AJP - Endo AJP: Heart and Circulatory Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     


Am J Physiol Endocrinol Metab 296: E1400-E1408, 2009. First published March 24, 2009; doi:10.1152/ajpendo.90913.2008
0193-1849/09 $8.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
296/6/E1400    most recent
90913.2008v1
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 PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Google Scholar
Right arrow Articles by Williams, D. B.
Right arrow Articles by Wright, D. C.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Williams, D. B.
Right arrow Articles by Wright, D. C.

TRANSLATIONAL PHYSIOLOGY

Muscle-specific differences in the response of mitochondrial proteins to β-GPA feeding: an evaluation of potential mechanisms

Deon B. Williams,1 Lindsey N. Sutherland,1 Marc R. Bomhof,1 Susan A. U. Basaraba,1 A. Brianne Thrush,2 David J. Dyck,2 Catherine J. Field,1 and David C. Wright1

1Alberta Diabetes Institute, University of Alberta, Edmonton; and 2Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada

Submitted 13 November 2008 ; accepted in final form 22 March 2009

β-Guanadinopropionic acid (β-GPA) feeding leads to reductions in skeletal muscle phosphagen concentrations and has been used as a tool with which to study the effects of energy charge on skeletal muscle metabolism. Supplementing standard rodent diets with β-GPA leads to increases in mitochondrial enzyme content in fast but not slow-twitch muscles from male rats. Given this apparent discrepancy between muscle types we used β-GPA feeding as a model to study signaling pathways involved in mitochondrial biogenesis. We hypothesized that β-GPA feeding would result in a preferential activation of p38 MAPK and AMPK signaling and reductions in RIP140 protein content in triceps but not soleus muscle. Despite similar reductions in high-energy phosphate concentrations, 6 wk of β-GPA feeding led to increases in mitochondrial proteins in triceps but not soleus muscles. Differences in the response of mitochondrial proteins to β-GPA feeding did not seem to be related to a differential activation of p38 MAPK and AMPK signaling pathways or discrepancies in the induction of PPAR{gamma} coactivator (PGC)-1{alpha} and -1β. The protein content and expression of the nuclear corepressor RIP140 was reduced in triceps but not soleus muscle. Collectively our results indicate that chronic reductions in high-energy phosphates lead to the activation of p38 MAPK and AMPK signaling and increases in the expression of PGC-1{alpha} and -1β in both soleus and triceps muscles. The lack of an effect of β-GPA feeding on mitochondrial proteins in the soleus muscles could be related to a fiber type-specific effect of β-GPA on RIP140 protein content.

β-guanadinopropionic acid; peroxisome proliferator-activated receptor-{gamma} coactivator-1{alpha}; skeletal muscle; rat; kinase; RIP140



Address for reprint requests and other correspondence: D. C. Wright, Alberta Diabetes Institute, 4126C HRIF East, Univ. of Alberta, Edmonton, Alberta, Canada T6G 2E1 (E-mail: dcw3{at}ualberta.ca)







HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online
Copyright © 2009 by the American Physiological Society.