The dynamics of redox related elements (Fe, Co, Zn, and Se) were studied using instrumental neutron activation analysis as
a function of rat age in the range of 4 to 16 weeks. Activity levels of glutathione peroxidase (GSH-Px), thiobarbituric acid
reactive substance (TBARS) were assayed, and hydrogen peroxide (H2O2) concentrations were measured for the same liver homogenates using an X-band ESR spectrometer. The oxidative stress, the
aging effect, and the mineral valance are discussed.