Muscle, Smooth - physiology; Myocardium - metabolism; Organ Size; Oxidation; Papillary Muscles - physiology; Physical Conditioning, Animal - physiology; Potassium Chloride - pharmacology
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00417.2005

Departments of 1 Biophysics, 2 Physiology, 3 Pathology, and 4 Morphology, Universidade Federal de São Paulo/Escola Paulista de Medicina, São Paulo, Brazil Submitted 14 April 2005 ; accepted in final form 14 June 2005 ABSTRACT Aging and aerobic exercise are two conditions known to interfere with health and quality of life, most likely by inducing oxidative stress to the organism. We studied the effects of aging on the morphological and functional properties of skeletal, cardiac, and intestinal muscles and their corresponding oxidative status in C57BL/6 mice and investigated whether a lifelong moderate exercise program would exert a protective effect against some deleterious effects of aging. As expected, aged animals presented a significant reduction of physical performance, accompanied by a decrease of gastrocnemius cross-sectional area and cardiac hypertrophy. However, most interesting was that aging dramatically interfered with the intestinal structure, causing a significant thickening of the ileum muscular layer. Senescent intestinal myocytes displayed many mitochondria with disorganized cristae and the presence of cytosolic lamellar corpuscles. Lipid peroxidation of ileum and gastrocnemius muscle, but not of the heart, increased in aged mice, thus suggesting enhanced oxidative stress. With exception of the intestinal muscle responsiveness, animals submitted to a daily session of 60 min, 5 days/wk, at 13 up to 21 m/min of moderate running in treadmill during animal life span exhibited a reversion of all the observed aging effects on intestinal, skeletal, and heart muscles. The introduction of this lifelong exercise protocol prevented the enhancement of lipid peroxidation and sarcopenia and also preserved cellular and ultracellular structures of the ileum. This is the first time that the protective effect of a lifelong regular aerobic physical activity against the deleterious effects of aging on intestinal muscle was demonstrated. moderate exercise; C57B/6 mice; ileum; oxidative stress; isometric contractile response Address for reprint requests and other correspondence: J. Aboulafia, Dept. of Biophysics, Universidade Federal de São Paulo-Escola Paulista de Medicina, Rua Botucatu, 862, 7° andar, 04023-062 São Paulo, SP, Brazil (e-mail: jan{at}biofis.epm.br )