Age and sex influence on oxidative damage and functional status in human skeletal muscle

A reduction in muscle mass, with consequent decrease in strength and resist ance, is commonly observed with advancing age. In this study we measured ma rkers of oxidative damage to DNA, lipids and proteins, some antioxidant enz yme activities as well Ca2+ transport in sarcoplasmic reticulum membranes i n muscle biopsies from vastus lateralis of young and elderly healthy subjec ts of both sexes in order to evaluate the presence of age- and sex- related differences. We found a significant increase in oxidation of DNA and lipid s in the elderly group, more evident in males, and a reduction in catalase and glutathione transferase activities. The experiments on Ca2+ transport s howed an abnormal functional response of aged muscle after exposure to caff eine, which increases the opening of Ca2+ channels, as well a reduced activ ity of the Ca2+ pump in elderly males. From these results we conclude that oxidative stress play an important role in muscle aging and that oxidative damage is much more evident in elderly males, suggesting a gender differenc e maybe related to hormonal factors.