Effect of age and metabolic rate on lipid peroxidation in the housefly, Musca domestica L.

The objective of this study was to explore the mechanism by which metabolic rate may affect life span by determining the relationship between lipid peroxidation potential and experimentally altered life spans in the adult housefly. Lipid peroxidation potential, measured in vitro, provides an indication of the relative conditions within the tissues affecting the susceptibility of polyunsaturated fatty acids to undergo non-enzymic peroxidation. Lipid peroxidation potential increased with age at a significantly faster rate in houseflies raised at 30 degrees C as compared to those kept at 25 degrees C. The life span of flies at 25 degrees C was longer and metabolic rate lower than at 30 degrees C. The effect of physical activity on lipid peroxidation potential was studied by comparing flies maintained under high and low physical activity regimes. Lipid peroxidation potential increased at a relatively greater rate with age in high-activity flies. The results suggest that accelerated senescence associated with higher metabolic rates, increases the rate of age-associated decline in the ability of houseflies to counteract lipid peroxidation in vitro.