Selected contribution: Mechanisms underlying increased force generation by rat diaphragm muscle fibers during development

P. C. Geiger, M. J. Cody, R. L. Macken, M. E. Bayrd, Y. H. Fang, Gary C Sieck

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

It has been found that maximum specific force (Fmax; force per cross-sectional area) of rat diaphragm muscle doubles from birth to 84 days (adult). We hypothesize that this developmental change in Fmax reflects an increase in myosin heavy chain (MHC) content per half-sarcomere (an estimate of the number of cross bridges in parallel) and/or a greater force per cross bridge in fibers expressing fast MHC isoforms compared with slow and neonatal MHC isoforms (MHCslow and MHCneo, respectively). Single Triton 100-X-permeabilized fibers were activated at a pCa of 4.0. MHC isoform expression was determined by SDS-PAGE. MHC content per half-sarcomere was determined by densitometric analysis and comparison to a standard curve of known MHC concentrations. MHC content per half-sarcomere progressively increased during early postnatal development. When normalized for MHC content per half-sarcomere, fibers expressing MHCslow and coexpressing MHCneo produced less force than fibers expressing fast MHC isoforms. We conclude that lower force per cross bridge in fibers expressing MHCslow and MHCneo contributes to the lower Fmax seen in early postnatal development.

Original languageEnglish (US)
Pages (from-to)380-388
Number of pages9
JournalJournal of Applied Physiology
Volume90
Issue number1
StatePublished - 2001

Fingerprint

Myosin Heavy Chains
Diaphragm
Muscles
Sarcomeres
Protein Isoforms
Octoxynol
Polyacrylamide Gel Electrophoresis
Parturition

Keywords

  • Force per cross bridge
  • Maximum specific force
  • Myosin heavy chain content
  • Postnatal development
  • Single fibers

ASJC Scopus subject areas

  • Endocrinology
  • Physiology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Geiger, P. C., Cody, M. J., Macken, R. L., Bayrd, M. E., Fang, Y. H., & Sieck, G. C. (2001). Selected contribution: Mechanisms underlying increased force generation by rat diaphragm muscle fibers during development. Journal of Applied Physiology, 90(1), 380-388.

Selected contribution : Mechanisms underlying increased force generation by rat diaphragm muscle fibers during development. / Geiger, P. C.; Cody, M. J.; Macken, R. L.; Bayrd, M. E.; Fang, Y. H.; Sieck, Gary C.

In: Journal of Applied Physiology, Vol. 90, No. 1, 2001, p. 380-388.

Research output: Contribution to journalArticle

Geiger, PC, Cody, MJ, Macken, RL, Bayrd, ME, Fang, YH & Sieck, GC 2001, 'Selected contribution: Mechanisms underlying increased force generation by rat diaphragm muscle fibers during development', Journal of Applied Physiology, vol. 90, no. 1, pp. 380-388.
Geiger, P. C. ; Cody, M. J. ; Macken, R. L. ; Bayrd, M. E. ; Fang, Y. H. ; Sieck, Gary C. / Selected contribution : Mechanisms underlying increased force generation by rat diaphragm muscle fibers during development. In: Journal of Applied Physiology. 2001 ; Vol. 90, No. 1. pp. 380-388.
@article{bbe11f5663304530910eb57119435573,
title = "Selected contribution: Mechanisms underlying increased force generation by rat diaphragm muscle fibers during development",
abstract = "It has been found that maximum specific force (Fmax; force per cross-sectional area) of rat diaphragm muscle doubles from birth to 84 days (adult). We hypothesize that this developmental change in Fmax reflects an increase in myosin heavy chain (MHC) content per half-sarcomere (an estimate of the number of cross bridges in parallel) and/or a greater force per cross bridge in fibers expressing fast MHC isoforms compared with slow and neonatal MHC isoforms (MHCslow and MHCneo, respectively). Single Triton 100-X-permeabilized fibers were activated at a pCa of 4.0. MHC isoform expression was determined by SDS-PAGE. MHC content per half-sarcomere was determined by densitometric analysis and comparison to a standard curve of known MHC concentrations. MHC content per half-sarcomere progressively increased during early postnatal development. When normalized for MHC content per half-sarcomere, fibers expressing MHCslow and coexpressing MHCneo produced less force than fibers expressing fast MHC isoforms. We conclude that lower force per cross bridge in fibers expressing MHCslow and MHCneo contributes to the lower Fmax seen in early postnatal development.",
keywords = "Force per cross bridge, Maximum specific force, Myosin heavy chain content, Postnatal development, Single fibers",
author = "Geiger, {P. C.} and Cody, {M. J.} and Macken, {R. L.} and Bayrd, {M. E.} and Fang, {Y. H.} and Sieck, {Gary C}",
year = "2001",
language = "English (US)",
volume = "90",
pages = "380--388",
journal = "Journal of Applied Physiology",
issn = "8750-7587",
publisher = "American Physiological Society",
number = "1",

}

TY - JOUR

T1 - Selected contribution

T2 - Mechanisms underlying increased force generation by rat diaphragm muscle fibers during development

AU - Geiger, P. C.

AU - Cody, M. J.

AU - Macken, R. L.

AU - Bayrd, M. E.

AU - Fang, Y. H.

AU - Sieck, Gary C

PY - 2001

Y1 - 2001

N2 - It has been found that maximum specific force (Fmax; force per cross-sectional area) of rat diaphragm muscle doubles from birth to 84 days (adult). We hypothesize that this developmental change in Fmax reflects an increase in myosin heavy chain (MHC) content per half-sarcomere (an estimate of the number of cross bridges in parallel) and/or a greater force per cross bridge in fibers expressing fast MHC isoforms compared with slow and neonatal MHC isoforms (MHCslow and MHCneo, respectively). Single Triton 100-X-permeabilized fibers were activated at a pCa of 4.0. MHC isoform expression was determined by SDS-PAGE. MHC content per half-sarcomere was determined by densitometric analysis and comparison to a standard curve of known MHC concentrations. MHC content per half-sarcomere progressively increased during early postnatal development. When normalized for MHC content per half-sarcomere, fibers expressing MHCslow and coexpressing MHCneo produced less force than fibers expressing fast MHC isoforms. We conclude that lower force per cross bridge in fibers expressing MHCslow and MHCneo contributes to the lower Fmax seen in early postnatal development.

AB - It has been found that maximum specific force (Fmax; force per cross-sectional area) of rat diaphragm muscle doubles from birth to 84 days (adult). We hypothesize that this developmental change in Fmax reflects an increase in myosin heavy chain (MHC) content per half-sarcomere (an estimate of the number of cross bridges in parallel) and/or a greater force per cross bridge in fibers expressing fast MHC isoforms compared with slow and neonatal MHC isoforms (MHCslow and MHCneo, respectively). Single Triton 100-X-permeabilized fibers were activated at a pCa of 4.0. MHC isoform expression was determined by SDS-PAGE. MHC content per half-sarcomere was determined by densitometric analysis and comparison to a standard curve of known MHC concentrations. MHC content per half-sarcomere progressively increased during early postnatal development. When normalized for MHC content per half-sarcomere, fibers expressing MHCslow and coexpressing MHCneo produced less force than fibers expressing fast MHC isoforms. We conclude that lower force per cross bridge in fibers expressing MHCslow and MHCneo contributes to the lower Fmax seen in early postnatal development.

KW - Force per cross bridge

KW - Maximum specific force

KW - Myosin heavy chain content

KW - Postnatal development

KW - Single fibers

UR - http://www.scopus.com/inward/record.url?scp=0035172673&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035172673&partnerID=8YFLogxK

M3 - Article

C2 - 11133931

AN - SCOPUS:0035172673

VL - 90

SP - 380

EP - 388

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

SN - 8750-7587

IS - 1

ER -