Abstract
The activities of mitochondrial respiratory chain enzymes with and without ascorbate pretreatment were assayed in 10- to 20-week-old cultures of human fibroblasts. Aging was associated with a significant loss of respiratory chain enzyme activities. The presence of ascorbate in the medium reduced the rate of loss of these enzymes. Free radical-mediated injuries may also contribute to aging since the changes seen in respiratory chain enzyme activities are similar to those seen in oxidatively stressed cells. This study demonstrates an age-related decline in mitochondrial respiratory chain activity as well as a protective role for ascorbate in aging.
MeSH terms
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Ascorbic Acid / pharmacology*
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Cells, Cultured
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Cellular Senescence / physiology
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Citrate (si)-Synthase / metabolism
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Electron Transport / drug effects
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Electron Transport / physiology*
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Electron Transport Complex II
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Electron Transport Complex III / metabolism
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Electron Transport Complex IV / metabolism
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Fibroblasts / cytology
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Fibroblasts / enzymology
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Free Radicals / metabolism
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Humans
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Male
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Mitochondria / drug effects
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Mitochondria / enzymology*
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Multienzyme Complexes / metabolism
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NAD(P)H Dehydrogenase (Quinone) / metabolism
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Oxidative Stress / physiology
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Oxidoreductases / metabolism
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Succinate Dehydrogenase / metabolism
Substances
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Free Radicals
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Multienzyme Complexes
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Oxidoreductases
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Electron Transport Complex II
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Succinate Dehydrogenase
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NAD(P)H Dehydrogenase (Quinone)
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Electron Transport Complex IV
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Citrate (si)-Synthase
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Electron Transport Complex III
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Ascorbic Acid