Lipid peroxidation in the skeletal muscle of hamsters with emphysema

Current evidence suggests that skeletal muscle functional impairments present in emphysema and COPD patients may in part be a consequence of the disease condition per se. The mechanistic basis for these impairments is uncertain. Within the human population, it is difficult to control for confounding effects of concomitantly reduced activity levels. To explore this issue, malondialdehyde (MDA), a marker of lipid peroxidation, and enzymes of the glutathione redox system were measured in selected hindlimb muscles of Syrian Golden hamsters 6 months following intratracheal instillation of either saline (CON, n=7) or elastase (25 U/100 g body weight, EMP, n=5) in an accepted model where physical activity levels between control and EMP groups could be equated. Excised lung volume increased with EMP (CON, 1.3+/-0.2 g; EMP, 3.2+/-0.4 g, P<0.01). MDA was increased in the gastrocnemius (CON, 238+/-87; EMP, 371+/-122 nmol/g protein, P<0.05) of EMP hamsters. Antioxidant concentrations had a disparate response; glutathione (CON, 7.68+/-1.53; and EMP, 10.25+/-0.67 &mgr;mol/g protein, P<0.01) and the activity of glutathione reductase (GR) were increased (CON, 1.87+/-0.17; and EMP, 2.46+/-0.31 U/g protein, P<0.01) in the gastrocnemius, whereas the activity of glutathione peroxidase (GPx) was decreased (CON, 12.7+/-2.65; and EMP, 9.46+/-1.88 U/g protein, P<0.05) in the vastus lateralis of EMP hamsters. CONCLUSION: These data indicate that EMP may induce oxidative stress in peripheral skeletal muscle.