?B-crystallin in oxidative muscle fibers and its accumulation in ragged-red fibers: a comparative immunohistochemical and histochemical study in human skeletal muscle

1993 ◽  
Vol 85 (5) ◽  
Author(s):  
Toru Iwaki ◽  
Akiko Iwaki ◽  
JamesE. Goldman
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Histochemical Study ◽  
Muscle Fibers ◽  
Ragged Red Fibers

scholarly journals THE DISTRIBUTION OF LACTATE DEHYDROGENASE ISOZYMES IN HUMAN SKELETAL MUSCLE FIBERS

1964 ◽  
Vol 12 (8) ◽  
pp. 608-614 ◽  
Author(s):  
M. VAN WIJHE ◽  
M. C. BLANCHAER ◽  
S. ST. GEORGE-STUBBS
Keyword(s):  
Skeletal Muscle ◽  
Lactate Dehydrogenase ◽  
Human Skeletal Muscle ◽  
Muscle Fibers ◽  
Isozyme Pattern ◽  
Electrophoretic Separation ◽  
Lactate Dehydrogenase Isozymes ◽  
Dehydrogenase Isozyme ◽  
Lactate Dehydrogenase Isozyme ◽  
Normal Human

A study of the distribution of lactate dehydrogenase isozymes in single fibers from normal human skeletal muscle is presented. The fibers were classified into red, intermediate and white types on histochemical grounds and their lactate dehydrogenase isozyme content assessed by electrophoretic separation in veronal buffered agar. The results generally agreed with previous homogenate studies on animal skeletal muscle, in that the white fibers contained almost exclusively isozymes IV and V, whereas red fibers were rich in isozymes I, II and III, but IV and V also appeared indigenous to these fibers. The intermediate fibers had an isozyme pattern combining the features of red and white fibers. The metabolic implications of these findings are discussed.

RPS6 phosphorylation occurs to a greater extent in the periphery of human skeletal muscle fibers, near focal adhesions, after anabolic stimuli

2021 ◽  
Author(s):  
Nathan Hodson ◽  
Michael Mazzulla ◽  
Maksym N. H. Holowaty ◽  
Dinesh Kumbhare ◽  
Daniel R. Moore
Keyword(s):  
Skeletal Muscle ◽  
Focal Adhesion ◽  
Human Skeletal Muscle ◽  
Muscle Fibers ◽  
Focal Adhesions ◽  
Immunofluorescent Staining ◽  
Whole Body ◽  
Vastus Lateralis Muscle ◽  
Cell Periphery ◽  
Rps6 Phosphorylation

Following anabolic stimuli (mechanical loading and/or amino acid provision) the mechanistic target of rapamycin complex 1 (mTORC1), a master regulator of protein synthesis, translocates toward the cell periphery. However, it is unknown if mTORC1-mediated phosphorylation events occur in these peripheral regions or prior to translocation (i.e. in central regions). We therefore aimed to determine the cellular location of a mTORC1-mediated phosphorylation event, RPS6Ser240/244, in human skeletal muscle following anabolic stimuli. Fourteen young, healthy males either ingested a protein-carbohydrate beverage (0.25g/kg protein, 0.75g/kg carbohydrate) alone (n=7;23±5yrs;76.8±3.6kg;13.6±3.8%BF, FED) or following a whole-body resistance exercise bout (n=7;22±2yrs;78.1±3.6kg;12.2±4.9%BF, EXFED). Vastus lateralis muscle biopsies were obtained at rest (PRE) and 120 and 300min following anabolic stimuli. RPS6Ser240/244 phosphorylation measured by immunofluorescent staining or immunoblot was positively correlated (r=0.76, p<0.001). Peripheral staining intensity of p-RPS6Ser240/244 increased above PRE in both FED and EXFED at 120min (~54% and ~138% respectively, p<0.05) but was greater in EXFED at both post-stimuli time points (p<0.05). The peripheral-central ratio of p-RPS6240/244 staining displayed a similar pattern, even when corrected for total RPS6 distribution, suggesting RPS6 phosphorylation occurs to a greater extent in the periphery of fibers. Moreover, p-RPS6Ser240/244 intensity within paxillin-positive regions, a marker of focal adhesion complexes, was elevated at 120min irrespective of stimulus (p=0.006) before returning to PRE at 300min. These data confirm that RPS6Ser240/244 phosphorylation occurs in the region of human muscle fibers to which mTOR translocates following anabolic stimuli and identifies focal adhesion complexes as a potential site of mTORC1 regulation in vivo.

Glycogen depletion patterns in human skeletal muscle fibers during prolonged work

1973 ◽  
Vol 344 (1) ◽  
pp. 1-12 ◽  
Author(s):  
P. D. Gollnick ◽  
R. B. Armstrong ◽  
C. W. Saubert ◽  
W. L. Sembrowich ◽  
R. E. Shepherd ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Muscle Fibers ◽  
Glycogen Depletion ◽  
Skeletal Muscle Fibers

scholarly journals A three-dimensional culture model of innervated human skeletal muscle enables studies of the adult neuromuscular junction and disease modeling

2018 ◽  
Author(s):  
Mohsen Afshar Bakooshli ◽  
Ethan S Lippmann ◽  
Ben Mulcahy ◽  
Nisha R Iyer ◽  
Christine T Nguyen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Neuromuscular Junction ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Human Skeletal Muscle ◽  
Disease Modeling ◽  
De Novo ◽  
Muscle Fibers ◽  
Three Dimensional ◽  
Adult Human

SummaryTwo-dimensional (2D) human skeletal muscle fiber cultures are ill equipped to support the contractile properties of maturing muscle fibers. This limits their application to the study of adult human neuromuscular junction (NMJ) development, a process requiring maturation of muscle fibers in the presence of motor neuron endplates. Here we describe a three-dimensional (3D) co-culture method whereby human muscle progenitors mixed with human pluripotent stem cell-derived motor neurons self-organize to form functional NMJ connections within two weeks. Functional connectivity between motor neuron endplates and muscle fibers is confirmed with calcium transient imaging and electrophysiological recordings. Notably, we only observed epsilon acetylcholine receptor subunit protein upregulation and activity in 3D co-culture. This demonstrates that the 3D co-culture system supports a developmental shift from the embryonic to adult form of the receptor that does not occur in 2D co-culture. Further, 3D co-culture treatments with myasthenia gravis patient sera shows the ease of studying human disease with the system. This work delivers a simple, reproducible, and adaptable method to model and evaluate adult human NMJ de novo development and disease in culture.

Skeletal muscle beta-adrenoceptor distribution and responses to isoproterenol in hyperthyroidism

1992 ◽  
Vol 262 (4) ◽  
pp. E504-E510 ◽  
Author(s):  
W. H. Martin ◽  
E. Korte ◽  
T. K. Tolley ◽  
J. E. Saffitz
Keyword(s):  
Skeletal Muscle ◽  
Adrenergic Receptor ◽  
Human Skeletal Muscle ◽  
Muscle Fibers ◽  
Type I ◽  
Receptor Density ◽  
Adrenergic Stimulation ◽  
Beta Adrenergic Receptor ◽  
Beta Adrenergic ◽  
Isoproterenol Infusion

To determine whether hyperthyroidism selectively increases beta-adrenergic receptor density in vessels or fibers of human skeletal muscle, we characterized beta-receptor distribution autoradiographically in muscle biopsies of 18 subjects aged 26 +/- 1 yr before and after daily administration of 100 micrograms 3,5,3'-triiodothyronine (T3) for 2 wk. To establish whether vascular and metabolic responses to beta-adrenergic stimulation are concomitantly altered, we quantified calf blood flow and plasma concentrations of glucose, lactate, glycerol, free fatty acids (FFA), insulin, and C-peptide during graded-dose isoproterenol infusion in eight of these individuals. Differences in beta-adrenergic receptor density among muscle fiber types and vascular components were highly significant (type I greater than type IIa greater than type IIb muscle fibers, P less than 0.001; and type I muscle fibers greater than resistance arterioles, P less than 0.05). Hyperthyroidism increased beta-adrenergic receptor density in all types of muscle fibers (+31-50%; P less than 0.01) but not in resistance arterioles. There was no change in calf blood flow or plasma glucose, glycerol, FFA, insulin, or C-peptide responses to isoproterenol. A rise in lactate during stages 3 and 4 of isoproterenol infusion (P less than 0.01) was observed before but not after T3 administration. Thus hyperthyroidism increases beta-adrenergic receptor density in fibers but not vessels of human skeletal muscle without increasing either metabolic or vascular responses to selective beta-adrenergic stimulation.

Induction of GLUT-1 protein in adult human skeletal muscle fibers

2000 ◽  
Vol 279 (5) ◽  
pp. E1191-E1195 ◽  
Author(s):  
M. Gaster ◽  
J. Franch ◽  
P. Staehr ◽  
H. Beck-Nielsen ◽  
T. Smith ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Contractile Activity ◽  
Muscle Fibers ◽  
Insulin Dependent Diabetes Mellitus ◽  
Human Muscle ◽  
Dependent Diabetes Mellitus ◽  
Glut 1 ◽  
Adult Human ◽  
Skeletal Muscle Fibers

Prompted by our recent observations that GLUT-1 is expressed in fetal muscles, but not in adult muscle fibers, we decided to investigate whether GLUT-1 expression could be reactivated. We studied different stimuli concerning their ability to induce GLUT-1 expression in mature human skeletal muscle fibers. Metabolic stress (obesity, non-insulin-dependent diabetes mellitus), contractile activity (training), and conditions of de- and reinnervation (amyotrophic lateral sclerosis) could not induce GLUT-1 expression in human muscle fibers. However, regenerating muscle fibers in polymyositis expressed GLUT-1. In contrast to GLUT-1, GLUT-4 was expressed in all investigated muscle fibers. Although the significance of GLUT-1 in adult human muscle fibers appears limited, GLUT-1 may be of importance for the glucose supplies in immature and regenerating muscle.

Expression of Midkine in Regenerating Skeletal Muscle Fibers and Cultured Myoblasts of Human Skeletal Muscle

2002 ◽  
Vol 47 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Jing Hu ◽  
Itsuro Higuchi ◽  
Yoshihiro Yoshida ◽  
Tadafumi Shiraishi ◽  
Mitsuhiro Osame
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Muscle Fibers ◽  
Skeletal Muscle Fibers
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