Age- and time-dependent mitochondrial genotoxic and myopathic effects of beta-guanidinopropionic acid, a creatine analog, on rodent skeletal muscles

B-guanidinopropionic acid (GPA) is a creatine analog hypothesized to have beneficial effects on hypertension, diabetes, and obesity, all of which manifest in aged individuals. Known side effects of GPA include mitochondrial and myopathic alterations, and specifically, the promotion of age-induced mtDNA deletion mutations. We hypothesized that mtDNA deletion mutations contribute to age-induced muscle degeneration and used the deletion mutation promoting effect of GPA to contrast the impact of mtDNA deletions on muscles that exhibit differential vulnerability to aging.