"Oxidative stress" and muscle aging: influence of age, sex, fiber composition and function

Aim of this research was to study human muscle aging and the influence of oxidative stress correlated with physiological factors (age, sex, fiber composition and function) by measuring the antioxidant enzymes activities: total and mitochondrial superoxide dismutase (total and MnSOD), catalase (CAT), glutathione peroxidase (GSHPx) the levels of glutathione and glutathione disulfide (GSH and GSSG) and redox index. We also measured the lipid peroxide amount . As about age-related changes, we studied 120 samples (18-91 year-old) and we noted the presence of a correlation between age and ROS-mediated damages. Futhermore, it seems that 65 years could be the age at which ROS-dependent damage becomes crucial and begins to show up. Our data about sex-dependent changes showed how males may be potentially more vulnerable to oxidative damage than females. Study about fiber composition in old group (65-90 year-old) reported that subjects with +40% type II fibers not only have lipoperoxide levels lower but also detossifing system against superoxide anion more efficent than –40% type II fibers group. We also study aging process in muscle with different functions (“active”: characterized by rapid and coordinated changes during contraction, “inactive”: generating low levels of tension and maintaining this for a great duration). We observed that ROS-mediated oxidative mechanisms are different in “inactive” vs. “active” muscles