Figure 6. Cytosolic and mitochondrial Ca2+ transients differ according to age (A) Cytosolic Ca2+ peak transients are diminished in skeletal muscle fibers from adult and old mice. (B) Resting mitochondrial Ca2+ levels differ in the different stages of lifespan in mice. Mitopericam data are expressed as the 490/420 nm ratio. Upon ATP stimulation, mitochondrial Ca2+ transients were observed. We show representative traces of each age group.