PMID- 10658030
OWN - NLM
STAT- MEDLINE
DCOM- 20000303
LR  - 20171213
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 88
IP  - 2
DP  - 2000 Feb
TI  - Progressive resistance training reduces myosin heavy chain coexpression in single 
      muscle fibers from older men.
PG  - 627-33
AB  - The purpose of this study was to examine myosin heavy chain (MHC) and myosin 
      light chain (MLC) isoforms following 12 wk of progressive resistance training 
      (PRT). A needle biopsy was taken from the vastus lateralis to determine 
      fiber-type expression [ATPase (pH 4.54) and MHC/MLC] in seven healthy men (age = 
      74.0 +/- 1.8 yr). Subjects were also tested for 1-repetition maximum (1-RM), pre- 
      and posttraining. The progressive knee extensor protocol consisted of three sets 
      at 80% of 1-RM 3 days/wk for 12 wk. Freeze-dried, single muscle fibers were 
      dissected for MHC and MLC analysis and then subjected to SDS-PAGE and silver 
      staining, pre- and posttraining. MHC expression increased in the I (10.4%; P < 
      0.05) and decreased in I/IIa (9.0%; P < 0.05), I/IIa/x (0.9%; P < 0.05), and 
      IIa/x (8.9%; P < 0.05) isoforms, with no change in the IIa and IIx isoforms, pre- 
      vs. posttraining (total fibers = 3,059). The MLC(3f)-to-MLC(2) ratio did not 
      change with the PRT in either the MHC I or MHC IIa isoforms (total fibers = 902), 
      pre- to posttraining. ATPase fiber distribution did not significantly differ 
      following training (I: 50. 4 +/- 6.7 vs. 51.9 +/- 7.9, IIa: 36.8 +/- 5.3 vs. 41.1 
      +/- 7.0, IIb: 12.8 +/- 5.6 vs. 7.0 +/- 4.0%; pre- vs. posttraining, 
      respectively). 1-RM increased (51.9%; P < 0.05) from pre- to posttraining. The 
      PRT provide a stimulus for alterations in MHC isoforms, which demonstrated a 
      decrease in all hybrid isoforms and an increase in MHC I expression (not found in 
      the ATPase results), unlike the MLC ratio (3:2), which was not altered with 
      training.
FAU - Williamson, D L
AU  - Williamson DL
AD  - Human Performance Laboratory, Ball State University, Muncie, Indiana 47306, USA.
FAU - Godard, M P
AU  - Godard MP
FAU - Porter, D A
AU  - Porter DA
FAU - Costill, D L
AU  - Costill DL
FAU - Trappe, S W
AU  - Trappe SW
LA  - eng
GR  - AG-154876/AG/NIA NIH HHS/United States
PT  - Clinical Trial
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
RN  - 0 (Myosin Light Chains)
RN  - 0 (Protein Isoforms)
RN  - EC 3.6.1.- (Adenosine Triphosphatases)
RN  - EC 3.6.4.1 (Myosin Heavy Chains)
SB  - IM
MH  - Adenosine Triphosphatases/metabolism
MH  - Aged/*physiology
MH  - Electrophoresis, Polyacrylamide Gel
MH  - Humans
MH  - Male
MH  - Muscle Fibers, Skeletal/enzymology/*metabolism
MH  - Myosin Heavy Chains/*biosynthesis
MH  - Myosin Light Chains/biosynthesis
MH  - Physical Exertion/*physiology
MH  - Protein Isoforms/biosynthesis
EDAT- 2000/02/05 09:00
MHDA- 2000/03/11 09:00
CRDT- 2000/02/05 09:00
PHST- 2000/02/05 09:00 [pubmed]
PHST- 2000/03/11 09:00 [medline]
PHST- 2000/02/05 09:00 [entrez]
AID - 10.1152/jappl.2000.88.2.627 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 2000 Feb;88(2):627-33. doi: 10.1152/jappl.2000.88.2.627.