Myosin light chain phosphorylation and isometric twitch potentiation in intact human muscle

The effects of a single voluntary contraction of the quadriceps muscle group on phosphate incorporation into the phosphorylatable light chains (P-light chains) of fast and slow myosin isolated from the vastus lateralis muscle and potentiation of the electrically stimulated twitch tension was studied...

Full description

Saved in:
Bibliographic Details
Published in:Pflügers Archiv 1985-04, Vol.403 (4), p.348-352
Main Authors: HOUSTON, M. E, GREEN, H. J, STULL, J. T
Format: Article
Language:English
Subjects:
Adult
Biological and medical sciences
Electric Stimulation
Fundamental and applied biological sciences. Psychology
Humans
Isoenzymes - metabolism
Male
Muscle Contraction
Muscles - enzymology
Muscles - metabolism
Myosin-Light-Chain Kinase
Myosins - metabolism
Phosphates - metabolism
Phosphorylation
Protein Kinases - metabolism
Rest
Striated muscle. Tendons
Vertebrates: osteoarticular system, musculoskeletal system
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The effects of a single voluntary contraction of the quadriceps muscle group on phosphate incorporation into the phosphorylatable light chains (P-light chains) of fast and slow myosin isolated from the vastus lateralis muscle and potentiation of the electrically stimulated twitch tension was studied in intact human muscle. Twitch potentiation was maximal 20 s after the voluntary contraction. Thereafter, twitch potentiation declined, but was still significantly higher than pre-contraction values 2 min after the voluntary contraction. Phosphate incorporation into the P-light chain of fast myosin followed a similar time course to twitch potentiation, but no phosphate was incorporated into slow myosin P-light chains. These observations suggest that myosin light chain kinase activity is mainly associated with fast-twitch muscle fibers and, in agreement with previous studies, suggests that twitch potentiation associated with P-light chain phosphorylation is confined to the fast-twitch fibers of human muscle.
ISSN:0031-6768
1432-2013
DOI:10.1007/bf00589245