Abstract
Oxidative metabolism has reactive oxygen species (ROS) as unavoidable by-products, and the damage ROS inflicts on DNA, proteins and lipids is considered to be a major agent of senescence. Increasing reproductive effort accelerates senescence, but whether reproductive effort is increased at the expense of protection against oxidative damage has not yet been tested. We manipulated reproductive effort in zebra finches through brood size manipulation and measured the activity of two major antioxidant enzymes (superoxide dismutase (SOD) and glutathione peroxidase (GPx)) in the pectoral muscle after 19-20 days of brood rearing. Oxidative stress is reflected by the balance between oxidative protection and ROS exposure, and we therefore scaled SOD and GPx activity to daily energy expenditure (DEE) as an index of ROS production. SOD and GPx activity decreased with increasing brood size by 28% and 24%, respectively. This effect was identical in the two sexes, but arose in different ways: males did not change their DEE, but had lower absolute enzyme activity, and females increased their DEE, but did not change absolute enzyme activity. This result suggests that senescence acceleration by increased reproductive effort is at least in part mediated by oxidative stress.
Full Text
The Full Text of this article is available as a PDF (104.6 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Barja Gustavo. Rate of generation of oxidative stress-related damage and animal longevity. Free Radic Biol Med. 2002 Nov 1;33(9):1167–1172. doi: 10.1016/s0891-5849(02)00910-3. [DOI] [PubMed] [Google Scholar]
- Beckman K. B., Ames B. N. The free radical theory of aging matures. Physiol Rev. 1998 Apr;78(2):547–581. doi: 10.1152/physrev.1998.78.2.547. [DOI] [PubMed] [Google Scholar]
- Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1006/abio.1976.9999. [DOI] [PubMed] [Google Scholar]
- Finkel T., Holbrook N. J. Oxidants, oxidative stress and the biology of ageing. Nature. 2000 Nov 9;408(6809):239–247. doi: 10.1038/35041687. [DOI] [PubMed] [Google Scholar]
- Golden Tamara R., Hinerfeld Douglas A., Melov Simon. Oxidative stress and aging: beyond correlation. Aging Cell. 2002 Dec;1(2):117–123. doi: 10.1046/j.1474-9728.2002.00015.x. [DOI] [PubMed] [Google Scholar]
- Hamilton W. D. The moulding of senescence by natural selection. J Theor Biol. 1966 Sep;12(1):12–45. doi: 10.1016/0022-5193(66)90184-6. [DOI] [PubMed] [Google Scholar]
- Holmes D. J., Flückiger R., Austad S. N. Comparative biology of aging in birds: an update. Exp Gerontol. 2001 Apr;36(4-6):869–883. doi: 10.1016/s0531-5565(00)00247-3. [DOI] [PubMed] [Google Scholar]
- Kirkwood T. B., Austad S. N. Why do we age? Nature. 2000 Nov 9;408(6809):233–238. doi: 10.1038/35041682. [DOI] [PubMed] [Google Scholar]
- Kirkwood T. B., Rose M. R. Evolution of senescence: late survival sacrificed for reproduction. Philos Trans R Soc Lond B Biol Sci. 1991 Apr 29;332(1262):15–24. doi: 10.1098/rstb.1991.0028. [DOI] [PubMed] [Google Scholar]
- Loft S., Velthuis-te Wierik E. J., van den Berg H., Poulsen H. E. Energy restriction and oxidative DNA damage in humans. Cancer Epidemiol Biomarkers Prev. 1995 Jul-Aug;4(5):515–519. [PubMed] [Google Scholar]
- López-Torres M., Pérez-Campo R., Barja de Quiroga G. Effect of natural ageing and antioxidant inhibition on liver antioxidant enzymes, glutathione system, peroxidation, and oxygen consumption in Rana perezi. J Comp Physiol B. 1991;160(6):655–661. doi: 10.1007/BF00571264. [DOI] [PubMed] [Google Scholar]
- Parkes T. L., Elia A. J., Dickinson D., Hilliker A. J., Phillips J. P., Boulianne G. L. Extension of Drosophila lifespan by overexpression of human SOD1 in motorneurons. Nat Genet. 1998 Jun;19(2):171–174. doi: 10.1038/534. [DOI] [PubMed] [Google Scholar]
- Perez-Campo R., López-Torres M., Cadenas S., Rojas C., Barja G. The rate of free radical production as a determinant of the rate of aging: evidence from the comparative approach. J Comp Physiol B. 1998 Apr;168(3):149–158. doi: 10.1007/s003600050131. [DOI] [PubMed] [Google Scholar]
- Selman C., McLaren J. S., Himanka M. J., Speakman J. R. Effect of long-term cold exposure on antioxidant enzyme activities in a small mammal. Free Radic Biol Med. 2000 Apr 15;28(8):1279–1285. doi: 10.1016/s0891-5849(00)00263-x. [DOI] [PubMed] [Google Scholar]
- von Schantz T., Bensch S., Grahn M., Hasselquist D., Wittzell H. Good genes, oxidative stress and condition-dependent sexual signals. Proc Biol Sci. 1999 Jan 7;266(1414):1–12. doi: 10.1098/rspb.1999.0597. [DOI] [PMC free article] [PubMed] [Google Scholar]