HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Cited by other online articles Google Scholar Articles by Lal, S. B. Articles by Harper, M.-E. Articles citing this Article PubMed PubMed Citation Articles by Lal, S. B. Articles by Harper, M.-E.

Effects of Caloric Restriction on Skeletal Muscle Mitochondrial Proton Leak in Aging Rats

^a Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario, Canada
^b Wisconsin Regional Primate Research Center, University of Wisconsin, Madison
^c Department of Medicine, University of Wisconsin, and Veterans Administration Geriatric Research, Education and Clinical Center, Madison

Mary-Ellen Harper, Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada E-mail: mharper{at}uottawa.ca.

Decision Editor: John A. Faulkner, PhD

Long-term caloric restriction (CR) retards aging processes and increases maximum life span. We investigated the influence of CR on mitochondrial proton leaks in rat skeletal muscle. Because CR lowers oxidative damage to mitochondrial membrane lipids and proteins, we hypothesized that leak would be lower in mitochondria from old CR rats than in age-matched controls. Three groups (n = 12) were studied: 4-month-old "young" control rats (body weight: 404 g ± 7 SEM), 33-month-old CR rats (body weight: 262 g ± 3), and 33-month-old control rats (body weight: 446 g ± 5). CR rats received 67% of the energy intake of old control rats, with adequate intakes of all essential nutrients. Maximum leak-dependent O₂ consumption (State 4) was 23% lower in CR rats than in age-matched controls, whereas protonmotive force values were similar, supporting our hypothesis. The overall kinetics of leak were similar between the two groups of old rats; in the young, kinetics indicated higher protonmotive force values. The latter indication is consistent with aging-induced alterations in proton leak kinetics that are independent of dietary intervention. There was no influence of age or diet on serum T₄ level, whereas T₃ was lower in young than in old control rats. These results support and extend the oxidative stress hypothesis of aging.

This article has been cited by other articles: (Search Google Scholar for Other Citing Articles)

				L. Bevilacqua, J. J. Ramsey, K. Hagopian, R. Weindruch, and M.-E. Harper Long-term caloric restriction increases UCP3 content but decreases proton leak and reactive oxygen species production in rat skeletal muscle mitochondria Am J Physiol Endocrinol Metab, September 1, 2005; 289(3): E429 - E438. [Abstract] [Full Text] [PDF]

				A. J. Lambert and B. J. Merry Effect of caloric restriction on mitochondrial reactive oxygen species production and bioenergetics: reversal by insulin Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2004; 286(1): R71 - 79. [Abstract] [Full Text]

				D. Julian and C. Leeuwenburgh Linkage between insulin and the free radical theory of aging Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2004; 286(1): R20 - 21. [Full Text]

				J. E. Morley Editorial: Citations, Impact Factor, and the Journal J. Gerontol. A Biol. Sci. Med. Sci., December 1, 2002; 57(12): M765 - 769. [Full Text] [PDF]

				R. Weindruch, K. P. Keenan, J. M. Carney, G. Fernandes, R. J. Feuers, R. A. Floyd, J. B. Halter, J. J. Ramsey, A. Richardson, G. S. Roth, and S. R. Spindler Caloric Restriction Mimetics: Metabolic Interventions J. Gerontol. A Biol. Sci. Med. Sci., March 1, 2001; 56(90001): 20 - 33. [Abstract] [Full Text] [PDF]

				A. G Madapallimattam, L. Law, and K. N Jeejeebhoy Effect of hypoenergetic feeding on muscle oxidative phosphorylation and mitochondrial complex I-IV activities in rats Am. J. Clinical Nutrition, November 1, 2002; 76(5): 1031 - 1039. [Abstract] [Full Text] [PDF]

				R. N. Butler, M. Fossel, S. M. Harman, C. B. Heward, S. J. Olshansky, T. T. Perls, D. J. Rothman, S. M. Rothman, H. R. Warner, M. D. West, and W. E. Wright Is There an Antiaging Medicine? J. Gerontol. A Biol. Sci. Med. Sci., September 1, 2002; 57(9): B333 - 338. [Abstract] [Full Text] [PDF]