Muscle aging is associated with compromised Ca2+ spark signaling and segregated intracellular Ca2+ release.

ABSTRACT: Reduced homeostatic capacity for intracellular Ca2+ ([Ca2+]i) movement may underlie the progression of sarcopenia and contractile dysfunction during muscle aging. We report two alterations to Ca2+ homeostasis in skeletal muscle that are associated with aging. Ca2+ sparks, which are the elemental units of Ca2+ release from sarcoplasmic reticulum, are silent under resting conditions in young muscle, yet activate in a dynamic manner upon deformation of membrane structures. The dynamic nature of Ca2+ sparks appears to be lost in aged skeletal muscle. Using repetitive voltage stimulation on isolated muscle preparations, we identify a segregated [Ca2+]i reserve that uncouples from the normal excitation-contraction process in aged skeletal muscle. Similar phenotypes are observed in adolescent mus

SUBMITTER: Weisleder N 

PROVIDER: S-EPMC2064307 | biostudies-literature | 2006 Aug

REPOSITORIES: biostudies-literature