Reactive Oxygen Species (ROS) have a role in cell signalling in skeletal muscle. During ageing ROS accumulate with an altered redox modulation of muscle physiology.

We investigated the age-dependence of ROS action on i) the myogenic potential and ii) the neuromuscular transmission.

To investigate the role of ROS during myogenesis, murine satellite cells were used. 5 min application of 100 mM H2O2 induced Ca2+ transients in young and old cells, highlighting its role as second messenger. We evaluated the proliferative capacity and the efficiency of differentiation after 30 min treatment with 3 and 100 mM H2O2. H2O2 3 mM increased the proliferative capacity of young cells and reduced the proliferation of old cells. H2O2 100 mM decreased the ability to proliferate of young and more dramatically old cultures. 3 and 100 mM H2O2 did not affect the myoblast fusion.

ROS action on neuromuscular transmission was assessed on rat diaphragm muscle. We found a presynaptic action of ROS on transmitter release. H2O2 300 mM suppressed quantal transmitter release of adult rats. This action was more robust in old animals and absent in neonatal rats. Our data indicated an age-dependent inhibitory action of oxidative stress on skeletal muscle cells and neuromuscular transmission. They support the idea of an altered redox modulation in aged muscle cells and motoneurons.