tayel, S., Abdel-Hady El-Safty, F., El-Sherif, N., faried, M. (2021). Histological Structure of Skeletal Muscle in Disuse Muscle Atrophy and Role of Exercise. Egyptian Journal of Histology, 44(1), 1-7. doi: 10.21608/ejh.2020.24537.1252
sara gamal tayel; Fatma El-Nabawia Abdel-Hady El-Safty; neveen El-Sherif; manar faried. "Histological Structure of Skeletal Muscle in Disuse Muscle Atrophy and Role of Exercise". Egyptian Journal of Histology, 44, 1, 2021, 1-7. doi: 10.21608/ejh.2020.24537.1252
tayel, S., Abdel-Hady El-Safty, F., El-Sherif, N., faried, M. (2021). 'Histological Structure of Skeletal Muscle in Disuse Muscle Atrophy and Role of Exercise', Egyptian Journal of Histology, 44(1), pp. 1-7. doi: 10.21608/ejh.2020.24537.1252
tayel, S., Abdel-Hady El-Safty, F., El-Sherif, N., faried, M. Histological Structure of Skeletal Muscle in Disuse Muscle Atrophy and Role of Exercise. Egyptian Journal of Histology, 2021; 44(1): 1-7. doi: 10.21608/ejh.2020.24537.1252
Histological Structure of Skeletal Muscle in Disuse Muscle Atrophy and Role of Exercise
1Anatomy and Embryology, Faculty of Medicine, Menoufia University, Menoufia, Egypt
2anatomy and embryology department faculty of medicine, menoufia university, Menoufia, Egypt.
Abstract
Disuse muscle atrophy is one of the most important research topics in fields of rehabilitation and clinical medicine. It refers to morphological and functional alteration of skeletal muscle under the states of hypokinesia, immobilization and weightlessness. This review analyzes a number of structural and functional changes in the skeletal muscle tissue in case of muscle disuse which appeared in loss in the muscle mass, reduction in the transverse diameter of most of muscle fibers, wide spaces between muscle fibers, increase collagen fiber deposition and appearance of apoptotic nuclei in muscle fibers besides sensorial dysfunction such as hypo mechanical responsiveness and diminished contractile function. In addition to the ultrastructural alteration, which include loss of sarcomere organization, indistinguishable A and I bands, irregular distorted Z-line with disruption of myofilaments and fused giant accumulated mitochondria. The review summarizes also the molecular mechanisms of skeletal muscle disuse atrophy which could be resulted from an alteration in the activity of oxidative stress enzymes and lead to increase in protein degradation and/or a reduction in protein synthesis. Moreover, the review discusses the efficiency of potential countermeasures of stretching exercise as a very powerful stimulant of muscle growth and muscle protein synthesis to counteract the structural and functional alterations in muscle tissue caused by disuse. The review showed that stretching exercise can increase the transverse sectional area of muscle fibers, produce a rise in the number of sarcomeres in series and prevent muscle atrophy. Passive stretching also completely prevented the decrease in myonuclear number induced by inactivity. Moreover, stretching accelerated the amelioration of the range of motion limitation and prevent the deposition of connective tissue resulted from disuse muscle atrophy.