The reactive carbonyl derivatives of proteins did not <a href="http://www.targetmol.com/compound/Asiatic-acid"></a>
increase with aging.However, when the muscle homogenate was exposed to a mixture of mM iron sulfate and mM ascorbic acid, the muscle of old control animals accumulated more RCD than that of the trained or adult groups.The chymotrypsinlike activity of proteasome complex increased in muscle of old trained rats.These changes must be the result of certain cellular alterations.However, the cellular and molecular mechanisms underlining these changes are poorly understood.It is well known that exercise increases the formation of reactive oxygen and nitrogen species. It is also clear that moderate regular exercise is likely to cause adaptations to antioxidant and oxidative damage repair systems. Therefore, it appears that oxidative stressinduced adaptations might play an important role in the beneficial effects of regular exercise.The incidence of diseases, such as certain types of cancers, rheumatic inflammation, diabetes II, and muscular dystrophy, is increased as a function of age. One of the most accepted theories of aging claims that aging is associated with increased formation of RONS, decreased capacity of antioxidant and repair systems, and increased accumulation of oxidative damage in macromolecules. Skeletal muscle is the tissue with the largest mass in the body, and consists of postmitotic cells, which are more prone to accumulate oxidative damage. Aging is associated with sarcopenia and dysfunction in motor coordination.The exerciseinduced adaptation is well described in skeletal muscle.Therefore, the current investigation was stimulated by the hypothesis that adaptation induced by regular exercise results in decreased accumulation of oxidative damage of DNA and proteins.We further suggest that exercise training attenuates the ageassociated decrease in protein and DNA repair.In addition, we propose that aged skeletal muscle will be more prone to exogenous oxidative stress than middleaged muscle and exercise training could increase the resistance against oxidative stress.The animals had a mean life span of months in our animal facility. At the end of this period, animals from each age group were weight matched and randomly assigned to either a sedentary control or an endurance exercise trained group.Hence, four experimental groups were formed: old exercise trained.The treadmilltraining program was intended to exercise both adult and old animals at the same relative exercise intensity for the two age groups during the week training period.Electric shock was rarely used to motivate the animals to run.Briefly, animals were placed in a sealed treadmill chamber that allowed a unidirectional flow of gas and the progressive exercise test began on a grade at the initial speed used for training. After a purge with a nitrogen stream, the mixtures were incubated at C for hto digest the DNA to nucleotides.units of alkaline phosphatase were added and the mixture was incubated at C for hto hydrolyze the nucleotides to nucleosides.The protein levels were measured by the BCA method.The reaction was carried out at C for min and stopped by placing the solution on ice.After min heating at C, samples were chilled and loaded into polyacrylamide gel with M urea and TBE and run at mV for h.Radioactive signal densities were determined using the software designed for this system.