Redox control of signalling responses to contractile activity and aging in skeletal muscle

During aging loss of skeletal muscle mass and function has a si gnificant effect of an individual’s quality of life and ability to maintain independence. Both loss of muscle fibres and atrophy of the remaining fibres play a role in the mus cle decline and this is associated with loss of motor units and a reduction in the number of motor neurons. Increased oxidative damage has long been claimed to be associated with aging and many studies have reported increased amounts of oxidative damage markers are found in tissues from old organisms. Reactive oxygen species (ROS) are recognised to play a major role in cell signalling and in muscle ROS generated during contractile play an important role in signalling adaptations to contractile activity. These ’redox-regulated’ pathways are beneficial adaptations which are attenuated during aging. This review will briefly cover what is currently known about the mechanisms underlying these muscle adaptations to exercise, how they are affected by aging and assess the importan ce of these pathways in age-related loss of skeletal muscle mass and function.