Aging and the Acute Phase Response to Exercise: Implications for the Role of Systemic Factors on Skeletal Muscle Protein Turnover

Declines in exercise capacity throughout an individual's life span can affect function and can ultimately limit the ability to perform activities of daily living. Along with these changes in exercise capacity and function, studies have reported age-associated changes in several parameters of immune status including declines in cell-mediated and humoral immunity. Exercise has been shown repeatedly to activate host-specific defense mechanisms in a series of coordinated metabolic events similar to the acute phase response to infection. This review will focus on the role of the acute phase response on skeletal muscle remodeling after exercise. In particular, we will discuss the physiological role of exercise-induced neutrophilia and monocyte production of the cytokine interleukin-1 on skeletal muscle remodeling in young and older individuals. The implications of these responses in mediating the metabolic adaptations to exercise will be addressed.

Key words

Interleukin-1 - neutrophil - proteolysis - creatine kinase - acute phase response