Hepatic lipid peroxidation and antioxidant enzyme responses to long-term voluntary physical activity and aging

Abstract

Hepatic lipid perioxidation and antioxidant capacities as a function of aging and long-term voluntary physical activity were investigated in C57BI/6 mice. Female mice ages 1, 5 and 15 months were divided into control (C) or voluntary wheel trained (WT) groups (n=6 animals/grp). Voluntary wheel training consisted of unlimited access to a 16 cm wheel. Animals were sacrificed following training at 4, 8 and 24 months of age. The total distance run per day was 2.5 times greater in the 4 month old animals as compared the 8 or 24 month old animals (1.9 and 2,1 km/day, respectively). Malondialdehyde (MDA) levels were assessed as a marker of lipid perioxidation. MDA levels increased 2.5 fold from 4 to 24 months of age and were significantly lower in all age groups following chronic physical activity. Glutathione perioxidase (GSH-px), catalase (CAT), and mitochondrial (MnSOD), cytosolic (CuZnSOD) and total superoxide dismutase (SOD) levels were all significantly decreased with increasing age. Chronic physical activity significantly increased GSH-px and CAT levels at all ages and to a lesser extent CuZnSOD and total SOD in the 8 and 24 month old animals. MnSOD was unaffected by chronic physical activity at all ages. These findings suggest chronic physical activity provides a protective effect in this tissue against active O2 mediated cellular damage accompanying aging and this protective effect is partly related to elevations in GSH-px and CAT and to a lesser extent cytosolic SOD.