Influence of age, sex, and sexual activity on trace element levels and antioxidant enzyme activities in field mice (Apodemus sylvaticus and Mus spretus)

The influence of age, gender and sexual activity on both hepatic levels of some trace elements (Fe, Cu, Zn, Mn, Se) and the activities of glutathione-S-transferase (GST) and superoxide dismutase (SOD) was investigated in Wood mice (Apodemus sylvaticus) and Algerian mice (Mus spretus). Animals were taken from a riverside community of an unpolluted area of central Portugal. Adult A. sylvaticus presented the highest hepatic mean concentrations of Cu and Mn, whereas adult M. spretus had the highest Fe concentration in the liver. Moreover, an influence of age on the contents of Fe, Zn, and Mn has been observed in A. sylvaticus, whereas in M. spretus an influence of gender and sexual activity was only detected on Zn levels. In contrast, enzyme activities were not influenced by the studied variables, despite a tendency for an increase in SOD activity in sexually active M. spretus. GST activity was species dependent, whereas SOD activity was similar between species. These findings were analyzed regarding the relationship of both essential trace elements and the two antioxidant enzymes with physiological and metabolic pathways related to life cycles in the two species of mice. Results enhanced the understanding of A. sylvaticus and M. spretus as biological models, allowing their future use as bioindicators of environmental toxicity.