Fig. 5.

Protein and DNA synthesis in cultured myoblasts during an H₂O₂ challenge. A: control (CON) + H₂O₂ decreased DNA fractional synthesis rate (FSR) compared with CON, with H₂O₂ + Protandim (Pro) lower than CON + H₂O₂. B: mitochondrial FSR was not different between treatments. C: compared with CON + H₂O₂, H₂O₂ + Pro increased the ratio of mitochondrial (Mito) protein to DNA synthesis, indicating improved proteostatic maintenance. D: vitamin C (VitC) and Pro in combination with H₂O₂ decreased cytosolic FSR compared with CON + H₂O₂. E: CON + H₂O₂ increased the ratio of cytosolic (Cyto) protein to DNA synthesis while H₂O₂ + Pro was greater than CON + H₂O₂. Myoblasts were treated with 50 µM H₂O₂ alone (+) or in combination with ethanol (EtOH), 50 µM VitC, 100 mg/ml Pro, or left untreated (−) for 12 h in 4% deuterium oxide (D₂O)-enriched media. Data were assessed by 1-way ANOVA with planned contrasts and presented as means ± SE. *P < 0.05; n = 3/group, except CON + H₂O₂ Mito FSR and Mito protein-to-DNA ratio; n = 2/condition.