scholarly journals Fiber Type-Specific Localization of Monocarboxylate Transporters MCT1 and MCT4 in Rat Skeletal Muscle

2004 ◽  
Vol 51 (3/4) ◽  
pp. 253-261 ◽  
Author(s):  
MASATOSHI KOBAYASHI
Keyword(s):  
Skeletal Muscle ◽  
Fiber Type ◽  
Monocarboxylate Transporters ◽  
Rat Skeletal Muscle ◽  
Specific Localization

No limiting role for glycogenin in determining maximal attainable glycogen levels in rat skeletal muscle

2000 ◽  
Vol 278 (3) ◽  
pp. E398-E404 ◽  
Author(s):  
Bo Falck Hansen ◽  
Wim Derave ◽  
Pia Jensen ◽  
Erik A. Richter
Keyword(s):  
Skeletal Muscle ◽  
Protein Level ◽  
Fiber Type ◽  
Rat Skeletal Muscle ◽  
Protein Core ◽  
Protein Levels ◽  
Very High ◽  
White Gastrocnemius

We examined whether the protein level and/or activity of glycogenin, the protein core upon which glycogen is synthesized, is limiting for maximal attainable glycogen levels in rat skeletal muscle. Glycogenin activity was 27.5 ± 1.4, 34.7 ± 1.7, and 39.7 ± 1.3 mU/mg protein in white gastrocnemius, red gastrocnemius, and soleus muscles, respectively. A similar fiber type dependency of glycogenin protein levels was seen. Neither glycogenin protein level nor the activity of glycogenin correlated with previously determined maximal attainable glycogen levels, which were 69.3 ± 5.8, 137.4 ± 10.1, and 80.0 ± 5.4 μmol/g wet wt in white gastrocnemius, red gastrocnemius, and soleus muscles, respectively. In additional experiments, rats were exercise trained by swimming, which resulted in a significant increase in the maximal attainable glycogen levels in soleus muscles (∼25%). This increase in maximal glycogen levels was not accompanied by an increase in glycogenin protein level or activity. Furthermore, even in the presence of very high glycogen levels (∼170 μmol/g wet wt), ∼30% of the total glycogen pool continued to be present as unsaturated glycogen molecules (proglycogen). Therefore, it is concluded that glycogenin plays no limiting role for maximal attainable glycogen levels in rat skeletal muscle.

scholarly journals Acetylcholine and insulin‐mediated vasodilation in feed arteries and arterioles of rat skeletal muscle of different fiber type composition

2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Jaume Padilla ◽  
Nathan T Jenkins ◽  
Jeffrey S Martin ◽  
Jacqueline M Crissey ◽  
Shawn B Bender ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fiber Type ◽  
Rat Skeletal Muscle ◽  
Fiber Type Composition ◽  
Type Composition ◽  
Feed Arteries

VEGF Protein Expression in Rat Skeletal Muscle is Fiber-type Dependent

2007 ◽  
Vol 39 (Supplement) ◽  
pp. S286
Author(s):  
Matthew J. Wessner ◽  
Paticia S. Sexton ◽  
William L. Sexton
Keyword(s):  
Skeletal Muscle ◽  
Protein Expression ◽  
Fiber Type ◽  
Rat Skeletal Muscle ◽  
Vegf Protein

Phosphate uptake in rat skeletal muscle is reduced during isometric contractions

2004 ◽  
Vol 97 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Kirk A. Abraham ◽  
Ronald L. Terjung
Keyword(s):  
Skeletal Muscle ◽  
Inorganic Phosphate ◽  
Phosphate Uptake ◽  
Specific Activity ◽  
Fiber Type ◽  
Rat Skeletal Muscle ◽  
Energy Expenditures ◽  
Contraction Duration ◽  
Uptake Rates ◽  
White Gastrocnemius

During contractions, there is a net efflux of phosphate from skeletal muscle, likely because of an elevated intracellular inorganic phosphate (Pi) concentration. Over time, contracting muscle could incur a substantial phosphate deficit unless Pi uptake rates were increased during contractions. We used the perfused rat hindquarter preparation to assess [32P]Pi uptake rates in muscles at rest or over a range of energy expenditures during contractions at 0.5, 3, or 5 Hz for 30 min. Pi uptake rates were reduced during contractions in a pattern that was dependent on contraction frequency and fiber type. In soleus and red gastrocnemius, [32P]Pi uptake rates declined by ∼25% at 0.5 Hz and 50–60% at 3 and 5 Hz. Uptake rates in white gastrocnemius decreased by 65–75% at all three stimulation frequencies. These reductions in Pi uptake are not likely confounded by changes in precursor [32P]Pi specific activity in the interstitium. In soleus and red gastrocnemius, declines in Pi uptake rates were related to energy expenditure over the contraction duration. These data imply that Pi uptake in skeletal muscle is acutely modulated during contractions and that decreases in Pi uptake rates, in combination with expected increases in Pi efflux, exacerbate the net loss of phosphate from the cell. Enhanced uptake of Pi must subsequently occur because skeletal muscle typically maintains a relatively constant total phosphate pool.

scholarly journals Fiber type effects on contraction-stimulated glucose uptake and GLUT4 abundance in single fibers from rat skeletal muscle

2015 ◽  
Vol 308 (3) ◽  
pp. E223-E230 ◽  
Author(s):  
Carlos M. Castorena ◽  
Edward B. Arias ◽  
Naveen Sharma ◽  
Jonathan S. Bogan ◽  
Gregory D. Cartee
Keyword(s):  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Glucose Transporter ◽  
Fiber Type ◽  
Fiber Types ◽  
Rat Skeletal Muscle ◽  
Single Fibers ◽  
Mhc Iia ◽  
Mhc Iib ◽  
Filamin C

To fully understand skeletal muscle at the cellular level, it is essential to evaluate single muscle fibers. Accordingly, the major goals of this study were to determine if there are fiber type-related differences in single fibers from rat skeletal muscle for: 1) contraction-stimulated glucose uptake and/or 2) the abundance of GLUT4 and other metabolically relevant proteins. Paired epitrochlearis muscles isolated from Wistar rats were either electrically stimulated to contract (E-Stim) or remained resting (No E-Stim). Single fibers isolated from muscles incubated with 2-deoxy-d-[3H]glucose (2-DG) were used to determine fiber type [myosin heavy chain (MHC) isoform protein expression], 2-DG uptake, and abundance of metabolically relevant proteins, including the GLUT4 glucose transporter. E-Stim, relative to No E-Stim, fibers had greater ( P < 0.05) 2-DG uptake for each of the isolated fiber types (MHC-IIa, MHC-IIax, MHC-IIx, MHC-IIxb, and MHC-IIb). However, 2-DG uptake for E-Stim fibers was not significantly different among these five fiber types. GLUT4, tethering protein containing a UBX domain for GLUT4 (TUG), cytochrome c oxidase IV (COX IV), and filamin C protein levels were significantly greater ( P < 0.05) in MHC-IIa vs. MHC-IIx, MHC-IIxb, or MHC-IIb fibers. TUG and COX IV in either MHC-IIax or MHC-IIx fibers exceeded values for MHC-IIxb or MHC-IIb fibers. GLUT4 levels for MHC-IIax fibers exceeded MHC-IIxb fibers. GLUT4, COX IV, filamin C, and TUG abundance in single fibers was significantly ( P < 0.05) correlated with each other. Differences in GLUT4 abundance among the fiber types were not accompanied by significant differences in contraction-stimulated glucose uptake.

Fiber type-related changes in rat skeletal muscle calcium homeostasis during aging and restoration by growth hormone

2006 ◽  
Vol 21 (2) ◽  
pp. 372-380 ◽  
Author(s):  
Bodvael Fraysse ◽  
Jean-François Desaphy ◽  
Jean-François Rolland ◽  
Sabata Pierno ◽  
Antonella Liantonio ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Growth Hormone ◽  
Calcium Homeostasis ◽  
Fiber Type ◽  
Rat Skeletal Muscle ◽  
Muscle Calcium
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