No Systematic Difference in AMP Deaminase Levels between Type I and Type II Fibres in Human Skeletal Muscle

1994 ◽  
Vol 87 (s1) ◽  
pp. 124-124
Author(s):  
B Norman ◽  
E Jansson ◽  
Karolinska Institute
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Systematic Difference ◽  
Type I ◽  
Type Ii ◽  
Amp Deaminase

Relaxation Rate of Type I and Type II Fibres in Human Skeletal Muscle

1978 ◽  
Vol 54 (2) ◽  
pp. 31P-32P ◽  
Author(s):  
C. M. Wiles ◽  
D. A. Jones ◽  
A. Young ◽  
R. H. T. Edwards
Keyword(s):  
Skeletal Muscle ◽  
Relaxation Rate ◽  
Human Skeletal Muscle ◽  
Type I ◽  
Type Ii

Muscle fiber type-specific response of Hsp70 expression in human quadriceps following acute isometric exercise

2007 ◽  
Vol 103 (6) ◽  
pp. 2105-2111 ◽  
Author(s):  
A. R. Tupling ◽  
E. Bombardier ◽  
R. D. Stewart ◽  
C. Vigna ◽  
A. E. Aqui
Keyword(s):  
Skeletal Muscle ◽  
Time Course ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
Hsp70 Expression ◽  
Type I ◽  
Fiber Types ◽  
Type Ii ◽  
Exercise Induced ◽  
Type I Fibers

To investigate the time course of fiber type-specific heat shock protein 70 (Hsp70) expression in human skeletal muscle after acute exercise, 10 untrained male volunteers performed single-legged isometric knee extensor exercise at 60% of their maximal voluntary contraction (MVC) with a 50% duty cycle (5-s contraction and 5-s relaxation) for 30 min. Muscle biopsies were collected from the vastus lateralis before (Pre) exercise in the rested control leg (C) and immediately after exercise (Post) in the exercised leg (E) only and on recovery days 1 (R1), 2 (R2), 3 (R3), and 6 (R6) from both legs. As demonstrated by Western blot analysis, whole muscle Hsp70 content was unchanged ( P > 0.05) immediately after exercise (Pre vs. Post), was increased ( P < 0.05) by ∼43% at R1, and remained elevated throughout the entire recovery period in E only. Hsp70 expression was also assessed in individual muscle fiber types I, IIA, and IIAX/IIX by immunohistochemistry. There were no fiber type differences ( P > 0.05) in basal Hsp70 expression. Immediately after exercise, Hsp70 expression was increased ( P < 0.05) in type I fibers by ∼87% but was unchanged ( P > 0.05) in type II fibers (Pre vs. Post). At R1 and throughout recovery, Hsp70 content in E was increased above basal levels ( P < 0.05) in all fiber types, but Hsp70 expression was always highest ( P < 0.05) in type I fibers. Hsp70 content in C was not different from Pre at any time throughout recovery. Glycogen depletion was observed at Post in all type II, but not type I, fibers, suggesting that the fiber type differences in exercise-induced Hsp70 expression were not related to glycogen availability. These results demonstrate that the time course of exercise-induced Hsp70 expression in human skeletal muscle is fiber type specific.

Low sulphur content in atrophied human skeletal muscle: an electron probe X-ray microanalytical study

1978 ◽  
Vol 36 (2) ◽  
pp. 634-635
Author(s):  
R. Wróblewski ◽  
W. Gremski ◽  
G. M. Roomans ◽  
R. Nordemar ◽  
L. Edström
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Control Group ◽  
Muscle Fibres ◽  
Type I ◽  
Tissue Preparation ◽  
Type Ii ◽  
Slow Twitch ◽  
Fibre Typing ◽  
Fast Twitch

Many diseases of the human skeletal muscle involve an atrophy of the muscle fibres. In some cases mainly one of the fibre types is affected. The fibre typing system used in this study is that of Padykula and Herman, 1955 and distinguishes between type I fibres which presumably correspond to the slow-twitch fibres and type II fibres which are the fast-twitch fibres. The type II fibres can be divided into type II A, II B and II C fibres. Recent advances in instrumentation and tissue preparation have permitted an investigation of the elemental composition of individual muscle fibres of known fibre type with the aim of comparing healthy and atrophied muscle fibres.In this study we have examined ten patients suffering from rheumatoid arthritis, two patients suffering from Parkinson's disease and two patients with upper motor lesions. As a control group we have examined muscles from eight healthy controls of the same age.

Increase in S6K1 phosphorylation in human skeletal muscle following resistance exercise occurs mainly in type II muscle fibers

2006 ◽  
Vol 290 (6) ◽  
pp. E1245-E1252 ◽  
Author(s):  
René Koopman ◽  
Antoine H. G. Zorenc ◽  
Rudy J. J. Gransier ◽  
David Cameron-Smith ◽  
Luc J. C. van Loon
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
Muscle Fibers ◽  
Initiation Factor ◽  
Exercise Session ◽  
Type I ◽  
Type Ii ◽  
Postexercise Recovery

To investigate the in vivo effects of resistance exercise on translational control in human skeletal muscle, we determined the phosphorylation of AMP-activated kinase (AMPK), eukaryotic initiation factor 4E-binding protein (4E-BP1), p70/p85-S6 protein kinase (S6K1), and ribosomal S6 protein (S6). Furthermore, we investigated whether changes in the phosphorylation of S6K1 are muscle fiber type specific. Eight male subjects performed a single high-intensity resistance exercise session. Muscle biopsies were collected before and immediately after exercise and after 30 and 120 min of postexercise recovery. The phosphorylation statuses of AMPK, 4E-BP1, S6K1, and S6 were determined by Western blotting with phospho-specific and pan antibodies. To determine fiber type-specific changes in the phosphorylation status of S6K1, immunofluorescence microscopy was applied. AMPK phosphorylation was increased approximately threefold immediately after resistance exercise, whereas 4E-BP1 phosphorylation was reduced to 27 ± 6% of preexercise values. Phosphorylation of S6K1 at Thr421/Ser424 was increased 2- to 2.5-fold during recovery but did not induce a significant change in S6 phosphorylation. Phosphorylation of S6K1 was more pronounced in the type II vs. type I muscle fibers. Before exercise, phosphorylated S6K1 was predominantly located in the nuclei. After 2 h of postexercise recovery, phospho-S6K1 was primarily located in the cytosol of type II muscle fibers. We conclude that resistance exercise effectively increases the phosphorylation of S6K1 on Thr421/Ser424, which is not associated with a substantial increase in S6 phosphorylation in a fasted state.

9: 45 a.m.: ULTRASTRUCTURE OF TYPE I AND TYPE II FIBERS IK HUMAN SKELETAL MUSCLE

1981 ◽  
Vol 13 (2) ◽  
pp. 95 ◽  
Author(s):  
S. E. Alway ◽  
J. D. MacDougall ◽  
D. G. Sale ◽  
G. Elder ◽  
J. R. Sutton
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Type I ◽  
Type Ii ◽  
Type Ii Fibers

Genetic and other determinants of AMP deaminase activity in healthy adult skeletal muscle

1998 ◽  
Vol 85 (4) ◽  
pp. 1273-1278 ◽  
Author(s):  
Barbara Norman ◽  
Donna K. Mahnke-Zizelman ◽  
Amy Vallis ◽  
Richard L. Sabina
Keyword(s):  
Skeletal Muscle ◽  
Enzyme Activity ◽  
Mutant Allele ◽  
Fiber Type ◽  
Type I ◽  
Training Status ◽  
Amp Deaminase ◽  
Normal Allele ◽  
Relative Percentage ◽  
Type I Fibers

AMPD1 genotype, relative fiber type composition, training status, and gender were evaluated as contributing factors to the reported variation in AMP deaminase enzyme activity in healthy skeletal muscle. Multifactorial correlative analyses demonstrate that AMPD1 genotype has the greatest effect on enzyme activity. An AMPD1 mutant allele frequency of 13.7 and a 1.7% incidence of enzyme deficiency was found across 175 healthy subjects. Homozygotes for the AMPD1 normal allele have high enzyme activities, and heterozygotes display intermediate activities. When examined according to genotype, other factors were found to affect variability as follows: AMP deaminase activity in homozygotes for the normal allele exhibits a negative correlation with the relative percentage of type I fibers and training status. Conversely, residual AMP deaminase activity in homozygotes for the mutant allele displays a positive correlation with the relative percentage of type I fibers. Opposing correlations in different homozygous AMPD1 genotypes are likely due to relative fiber-type differences in the expression of AMPD1 and AMPD3 isoforms. Gender also contributes to variation in total skeletal muscle AMP deaminase activity, with normal homozygous and heterozygous women showing only 85–88% of the levels observed in genotype-matched men.

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