RESUMO
This paper offers a literature review on the effects of immobilization on rat skeletal muscle tissue. The authors were unanimous with regard to the reduction in muscle mass, cross-section area and myonuclei in the muscles studied, especially in relation to the alteration in the regulation of the protein synthesis and degradation process as well as an alteration in the activity of oxidative enzymes caused by immobilization. With regard to the muscle fiber type, most authors report having found a greater amount of type 2 fibers over type 1 fibers, thereby implying an alteration in the contractile function of the affected muscle. These findings suggest greater degradation and/or substitution of tonic (postural or type 1) fibers by phasic (rapid contraction or type 2) fibers. Thus, the present study suggests that, regardless of the method employed, immobilization has harmful effects on skeletal muscle tissue in rats.