Age-specific decrease in aerobic efficiency associated with increase in oxygen free radical production in Drosophila melanogaster

This study was designed to test the free radical theory of aging by using D rosophila melanogaster as a model system. Oxygen free radicals are generate d by mitochondria during the process of normal oxidative metabolism. Age-sp ecific measurements of oxygen consumption, heat production and anti-oxidant enzyme activity were obtained from two inbred lines of male flies, one sel ected for longevity and one normal-lived. The findings of this study demons trate that although oxygen consumption remains relatively constant over the majority of the life span of each line of flies, aerobic efficiency declin es with advancing age. This loss of aerobic efficiency manifests itself as a decline in total body metabolism as measured by heat production, and appe ars to be associated with an age-specific increase in damage inflicted upon mitochondria by oxygen free radicals. (C) 2000 Elsevier Science Ltd. All r ights reserved.