SciELO - Scientific Electronic Library Online

vol.92 issue5Relationship between electrocardiogram with diabetes mellitus and metabolic syndrome in Japanese-BraziliansDose-response curve to exercise in hypertensive individuals: analysis of the number of sessions to the hypotensive effect author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




Related links


Arquivos Brasileiros de Cardiologia

Print version ISSN 0066-782XOn-line version ISSN 1678-4170


MAIFRINO, Laura Beatriz Mesiano et al. Effect of exercise training on aging-induced changes in rat papillary muscle. Arq. Bras. Cardiol. [online]. 2009, vol.92, n.5, pp.387-392. ISSN 0066-782X.

BACKGROUND: The effects of aging on papillary muscle have been widely demonstrated, but no data on the effects of exercise on the age-related changes are available. OBJECTIVE: To analyze the effects of aging on the morphological and quantitative properties of papillary muscle and investigate whether a long-term moderate exercise program would exert a protective effect against the effects of aging. METHODS: We used electron microscopy to study the density of myocytes, capillaries and connective tissue and the cross-sectional area of myocytes of the papillary muscle of the left ventricle of 6- and 13-month-old untrained and exercised Wistar rats. RESULTS: As expected, the volume density of myocytes declined significantly (p<0.05) with aging. The length density of myocardial capillaries also declined with aging, but not significantly. The interstitial volume fraction of the papillary muscle tissue increased significantly (P<0.05) with age. The number of myocyte profiles showed a reduction of 20% that was accompanied by myocyte hypertrophy in the aged rats (P<0.05). Animals submitted to a 60-minute daily session,, 5 days/wk at 1.8 km.h-1 of moderate running on a treadmill for 28 weeks showed a reversion of all the observed aging effects on papillary muscle. CONCLUSION: The present study supports the concept that long-term exercise training restrains the aging-related deleterious changes in the papillary muscle.

Keywords : Exercise; papillary muscles; aging; rats.

        · abstract in Portuguese | Spanish     · text in English | Portuguese | Spanish     · English ( pdf epdf ) | Spanish ( pdf epdf ) | Portuguese ( pdf epdf )


Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License