Title

Recovery Time Course in Contractile Function of Fast and Slow Skeletal Muscle after Hindlimb Immobilization

Document Type

Article

Language

eng

Format of Original

6 p.

Publication Date

3-1982

Publisher

American Physiological Society

Source Publication

Journal of Applied Physiology

Source ISSN

0021-8987

Abstract

Contractile properties were evaluated in rats remobilized after 6 wk of hindlimb casting to evaluate the regenerative capacity of fast and slow skeletal muscles. Contractile parameters were determined in vitro (22 degrees C) in the type I soleus (SOL), type IIA and IIB extensor digitorum longus (EDL), and the type IIB superficial vastus lateralis (SVL). Immobilization (IM) shortened the SOL isometric twitch duration after which contraction time and half-relaxation time required 4 and 7 days to recover, respectively. In contrast, IM prolonged the twitch in the EDL and SVL and recovery required 14 and 7 days, respectively. Peak tetanic tension (g/cm2) fell in the SOL and EDL with IM and full recovery required 28 days. In this regard, the SVL remained unaltered. Rates of tension development and decline remained essentially unaltered in the fast muscles after IM but fell in the SOL, requiring 14 days to fully recover. Maximal shortening velocity, which had been elevated in all three muscles by IM, recovered rapidly. The present results demonstrate that both fast and slow muscle have the ability to completely recover from 6 weeks of IM.

Comments

Journal of Applied Physiology, Vol. 52, No. 3 (March 1982): 677-682. Permalink.