Distribution of different fiber types in human skeletal muscles: Effects of aging studied in whole muscle cross sections

1983 ◽  
Vol 6 (8) ◽  
pp. 588-595 ◽  
Author(s):  
Jan Lexell ◽  
Karin Henriksson-Larsén ◽  
Bengt Winblad ◽  
Michael Sjöström
2007 ◽  
Vol 15 (3) ◽  
pp. 336-348 ◽  
Author(s):  
Florian Brunner ◽  
Annina Schmid ◽  
Ali Sheikhzadeh ◽  
Margareta Nordin ◽  
Jangwhon Yoon ◽  
...  

The authors conducted a systematic review of the literature for scientific articles in selected databases to determine the effects of aging on Type II muscle fibers in human skeletal muscles. They found that aging of Type II muscle fibers is primarily associated with a loss of fibers and a decrease in fiber size. Morphological changes with increasing age particularly included Type II fiber grouping. There is conflicting evidence regarding the change of proportion of Type II fibers. Type II muscle fibers seem to play an important role in the aging process of human skeletal muscles. According to this literature review, loss of fibers, decrease in size, and fiber-type grouping represent major quantitative changes. Because the process of aging involves various complex phenomena such as fiber-type coexpression, however, it seems difficult to assign those changes solely to a specific fiber type.


1986 ◽  
Vol 9 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Michael Sjöström ◽  
David Y. Downham ◽  
Jan Lexell

2018 ◽  
Vol 28 (1) ◽  
Author(s):  
Barbara Ravara ◽  
Valerio Gobbo ◽  
Damiana Incendi ◽  
Andrea Porzionato ◽  
Veronica Macchi ◽  
...  

The sternomastoid (SM) muscle in rodents is known to have a peculiar distribution of fiber types with a steep gradient from surface to deep region. We here further characterize this peculiar regional distribution by quantitative histochemical morphometrys. In Hematoxylin-Eosin (H-E) stained transverse cryosections harvested in the medial portion of the muscle we counted around 10.000 myofibers with a mean diameter of 51.3±12.6 (μm). Cryisections of the SM stained by SDH reaction clearly show two distinct regions, toward the deep surface of the muscle a 40% area that contains packed SDH-positive myofibers, while the remaining area of the SM toward the external surface presents a more checker-board appearance. On the other hand, in the deep region of SM type 1 (slow contracting) muscle fibers, caracterized by positive acidic ATPase pH 4.35 reaction, are only the 24.5% of the fibers in the deep area of SM muscles, being restricted to the deepest region. The 75.5% of the myofibers in the deep region are of the fast contracting types (either 48.4% 2A, SDH –positive fibers or 27.1% 2B, SDH-negative fibers, respectively). As expected the 2B muscle fibers, acidic ATPase pH 4.3-negative and SDH-negative, present the largest size, while Type 1 fibers, acidic ATPase pH 4.3-positive and SDH-positive, present the smallest size in rat SM muscle. Based on present and previous observations, comparison of change in absolute number and/or percentage of the fiber types in any experimental model of muscle atrophy/hypertrophy/plasticity/pathology /recovery in the rat SM, and possibly of all mammals, will ask for morphometry of the whole muscle cross-sections, muscle sampling by bioptic approches will provide only comparable data on the size of the different types of muscle fibers.


2006 ◽  
Vol 291 (3) ◽  
pp. 518-528 ◽  
Author(s):  
M. F. Patterson ◽  
G. M. M. Stephenson ◽  
D. G. Stephenson

Using a single, mechanically skinned fiber approach, we tested the hypothesis that denervation (0 to 50 days) of skeletal muscles that do not overlap in fiber type composition [extensor digitorum longus (EDL) and soleus (SOL) muscles of Long-Evans hooded rats] leads to development of different fiber phenotypes. Denervation (50 day) was accompanied by 1) a marked increase in the proportion of hybrid IIB/D fibers (EDL) and I/IIA fibers (SOL) from 30% to >75% in both muscles, and a corresponding decrease in the proportion of pure fibers expressing only one myosin heavy chain (MHC) isoform; 2) complex muscle- and fiber-type specific changes in sarcoplasmic reticulum Ca2+-loading level at physiological pCa ∼7.1, with EDL fibers displaying more consistent changes than SOL fibers; 3) decrease by ∼50% in specific force of all fiber types; 4) decrease in sensitivity to Ca2+, particularly for SOL fibers (by ∼40%); 5) decrease in the maximum steepness of the force-pCa curves, particularly for the hybrid I/IIA SOL fibers (by ∼35%); and 6) increased occurrence of biphasic behavior with respect to Sr2+activation in SOL fibers, indicating the presence of both slow and fast troponin C isoforms. No fiber types common to the two muscles were detected at any time points ( day 7, 21, and 50) after denervation. The results provide strong evidence that not only neural factors, but also the intrinsic properties of a muscle fiber, influence the structural and functional properties of a particular muscle cell and explain important functional changes induced by denervation at both whole muscle and single cell levels.


1985 ◽  
Vol 59 (4) ◽  
pp. 1228-1235 ◽  
Author(s):  
J. Lexell ◽  
C. Taylor ◽  
M. Sjostrom

Because of the large variability in the proportion of fiber types within a whole muscle, a single biopsy is a poor estimator of the fiber type proportion for a whole muscle. Data on the proportions of type I and II fibers, obtained from cross sections of whole human muscles (vastus lateralis) from young male individuals, have therefore been analyzed statistically in order to determine the sampling errors involved in muscle biopsy techniques. For the purpose of obtaining a good estimate of the fiber type proportion in a whole biopsy, counting all fibers is of great benefit compared with counting only half of the fiber number. The required number of biopsies to obtain a given sampling error of the mean proportion of fiber types in the whole muscle can vary by a factor of six. If less than three biopsies are taken from a muscle, there is a substantial reduction in sampling error taking biopsies with at least 600 fibers. For more than three biopsies there is a small gain in sampling greater than 150 fibers. The precision of the estimate of the mean proportion of fiber types for a group is increased with the number of biopsies per individual and number of individuals. In conclusion, for the muscle in this study, complete counting of three biopsies, each greater than 150 fibers, sampled from different depths of the muscle is recommended.


Author(s):  
Daiani de Campos ◽  
Lucas B.R. Orssatto ◽  
Gabriel S. Trajano ◽  
Walter Herzog ◽  
Heiliane de Brito Fontana

2011 ◽  
Vol 301 (4) ◽  
pp. R916-R925 ◽  
Author(s):  
Krystyna Banas ◽  
Charlene Clow ◽  
Bernard J. Jasmin ◽  
Jean-Marc Renaud

It has long been suggested that in skeletal muscle, the ATP-sensitive K+ channel (KATP) channel is important in protecting energy levels and that abolishing its activity causes fiber damage and severely impairs function. The responses to a lack of KATP channel activity vary between muscles and fibers, with the severity of the impairment being the highest in the most glycolytic muscle fibers. Furthermore, glycolytic muscle fibers are also expected to face metabolic stress more often than oxidative ones. The objective of this study was to determine whether the t-tubular KATP channel content differs between muscles and fiber types. KATP channel content was estimated using a semiquantitative immunofluorescence approach by staining cross sections from soleus, extensor digitorum longus (EDL), and flexor digitorum brevis (FDB) muscles with anti-Kir6.2 antibody. Fiber types were determined using serial cross sections stained with specific antimyosin I, IIA, IIB, and IIX antibodies. Changes in Kir6.2 content were compared with changes in CaV1.1 content, as this Ca2+ channel is responsible for triggering Ca2+ release from sarcoplasmic reticulum. The Kir6.2 content was the lowest in the oxidative soleus and the highest in the glycolytic EDL and FDB. At the individual fiber level, the Kir6.2 content within a muscle was in the order of type IIB > IIX > IIA ≥ I. Interestingly, the Kir6.2 content for a given fiber type was significantly different between soleus, EDL, and FDB, and highest in FDB. Correlations of relative fluorescence intensities from the Kir6.2 and CaV1.1 antibodies were significant for all three muscles. However, the variability in content between the three muscles or individual fibers was much greater for Kir6.2 than for CaV1.1. It is suggested that the t-tubular KATP channel content increases as the glycolytic capacity increases and as the oxidative capacity decreases and that the expression of KATP channels may be linked to how often muscles/fibers face metabolic stress.


Sign in / Sign up

Export Citation Format

Share Document