Why the study?
Does aging alter the elastic and contractile characteristics of single skeletal muscle fibers in men?
Does aging alter the elastic and contractile characteristics of single skeletal muscle fibers in men?
Aging increases stiffness and reduces specific force and shortening velocity in type I and IIa skeletal muscle fibers, though these changes may not directly influence each other.
May contribute to sarcopenia-related weakness; leaves open effects on whole-muscle function or interventions.
The current investigation was designed to: (a) assess the impact of aging on elastic characteristics of single skeletal muscle fibers from young (N = 6) and older men (N = 6); and (b) correlate the potential changes, with the fiber contractile properties. Chemically skinned single muscle fibers (n = 235) from vastus lateralis muscle were maximally activated. Maximal force and cross-sectional area were measured, and specific force calculated. The slack test was used to measure maximal unloaded shortening velocity. A quick release of 0.15% of fiber length was applied to determine instantaneous stiffness. The myosin heavy chain isoform composition of each single fiber was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Aging induces changes in both fiber elasticity (i.e., increased instantaneous stiffness) and contractility (i.e., reduced specific force and unloaded shortening velocity) in type I and IIa fibers. However, the changes in fiber stiffness may not directly influence contractile characteristics alterations.
No takes yet. Share an insight, caveat, or question.
Ochala et al. (2007) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: