Am J Physiol Cell Physiol Watch the video to learn how APS reaches out to developing nations.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Cell Physiol 267: C55-C66, 1994;
0363-6143/94 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
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
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Michel, R. N.
Right arrow Articles by Lowry, O. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Michel, R. N.
Right arrow Articles by Lowry, O. H.

AJP - Cell Physiology, Vol 267, Issue 1 C55-C66, Copyright © 1994 by American Physiological Society

ARTICLES

Effects of tetrodotoxin-induced neural inactivation on single muscle fiber metabolic enzymes

R. N. Michel, G. Cowper, M. M. Chi, J. K. Manchester, H. Falter and O. H. Lowry
School of Human Movement, Laurentian University, Sudbury, Ontario, Canada.

Selected enzymes were measured in mixed-fiber bundles and individual fibers from rat plantaris (PL) and soleus (Sol) muscles that had undergone either 2 wk of tetrodotoxin (TTX) inactivation of the sciatic nerve, a sham operation, or were contralateral to the TTX limb. TTX disuse caused severe wasting of PL (46%) and Sol (26%) muscles and of single fibers (50% and 40%, respectively). TTX PL and Sol also had reduced (50%) glycogen content. In TTX, PL, and Sol macro samples and single fibers, the activities (mol.h-1.kg dry wt-1) of hexokinase, glycogen phosphorylase, and lactate dehydrogenase were higher, lower, and unchanged, respectively, compared with controls. Single-fiber data showed that these changes occurred in all fibers. In TTX PL macro samples, activities of glycerol-3-phosphate dehydrogenase (GPDH), pyruvate kinase (PK), malate dehydrogenase (MDH), citrate synthase (CS), beta-hydroxyacyl-CoA dehydrogenase (BOAC), and thiolase were, or tended to be, lower. Single-fiber data showed a disappearance of high-oxidative moderate glycolytic fibers (i.e., usually fast-twitch oxidative in control) and the appearance of more fibers with a metabolic enzyme profile approaching that of control slow-oxidative fibers. In TTX Sol macro samples, GPDH and PK tended to be higher, and thiolase, BOAC, CS, and MDH lower. Single-fiber data corroborated these findings and suggested the appearance of fast fibers with downregulated oxidative enzyme profiles. Our results suggest that neuromuscular activity is a major, but not the sole, determinant of the size and metabolic heterogeneity that exists in muscle cells.


This article has been cited by other articles:


Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
S.-Y. Yang and X.-Y. He
Re: Hadh2 and 3-hydroxyacyl-CoA dehydrogenase
Am J Physiol Endocrinol Metab, October 1, 2008; 295(4): E987 - E987.
[Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
B. Cormery, F. Pons, J.-F. Marini, and P. F. Gardiner
Myosin heavy chains in fibers of TTX-paralyzed rat soleus and medial gastrocnemius muscles
J Appl Physiol, January 1, 2000; 88(1): 66 - 76.
[Abstract] [Full Text] [PDF]


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