Skip Navigation LinksHome > July 2002 - Volume 34 - Issue 7 > Aging does not attenuate plantaris muscle hypertrophy in mal...
Medicine & Science in Sports & Exercise:
BASIC SCIENCES: Original Investigations

Aging does not attenuate plantaris muscle hypertrophy in male Fischer 344 rats


Collapse Box


LINDERMAN, J. K., and E. R. BLOUGH. Aging does not attenuate plantaris muscle hypertrophy in male Fischer 344 rats. Med. Sci. Sports Exerc., Vol. 34, No. 7, pp. 1115–1119, 2002.

Purpose: The present study examined the effect of extreme old age on the plasticity of the rat plantaris muscle in response to an increase in mechanical load.

Methods: Male Fischer 344 rats, aged 7 months (adult) and 25 months (old) underwent bilateral surgical ablation of the gastrocnemius muscle to functionally overload (OV) the fast-twitch plantaris muscle for 8 wk

Results: At 27 months of age, plantaris wet weight and cross-sectional area (CSA) were unaffected by age, but aging decreased peak isometric tension (Po) 27% (P < 0.05). Plantaris muscle myosin heavy chain composition indicated a loss of faster myosin heavy chains (MHC) isoforms with concomitant increases in slower MHC in old rats (P < 0.05). In adult rats, OV increased muscle CSA and Po 72% and 83%, respectively (P < 0.05). Similarly, OV increased CSA and Po 69% and 73%, respectively, in old rats (P < 0.05). Average fiber CSA increased 57% and 68% in adult-OV and old-OV rats, respectively (P < 0.05).

Conclusion: Collectively, our data indicate that plantaris muscle mass and plasticity in response to increased mechanical load are well conserved in very aged male Fischer 344 rats.

©2002The American College of Sports Medicine


Article Tools


Article Level Metrics

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.

Connect With Us