Training effects on soleus of cats spinal cord transected (T12-13) as adults.
Adult spinal cord transected (T12-13) cats were trained for 30 min/day, 5 days/week to either step on a treadmill (Stp-T) or stand (Std-T) for approximately 5 months. Training ameliorated soleus atrophy and enhanced maximum force capability compared to nontrained (N-T) spinal cats, with Stp-T being significantly different from N-T. Isometric twitch speed and maximum rate of shortening were unaffected by training; the soleus of all spinal groups was significantly faster than control. There was an elevation in myosin adenosine triphosphatase activity and a shift toward faster myosin heavy chain and fiber type compositions in N-T and Std-T, but not Stp-T cats. Thus, rhythmical activity involving muscle length and force changes (stepping) was more effective than a similar amount of a more static activity (standing). This specificity related to the type of training should be considered when developing rehabilitative strategies following spinal cord injury.
Roy
R R
RR
Brain Research Institute, UCLA School of Medicine, Center for the Health Sciences, Los Angeles, California 90095-1761, USA.
Talmadge
R J
RJ
Hodgson
J A
JA
Zhong
H
H
Baldwin
K M
KM
Edgerton
V R
VR
D000818:Animals; D001835:Body Weight; D002415:Cats; D002950:Citrate (si)-Synthase / Q000378:metabolism; D007537:Isometric Contraction; D009046:Motor Neurons / Q000502:physiology; D018482:Muscle, Skeletal / Q000166:cytology / Q000294:innervation / Q000502:physiology*; D009210:Myofibrils / Q000502:physiology; D018995:Myosin Heavy Chains / Q000096:biosynthesis; D009218:Myosins / Q000096:biosynthesis; D009929:Organ Size; D010805:Physical Conditioning, Animal; D013116:Spinal Cord / Q000502:physiology*
D002950:Citrate (si)-Synthase; D018995:Myosin Heavy Chains; D009218:Myosins