Functional overloading facilitates the regeneration of injured soleus muscles in mice.
The effect of functional overloading on the regenerating process of injured skeletal muscle was investigated in 10-week-old male mice (C57BL/6J). Functional overloading on soleus of both hindlimbs was performed by cutting the distal tendons of plantaris and gastrocnemius muscles for 2 weeks before cardiotoxin (CTX) injection as the preconditioning and also during 10 weeks of recovery. To activate the necrosis-regeneration cycle, 0.1 ml of 10-microM CTX was injected into soleus muscle. The mean values of absolute muscle weight and the percentage of Pax7-positive nuclei in soleus were increased by the preconditioning. These values, as well as total muscle protein content, in the group with CTX injection plus overloading were larger than in the group with CTX injection alone. Fibers with central nucleus were noted in the group with CTX injection with or without overloading. The rate of disappearance of fibers having central nucleus during recovery was stimulated by overloading. Histological analyses revealed that the regeneration of injured soleus muscle with overloading proceeded more rapidly than the muscle without overloading. These results, in combination with previous lines of evidence, strongly suggest that functional overloading may facilitate the regeneration of injured skeletal muscles.
Morioka
Shigeta
S
Department of Physiology, St. Marianna University School of Medicine, Kawasaki, 216-8511 Japan.
Goto
Katsumasa
K
Kojima
Atsushi
A
Naito
Toshihito
T
Matsuba
Yusuke
Y
Akema
Tatsuo
T
Fujiya
Hiroto
H
Sugiura
Takao
T
Ohira
Yoshinobu
Y
Beppu
Moroe
M
Aoki
Haruhito
H
Yoshioka
Toshitada
T
D000818:Animals; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism / Q000473:pathology; D049109:Cell Proliferation; D004195:Disease Models, Animal; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009119:Muscle Contraction; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000473:pathology; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D009135:Muscular Diseases / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology*; D009336:Necrosis; D009929:Organ Size; D051763:PAX7 Transcription Factor / Q000378:metabolism; D012038:Regeneration; D013314:Stress, Mechanical; D013710:Tendons / Q000601:surgery; D013997:Time Factors; D014118:Toxins, Biological
D009124:Muscle Proteins; D051763:PAX7 Transcription Factor; C497322:Pax7 protein, mouse; D014118:Toxins, Biological