Research Paper Volume 1, Issue 9 pp 818—830

Figure 5. Chronic stimulation-induced adaptations in mitochondrial function and anti-apoptotic cell death signaling in young and old animals. (A). and (B) State 4 (2 μM rotenone and 10 mM succinate as substrates) and state 3 (rotenone and succinate plus 0.44 mM ADP) rates of oxygen consumption (VO₂) in isolated subsarcolemmal (SS; A) and intermyofibrillar (IMF; B) mitochondria from the control (CON, open bars) and chronically stimulated (STIM, closed bars) limbs of young and old animals (n = 6-10). (C) and (D) State 4 and state 3 rates of reactive oxygen species (ROS) production per natom oxygen consumed in SS (C) and IMF (D) mitochondria from the CON and STIM limbs of young and old animals (n = 7-10). (E) Level of fragmented DNA, in the form of mono- and oligonucleosomes, in myonuclei-containing cytosolic extracts isolated from young and old animals (n: STIM = 4, CON = 21). Data represent the mean ± SEM. * P < 0.05 vs. Young; ¶ P < 0.05 vs. CON).