Premium
Myofibrillar disruption in the rabbit soleus muscle after one‐week hindlimb suspension
Author(s) -
Anzil Archinto P.,
Sancesario Giuseppe,
Massa Roberto,
Bernardi Giorgio
Publication year - 1991
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880140411
Subject(s) - myofibril , hindlimb , soleus muscle , sarcomere , anatomy , atrophy , suspension (topology) , chemistry , muscle atrophy , biology , medicine , endocrinology , skeletal muscle , myocyte , biochemistry , mathematics , homotopy , pure mathematics
Relevant muscle‐ and species‐specific differences may be found in the reaction of muscles to hindlimb suspension. This problem has been studied in 5 rabbits following a one‐week hindlimb suspension, and in 5 ground‐based controls. The soleus and the tibialis were prepared for light and transmission electron microscopy. In suspension the animals occasionally extended and flexed the hindlimbs, but, when standing still, their hindfeet were plantar‐flexed to an angle of 180°. In this position the length of the soleus was determined to be 35% less than in controls, whereas that of the tibialis was 30% more. Histologically, the tibialis fibers usually exhibited a preserved sarcomeric pattern, whereas soleus fibers displayed a regular sequence of areas of shortened sarcomeres, alternating with areas of myofibrillar disruption. These findings demonstrated that hindlimb suspension induces a focal breakdown of the soleus myofibrils, probably dependent on the reduced longitudinal tension of the suspended soleus and its phasic contractions against no load. It is conceivable that similar factors could also be responsible for soieus muscle atrophy induced by hypogravity as well as by other clinical conditions during which a stressful plantar flexion of the feet occurs against no load.