THE INFLUENCE OF RAT SUSPENSION-HYPOKINESIA ON THE GASTROCNEMIUS-MUSCLE

  • 1 January 1984
    • journal article
    • research article
    • Vol. 55  (5) , 381-386
Abstract
Hind-limb hypokinesia [a simulation of weightlessness] was induced in rats by the Morey method to characterize the response of the gastrocnemius muscle. A comparison of rats suspended for 2 wk with weight, sex and litter-matched control rats indicated no difference in gastrocnemius wet weight, contraction, or 1/2 relaxation times, but less contractile function. Myosin ATPase staining identified uniform type I (slow-twitch) and II (fast-twitch) atrophy in the muscles from 4 of 10 rats suspended for 2 wk and 1 of 12 rats suspended for 4 wk; muscles from 3 other rats of the 4-wk group displayed greater type I atrophy. Other histochemical changes were characteristic of a neuropathy. These data together with recently acquired soleus data (29) indicate the Morey model, like space flight, evokes greater changes in the type I or slow twitch fibers of the gastrocnemius and soleus muscles.

This publication has 3 references indexed in Scilit: