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Updated: Feb 3, 2026

Procedures for Rat in situ Skeletal Muscle Contractile Properties
Published on: October 15, 2011
Apoptotic changes in a full-lengthened immobilization model of rat soleus muscle
Hye Rim Suh1, Eui Ho Park1, Sun Wook Moon1
1Department of Physiology, College of Medicine and Neuroscience Research Institute, Korea University, Seoul, 136-705, South Korea.
Introduction:
Lengthened immobilization may prevent muscle shortening, and help maintain normal muscle length. However, its apoptotic effects remain unclear. We evaluated the effects of long-term immobilization on apoptotic proteins.
Methods:
Rat soleus muscles were immobilized by casting in a neutral (NEUT) or lengthened (LENG) position for 21 days. We evaluated dynamic weight load and muscle atrophy following the 21-day period using hematoxylin and eosin staining. We measured Bax (pro-apoptotic Bcl-2 family member), MyoD (myogenic differentiation factor D), MYH (myosin heavy chain), and cleaved poly(ADP-ribose)polymerase levels and examined apoptotic nucleus expression.
Results:
Decreased dynamic weight load and muscle atrophy changes were observed in LENG. Both NEUT and LENG showed significantly reduced levels of MYH. LENG showed a significant increase in Bax and MyoD expression as well as in the number of apoptotic nuclei.
Conclusions:
Long-term lengthened immobilization may increase apoptotic changes and decrease muscle formation proteins in muscle. Muscle Nerve 59:263-269, 2019.
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