The desire to age well is a common goal among the human population. How to do so is therefore, a popular question. One theory of ageing involves the accumulation of damage to mitochondrial protein and the subsequent loss of function the damage causes. Increasing the rate of mitochondrial protein synthesis, a variable that declines with advancing age, is one way to improve quality of life in the twilight years. A review of literature lead to a multi-level approach, with measurements of protein synthesis made at the whole body, muscle, and molecular levels. An acute bout of aerobic exercise, followed by feeding, two factors which have a positive effect on the rate of mitochondrial protein synthesis, was used. Adaptations to a period of exercise training are mediated by the accumulation of proteins due to each acute exercise bout, and so an acute intervention was postulated to be indicative of changes expected over the long term. A stable isotope infusion combined with sampling of breath, blood, and muscle was used to determine the rate of whole body protein synthesis in 12 older adults. Intracellular signalling for mitochondrial and whole body protein synthesis was examined using RT-quantitative PCR and Western blotting in eleven young adults. The rate of post-exercise whole body protein synthesis was 19% greater over the first four hours of post-exercise recovery, in subjects receiving a protein-plus-carbohydrate drink immediately after a bout of cycling than in those receiving a carbohydrate-only drink (p = 0.001). The same trend was revealed in signalling for whole body protein synthesis and the abundance of cytochrome c, a mitochondrial protein, although these results were not statistically significant (p = 0.2). In contrast there was a strong, albeit also statistically insignificant, tendency for signalling for mitochondrial protein synthesis to be higher in the skeletal muscle of subjects receiving a carbohydrate-only drink after a bout of cycling (p = 0.06). The exercise and feeding intervention described in this thesis may provide a means to enhance the rate of mitochondrial protein synthesis in older individuals and, in so doing, improve the quality of their old age.
| Identifer | oai:union.ndltd.org:ADTP/278780 |
| Date | January 2009 |
| Creators | Murphy, Cheryl |
| Publisher | ResearchSpace@Auckland |
| Source Sets | Australiasian Digital Theses Program |
| Detected Language | English |
| Rights | Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated., http://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm, Copyright: The author |
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