AJP - Endo Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Endocrinol Metab 279: E275-E283, 2000;
0193-1849/00 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (10)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by St. Amand, T. A.
Right arrow Articles by Heigenhauser, G. J. F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by St. Amand, T. A.
Right arrow Articles by Heigenhauser, G. J. F.
Vol. 279, Issue 2, E275-E283, August 2000

Pyruvate overrides inhibition of PDH during exercise after a low-carbohydrate diet

Timothy A. St. Amand1, Lawrence L. Spriet2, Norman L. Jones1, and George J. F. Heigenhauser1

1 Department of Medicine, McMaster University, Hamilton, Ontario L8S 3Z5; and 2 Department of Human Biology and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada N1G 2W1

The effects of carbohydrate deprivation on the regulation of pyruvate dehydrogenase (PDH) were studied at rest and during moderate-intensity exercise. An inhibitory effect of a chronic low-carbohydrate diet (LCD) on the active form of PDH (PDHa) mediated by a stable increase in PDH kinase (PDHK) activity has recently been reported (Peters SJ, Howlett RA, St. Amand TA, Heigenhauser GJF, and Spriet LL. Am J Physiol Endocrinol Metab 275: E980-E986, 1998.). In the present study, seven males cycled at 65% maximal O2 uptake for 30 min after a 6-day LCD. Exercise was repeated 1 wk later after a mixed diet (MD). Muscle biopsies were sampled from the vastus lateralis at rest and at 2 and 30 min of exercise. At rest, PDHa activity (0.18 ± 0.04 vs. 0.63 ± 0.18 mmol · min-1 · kg wet wt-1), muscle glycogen content (310.2 ± 36.9 vs. 563.9 ± 32.6 mmol/kg dry wt), and muscle lactate content (2.6 ± 0.3 vs. 4.2 ± 0.6 mmol/kg dry wt) were significantly lower after the LCD. Resting muscle acetyl-CoA (10.8 ± 1.9 vs. 7.4 ± 0.8 µmol/kg dry wt) and acetylcarnitine (5.3 ± 1.4 vs. 1.6 ± 0.3 mmol/kg dry wt) contents were significantly elevated after the LCD. During exercise, PDHa, glycogenolytic rate (LCD 5.8 ± 0.4 vs. MD 6.9 ± 0.2 mmol · min-1 · kg dry wt-1 ), and muscle concentrations of acetylcarnitine, pyruvate, and lactate increased to the same extent in both conditions. The results of the present study suggest that inhibition of resting PDH by elevated PDHK activity after a LCD may be overridden by the availability of muscle pyruvate during exercise.

carbohydrate and fat metabolism; glycogen phosphorylase


This article has been cited by other articles:


Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
T. Stellingwerff, L. L. Spriet, M. J. Watt, N. E. Kimber, M. Hargreaves, J. A. Hawley, and L. M. Burke
Decreased PDH activation and glycogenolysis during exercise following fat adaptation with carbohydrate restoration
Am J Physiol Endocrinol Metab, February 1, 2006; 290(2): E380 - E388.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
M. P. Harber, S. Schenk, A. L. Barkan, and J. F. Horowitz
Alterations in carbohydrate metabolism in response to short-term dietary carbohydrate restriction
Am J Physiol Endocrinol Metab, August 1, 2005; 289(2): E306 - E312.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
T. L. Pehleman, S. J. Peters, G. J. F. Heigenhauser, and L. L. Spriet
Enzymatic regulation of glucose disposal in human skeletal muscle after a high-fat, low-carbohydrate diet
J Appl Physiol, January 1, 2005; 98(1): 100 - 107.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
D. Constantin-Teodosiu, N. S Peirce, J. Fox, and P. L Greenhaff
Muscle pyruvate availability can limit the flux, but not activation, of the pyruvate dehydrogenase complex during submaximal exercise in humans
J. Physiol., December 1, 2004; 561(2): 647 - 655.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online