Mechanisms for the mechanical response of airway smooth muscle to length oscillation

X. Shen, M. F. Wu, Robert Tepper, Susan Gunst

Research output: Contribution to journalArticle

139 Citations (Scopus)

Abstract

Airway smooth muscle tone in vitro is profoundly affected by oscillations in muscle length, suggesting that the effects of lung volume changes on airway tone result from direct effects of stretch on the airway smooth muscle. We analyzed the effect of length oscillation on active force and length-force hysteresis in canine tracheal smooth muscle at different oscillation rates and amplitudes during contraction with acetylcholine. During the shortening phase of the length oscillation cycle, the active force generated by the smooth muscle decreased markedly below the isometric force but returned to isometric force as the muscle was lengthened. Results indicate that at rates comparable to those during tidal breathing, active shortening and yielding of contractile elements contributes to the modulation of force during length oscillation; however, the depression of force during shortening cannot be accounted for by cross-bridge properties, shortening- induced cross-bridge deactivation, or active relaxation. We conclude that the depression of contractility may be a function of the plasticity of the cellular organization of contractile filaments, which enables contractile element length to be reset in relation to smooth muscle cell length as a result of smooth muscle stretch.

Original languageEnglish
Pages (from-to)731-738
Number of pages8
JournalJournal of Applied Physiology
Volume83
Issue number3
StatePublished - Sep 1997

Fingerprint

Smooth Muscle
Muscles
Acetylcholine
Smooth Muscle Myocytes
Canidae
Respiration
Lung

Keywords

  • Airway reactivity
  • Contractile mechanisms
  • Tidal breathing
  • Tracheal smooth muscle

ASJC Scopus subject areas

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

Cite this

Mechanisms for the mechanical response of airway smooth muscle to length oscillation. / Shen, X.; Wu, M. F.; Tepper, Robert; Gunst, Susan.

In: Journal of Applied Physiology, Vol. 83, No. 3, 09.1997, p. 731-738.

Research output: Contribution to journalArticle

@article{b27af86655ef4394873df06f2b7944a8,
title = "Mechanisms for the mechanical response of airway smooth muscle to length oscillation",
abstract = "Airway smooth muscle tone in vitro is profoundly affected by oscillations in muscle length, suggesting that the effects of lung volume changes on airway tone result from direct effects of stretch on the airway smooth muscle. We analyzed the effect of length oscillation on active force and length-force hysteresis in canine tracheal smooth muscle at different oscillation rates and amplitudes during contraction with acetylcholine. During the shortening phase of the length oscillation cycle, the active force generated by the smooth muscle decreased markedly below the isometric force but returned to isometric force as the muscle was lengthened. Results indicate that at rates comparable to those during tidal breathing, active shortening and yielding of contractile elements contributes to the modulation of force during length oscillation; however, the depression of force during shortening cannot be accounted for by cross-bridge properties, shortening- induced cross-bridge deactivation, or active relaxation. We conclude that the depression of contractility may be a function of the plasticity of the cellular organization of contractile filaments, which enables contractile element length to be reset in relation to smooth muscle cell length as a result of smooth muscle stretch.",
keywords = "Airway reactivity, Contractile mechanisms, Tidal breathing, Tracheal smooth muscle",
author = "X. Shen and Wu, {M. F.} and Robert Tepper and Susan Gunst",
year = "1997",
month = "9",
language = "English",
volume = "83",
pages = "731--738",
journal = "Journal of Applied Physiology",
issn = "8750-7587",
publisher = "American Physiological Society",
number = "3",

}

TY - JOUR

T1 - Mechanisms for the mechanical response of airway smooth muscle to length oscillation

AU - Shen, X.

AU - Wu, M. F.

AU - Tepper, Robert

AU - Gunst, Susan

PY - 1997/9

Y1 - 1997/9

N2 - Airway smooth muscle tone in vitro is profoundly affected by oscillations in muscle length, suggesting that the effects of lung volume changes on airway tone result from direct effects of stretch on the airway smooth muscle. We analyzed the effect of length oscillation on active force and length-force hysteresis in canine tracheal smooth muscle at different oscillation rates and amplitudes during contraction with acetylcholine. During the shortening phase of the length oscillation cycle, the active force generated by the smooth muscle decreased markedly below the isometric force but returned to isometric force as the muscle was lengthened. Results indicate that at rates comparable to those during tidal breathing, active shortening and yielding of contractile elements contributes to the modulation of force during length oscillation; however, the depression of force during shortening cannot be accounted for by cross-bridge properties, shortening- induced cross-bridge deactivation, or active relaxation. We conclude that the depression of contractility may be a function of the plasticity of the cellular organization of contractile filaments, which enables contractile element length to be reset in relation to smooth muscle cell length as a result of smooth muscle stretch.

AB - Airway smooth muscle tone in vitro is profoundly affected by oscillations in muscle length, suggesting that the effects of lung volume changes on airway tone result from direct effects of stretch on the airway smooth muscle. We analyzed the effect of length oscillation on active force and length-force hysteresis in canine tracheal smooth muscle at different oscillation rates and amplitudes during contraction with acetylcholine. During the shortening phase of the length oscillation cycle, the active force generated by the smooth muscle decreased markedly below the isometric force but returned to isometric force as the muscle was lengthened. Results indicate that at rates comparable to those during tidal breathing, active shortening and yielding of contractile elements contributes to the modulation of force during length oscillation; however, the depression of force during shortening cannot be accounted for by cross-bridge properties, shortening- induced cross-bridge deactivation, or active relaxation. We conclude that the depression of contractility may be a function of the plasticity of the cellular organization of contractile filaments, which enables contractile element length to be reset in relation to smooth muscle cell length as a result of smooth muscle stretch.

KW - Airway reactivity

KW - Contractile mechanisms

KW - Tidal breathing

KW - Tracheal smooth muscle

UR - http://www.scopus.com/inward/record.url?scp=0030866194&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030866194&partnerID=8YFLogxK

M3 - Article

C2 - 9292457

AN - SCOPUS:0030866194

VL - 83

SP - 731

EP - 738

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

SN - 8750-7587

IS - 3

ER -