Age- and Muscle-Specific Oxidative Stress Management Strategies in a Long-Lived Diver, the Weddell Seal

The free radical theory of aging purports that the accumulation of cellular oxidative damage leads to aging. While this process is not expected to manifest in wild populations, which can suffer from early predation or injury-induced mortality, physically active long-lived mammals are a model in which cellular aging may occur. Air breathing divers such as seals experience repeated bouts of ischemia-reperfusion, potentially exposing their tissues to oxidative stress and thus damage and accelerated aging. We have previously demonstrated that skeletal muscle cellular morphology “ages” in Weddell seals without a corresponding decrease in diving behavior. This suggests stress response may protect against oxidative damage and functional impairment, providing insight into mechanisms for managing oxidative stress. We studied whether muscular senescence might arise from oxidative damage by comparing muscle from old (age 17–27 years) and young (age 9–16 years) cohorts of adult Weddell seals. Muscle biopsies were col...