Apoptosis in young and old denervated rat skeletal muscle.
We investigated the apoptotic response to different degrees of denervation in young and older rats randomized into control (C), partial (PD), and complete denervation (CD) of muscles innervated by the sciatic nerve.



Muscle wet weight to body weight (MWW/BW), myosin heavy chain (MHC) isoforms, and fiber cross-sectional area were determined in gastrocnemius and soleus muscles. Apoptotic responses were determined by changes in myonuclei and expression of Bcl-2 and BAX.



PD and CD resulted in significant reductions in MWW/BW and FCSA in both young and older rats. Older controls had greater apoptotic responses than young controls. Apoptotic responses were greater in PD and CD than in C in both age groups. No statistical interaction between denervation and age group was seen.



Older age was associated with increased level of apoptosis, but older muscle was not more vulnerable to the effect of denervation. Muscle Nerve 55: 262-269, 2017.
Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 82, Gumi-ro 173, Bundang-gu, Seongnam-si, Gyeonggi-do, 13620, Republic of Korea.
Gangpyo
G
Lee
Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 82, Gumi-ro 173, Bundang-gu, Seongnam-si, Gyeonggi-do, 13620, Republic of Korea.
Jae-Young
JY
Lim
Department of Physical Medicine and Rehabilitation, Vanderbilt University Medical Center, Nashville, Tennessee, USA.|Department of Physiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico.
Walter R
WR
Frontera
D000375:Aging; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D004195:Disease Models, Animal; D020287:In Situ Nick-End Labeling; D008297:Male; D009121:Muscle Denervation; D018482:Muscle, Skeletal / Q000473:pathology*; D018995:Myosin Heavy Chains / Q000378:metabolism; D009929:Organ Size; D059348:Peripheral Nerve Injuries / Q000473:pathology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D051028:bcl-2-Associated X Protein / Q000378:metabolism
D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D018995:Myosin Heavy Chains
aging; apoptosis; denervation; muscle atrophy; rat; skeletal muscle