Faculty Collaboration Database

Substrate and enzyme profile of fast and slow skeletal muscle fibers in rhesus monkeys. J Appl Physiol (1985) 1999 Jan;86(1):335-40

Date

01/14/1999

Pubmed ID

9887148

DOI

10.1152/jappl.1999.86.1.335

Scopus ID

2-s2.0-0032958710 (requires institutional sign-in at Scopus site)   8 Citations

Abstract

Results from the Russian Cosmos program suggest that the rhesus monkey is an excellent model for studying weightlessness-induced changes in muscle function. Consequently, the purpose of this investigation was to establish the resting levels of selected substrate and enzymes in individual slow- and fast-twitch muscle fibers of the rhesus monkey. A second objective was to determine the effect of an 18-day sit in the Spacelab experiment-support primate facility [Experimental System for the Orbiting Primate (ESOP)]. Muscle biopsies of the soleus and medial gastrocnemius muscles were obtained 1 mo before and immediately after an 18-day ESOP sit. The biopsies were freeze-dried, and individual fibers were isolated and assayed for the substrates glycogen and lactate and for the high-energy phosphates ATP and phosphocreatine. Fiber enzyme activity was also determined for the glycolytic enzymes phosphofructokinase and lactate dehydrogenase (LDH) and for the oxidative markers 3-hydroxyacyl-CoA dehydrogenase (beta-OAC) and citrate synthase. Consistent with other species, the fast type II fibers contained higher glycogen content than did the slow type I fibers. The ESOP sit had no significant effects on the metabolic profile of the slow fibers of either muscle or the fast fibers of the soleus. However, the fast gastrocnemius fibers showed a significant decline in phosphocreatine and an increase in lactate. Also, similar to other species, the fast fibers contained significantly higher LDH activities and lower 3-hydroxyacyl-CoA dehydrogenase activities. For the muscle enzymes, the quantitatively most important effect of the ESOP sit occurred with LDH where activities increased in all fiber types postsit except the slow type I fiber of the medial gastrocnemius.

Author List

Grichko VP, Gettelman GJ, Widrick JJ, Fitts RH

Author

Robert Fitts PhD Professor in the Biological Sciences department at Marquette University

MESH terms used to index this publication - Major topics in bold

Adenosine Triphosphate
Animals
Citrate (si)-Synthase
Electrophoresis, Polyacrylamide Gel
Glycogen
L-Lactate Dehydrogenase
Lactic Acid
Macaca mulatta
Male
Muscle Fibers, Fast-Twitch
Muscle Fibers, Slow-Twitch
Myosin Heavy Chains
Phosphocreatine
Phosphofructokinase-1