Journal of Applied Physiology, Vol 69, Issue 3 861-867, Copyright © 1990 by American Physiological Society

ARTICLES

Mechanical deficit persists during long-term muscle hypertrophy

S. C. Kandarian and T. P. White
Department of Kinesiology, University of Michigan, Ann Arbor 48109-2214.

Hypotheses were tested that the deficit in maximum isometric force normalized to muscle cross-sectional area (i.e., specific Po, N/cm2) of hypertrophied muscle would return to control value with time and that the rate and magnitude of adaptation of specific force would not differ between soleus and plantaris muscles. Ablation operations of the gastrocnemius and plantaris muscles or the gastrocnemius and soleus muscles were done to induce hypertrophy of synergistic muscle left intact in female Wistar rats (n = 47) at 5 wk of age. The hypertrophied soleus and plantaris muscles and control muscles from other age-matched rats (n = 22) were studied from days 30 to 240 thereafter. Po was measured in vitro at 25 degrees C in oxygenated Krebs-Ringer bicarbonate. Compared with control values, soleus muscle cross-sectional area increased 41-15% from days 30 to 240 after ablation, whereas Po increased 11 and 15% only at days 60 and 90. Compared with control values, plantaris muscle cross-sectional area increased 52% at day 30, 40% from days 60 through 120, and 15% at day 240. Plantaris muscle Po increased 25% from days 30 to 120 but at day 240 was not different from control value. Changes in muscle architecture were negligible after ablation in both muscles. Specific Po was depressed from 11 to 28% for both muscles at all times. At no time after the ablation of synergistic muscle did the increased muscle cross-sectional area contribute fully to isometric force production.

This article has been cited by other articles:

				C. L. Mendias, J. E. Marcin, D. R. Calerdon, and J. A. Faulkner Contractile properties of EDL and soleus muscles of myostatin-deficient mice J Appl Physiol, September 1, 2006; 101(3): 898 - 905. [Abstract] [Full Text] [PDF]

				J. L. Staib, S. J. Swoap, and S. K. Powers Diaphragm contractile dysfunction in MyoD gene-inactivated mice Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2002; 283(3): R583 - R590. [Abstract] [Full Text] [PDF]

				C. E. Kasper and L. P. Sarna Influence of Adjuvant Chemotherapy on Skeletal Muscle and Fatigue in Women with Breast Cancer Biol Res Nurs, October 1, 2000; 2(2): 133 - 139. [Abstract] [PDF]

				W. R. Frontera, D. Suh, L. S. Krivickas, V. A. Hughes, R. Goldstein, and R. Roubenoff Skeletal muscle fiber quality in older men and women Am J Physiol Cell Physiol, September 1, 2000; 279(3): C611 - C618. [Abstract] [Full Text] [PDF]

				E. R. Blough and J. K. Linderman Lack of skeletal muscle hypertrophy in very aged male Fischer 344 x Brown Norway rats J Appl Physiol, April 1, 2000; 88(4): 1265 - 1270. [Abstract] [Full Text] [PDF]

				R. R. Roy, R. J. Talmadge, K. Fox, M. Lee, A. Ishihara, and V. R. Edgerton Modulation of MHC isoforms in functionally overloaded and exercised rat plantaris fibers J Appl Physiol, July 1, 1997; 83(1): 280 - 290. [Abstract] [Full Text] [PDF]