|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
It has been proposed that mitochondrial uncoupling protein 3 (UCP3) behaves as an uncoupler of oxidative phosphorylation. In a cross-sectional study, UCP3 protein levels were found to be lower in all fibre types of endurance-trained cyclists as compared to healthy controls. This decrease was greatest in the type I oxidative fibres, and it was hypothesised that this may be due to the preferential recruitment of these fibres during endurance training. To test this hypothesis, we compared the effects of 6 weeks of endurance (ETr) and sprint (STr) running training on UCP3 mRNA expression and fibre-type protein content using real-time PCR and immunofluorescence techniques, respectively. UCP3 mRNA and protein levels were downregulated similarly in ETr and STr (UCP3 mRNA: by 65 and 50 %, respectively; protein: by 30 and 27 %, respectively). ETr significantly reduced UCP3 protein content in type I, IIa and IIx muscle fibres by 54, 29 and 16 %, respectively. STr significantly reduced UCP3 protein content in type I, IIa and IIx muscle fibres by 24, 31 and 26 %, respectively. The fibre-type reductions in UCP3 due to ETr, but not STr, were significantly different from each other, with the effect being greater in type I than in type IIa, and in type IIa than in type IIx fibres. As a result, compared to STr, ETr reduced UCP3 expression significantly more in fibre type I and significantly less in fibre types IIx. This suggests that the more a fibre is recruited, the more it adapts to training by a decrease in its UCP3 expression. In addition, the more a fibre type depends on fatty acidoxidation and oxidative phosphorylation, the more it responds to ETr by a decrease in its UCP3 content.
This article has been cited by other articles:
![]() |
H. R. Gosker, P. Schrauwen, R. Broekhuizen, M. K. C. Hesselink, E. Moonen-Kornips, K. A. Ward, F. M. E. Franssen, E. F. M. Wouters, and A. M. W. J. Schols Exercise training restores uncoupling protein-3 content in limb muscles of patients with chronic obstructive pulmonary disease Am J Physiol Endocrinol Metab, May 1, 2006; 290(5): E976 - E981. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Schrauwen, M. Mensink, G. Schaart, E. Moonen-Kornips, J.-P. Sels, E. E. Blaak, A. P. Russell, and M. K. C. Hesselink Reduced Skeletal Muscle Uncoupling Protein-3 Content in Prediabetic Subjects and Type 2 Diabetic Patients: Restoration by Rosiglitazone Treatment J. Clin. Endocrinol. Metab., April 1, 2006; 91(4): 1520 - 1525. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. B. Taylor, J. D. Lamb, R. W. Hurst, D. G. Chesser, W. J. Ellingson, L. J. Greenwood, B. B. Porter, S. T. Herway, and W. W. Winder Endurance training increases skeletal muscle LKB1 and PGC-1{alpha} protein abundance: effects of time and intensity Am J Physiol Endocrinol Metab, December 1, 2005; 289(6): E960 - E968. [Abstract] [Full Text] [PDF] |
||||
![]() |
K De Bock, E. A Richter, A. P Russell, B. O Eijnde, W Derave, M Ramaekers, E Koninckx, B Leger, J Verhaeghe, and P Hespel Exercise in the fasted state facilitates fibre type-specific intramyocellular lipid breakdown and stimulates glycogen resynthesis in humans J. Physiol., April 15, 2005; 564(2): 649 - 660. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. W. Mitchell, N. Turner, A. J. Hulbert, P. L. Else, J. A. Hawley, J. S. Lee, C. R. Bruce, and S. J. Blanksby Exercise alters the profile of phospholipid molecular species in rat skeletal muscle J Appl Physiol, November 1, 2004; 97(5): 1823 - 1829. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Ljubicic, P. J. Adhihetty, and D. A. Hood Role of UCP3 in state 4 respiration during contractile activity-induced mitochondrial biogenesis J Appl Physiol, September 1, 2004; 97(3): 976 - 983. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. J. Mahoney, K. Carey, M.-H. Fu, R. Snow, D. Cameron-Smith, G. Parise, and M. A. Tarnopolsky Real-time RT-PCR analysis of housekeeping genes in human skeletal muscle following acute exercise Physiol Genomics, July 8, 2004; 18(2): 226 - 231. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |