J Korean Geriatr Soc.
1998 Jun;2(1):1-7.
Mitochondria and Aging
- Affiliations
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- 1Department of Internal Medicine Geriatrics Clinic, Hangang Sacred Heart Hospital Hallym University College of Medicine, Seoul, Korea.
Abstract
- Mitochondrion has an important role in energy production in the cell. The importance has caused several workers to investigate its DNA and the expression of its genes during aging. Mitochondrial DNA (mtDNA) has no introns and replicates autonomously. A mitochondrion may have two or three copies of mtDNA and each cell may have many thousands of mitochondria. Any damage to mtDNA is expected to impair energy Production. Damage, modification, mutations, and deletions in mtDNA during the life span may affect energy production in human and contribute to aging. Free radicals are constantly being produced in mitochondria due to the high rate of oxidation in it. Free radicals may cause point mutation, increase deletions, and promote supercoiling, thereby affecting transcription. These changes in mtDNA are of general occurrence during aging. But there remains many unresolved questions. As an example, it is necessary to explain why the level of SOD, which is coded by a nuclear gene, decrease with age. Moreover, the nuclear gene is for in excess of the mtDNA and also codes for proteins that are for in excess in number and types. We are waiting for further results.
