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

This Article Full Text Free Full Text (PDF) Free Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Tupling, A. R. Articles by Ouyang, J. Search for Related Content PubMed PubMed Citation Articles by Tupling, A. R. Articles by Ouyang, J.

Paradoxical effects of prior activity on human sarcoplasmic reticulum Ca²⁺-ATPase response to exercise

Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1

Submitted 31 May 2002 ; accepted in final form 26 March 2003

To investigate the effects of intermittent heavy exercise (HE) on sarcoplasmic reticulum (SR) maximal Ca²⁺-ATPase activity (V_max) and Ca²⁺ uptake, a continuous two-stage standardized cycling test was performed before and after HE by untrained men [peak aerobic power (O_{2 peak}) = 42.9 ± 2.7 ml · kg^-1 · min^-1]. The HE consisted of 16 bouts of cycling performed for 6 min each hour at 90% O_{2 peak}. Tissue was obtained from the vastus lateralis by needle biopsy before and during each cycle test. Before HE, reductions (P < 0.05; µmol · g protein^-1 · min^-1) of 16 and 31% were observed in V_max and Ca²⁺ uptake, respectively, after 40 min of the standardized test. Resting V_max and Ca²⁺ uptake were depressed (P < 0.05) by 19 and 30%, respectively, when measured 36–48 h after HE. During the standardized test, after HE, V_max increased (P < 0.05) by 20%, whereas no change was observed in Ca²⁺ uptake. The HE protocol resulted in small increases (P < 0.05) and decreases (P < 0.05) in sarco(endo)plasmic reticulum Ca²⁺-ATPase (SERCA) 2a and SERCA1 expression, respectively, as determined by Western blotting techniques. These results indicate that SR Ca²⁺-sequestering function in response to a prolonged exercise test depends on prior activity status, such that rested muscles exhibit a decrease and prior exercised muscles, an increase in Ca²⁺-ATPase activity. Moreover, it appears that changes in SERCA content can occur in response to a sustained session of intermittent exercise.

Ca²⁺ sequestering; continuous exercise; fatigue; vastus lateralis; SERCA isoforms

This article has been cited by other articles:

				T. A. Duhamel, H. J. Green, R. D. Stewart, K. P. Foley, I. C. Smith, and J. Ouyang Muscle metabolic, SR Ca2+-cycling responses to prolonged cycling, with and without glucose supplementation J Appl Physiol, December 1, 2007; 103(6): 1986 - 1998. [Abstract] [Full Text] [PDF]

				T. A. Duhamel, R. D. Stewart, A. R. Tupling, J. Ouyang, and H. J. Green Muscle sarcoplasmic reticulum calcium regulation in humans during consecutive days of exercise and recovery J Appl Physiol, October 1, 2007; 103(4): 1212 - 1220. [Abstract] [Full Text] [PDF]

				H. J. Green, T. A. Duhamel, G. P. Holloway, J. W. Moule, J. Ouyang, D. Ranney, and A. R. Tupling Muscle Na+-K+-ATPase response during 16 h of heavy intermittent cycle exercise Am J Physiol Endocrinol Metab, August 1, 2007; 293(2): E523 - E530. [Abstract] [Full Text] [PDF]

				T. A. Duhamel, H. J. Green, J. G. Perco, and J. Ouyang Comparative effects of a low-carbohydrate diet and exercise plus a low-carbohydrate diet on muscle sarcoplasmic reticulum responses in males Am J Physiol Cell Physiol, October 1, 2006; 291(4): C607 - C617. [Abstract] [Full Text] [PDF]

				T. A. Duhamel, J. G. Perco, and H. J. Green Manipulation of dietary carbohydrates after prolonged effort modifies muscle sarcoplasmic reticulum responses in exercising males Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2006; 291(4): R1100 - R1110. [Abstract] [Full Text] [PDF]

				T. A. Duhamel, H. J. Green, J. G. Perco, and J. Ouyang Effects of prior exercise and a low-carbohydrate diet on muscle sarcoplasmic reticulum function during cycling in women J Appl Physiol, September 1, 2006; 101(3): 695 - 706. [Abstract] [Full Text] [PDF]

				G. P. Holloway, H. J. Green, and A. R. Tupling Differential effects of repetitive activity on sarcoplasmic reticulum responses in rat muscles of different oxidative potential Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2006; 290(2): R393 - R404. [Abstract] [Full Text] [PDF]

				G. P. Holloway, H. J. Green, T. A. Duhamel, S. Ferth, J. W. Moule, J. Ouyang, and A. R. Tupling Muscle sarcoplasmic reticulum Ca2+ cycling adaptations during 16 h of heavy intermittent cycle exercise J Appl Physiol, September 1, 2005; 99(3): 836 - 843. [Abstract] [Full Text] [PDF]

				H. J. Green, T. A. Duhamel, S. Ferth, G. P. Holloway, M. M. Thomas, A. R. Tupling, S. M. Rich, and J. E. Yau Reversal of muscle fatigue during 16 h of heavy intermittent cycle exercise J Appl Physiol, December 1, 2004; 97(6): 2166 - 2175. [Abstract] [Full Text] [PDF]