Maximal airway response in mature and immature rabbits during tidal ventilation

Robert Tepper, X. Shen, E. Bakan, Susan Gunst

Research output: Contribution to journalArticle

50 Citations (Scopus)

Abstract

Airway closure during maximal methacholine (MCh) challenge was evaluated using alveolar capsules in eight immature and eight mature anesthetized rabbits in vivo during imposed tidal ventilation. Changes in airway opening and alveolar pressures (ΔPA) and pulmonary resistance (RE) were measured during MCh challenge at a positive end-expiratory pressure of 5 cmH2O. In immature rabbits, ΔPA remained >3 cmH2O in all animals, indicating no detectable airway closure. This contrasts to our previous study of isolated immature rabbit lungs under static conditions in which ΔPA was <0.1 cmH2O during maximal MCh challenge, findings consistent with airway closure. Airway closure also did not occur in mature animals during tidal ventilation in vivo; however, the frequency of closure in isolated lungs under static conditions was very low. With increasing MCh, end-expiratory PA increased in immature but not in mature rabbits. RL did not reach a plateau in immature rabbits during MCh, whereas a plateau was reached in mature rabbits. Immature rabbits also had greater increases in RL. These results suggest that tidal ventilation can limit bronchoconstriction in immature rabbits and prevent airway closure during maximal MCh challenge. Tidal ventilation may limit bronchoconstriction by inhibitory effects of stretch on airway smooth muscle contraction and also by causing hyperinflation and thereby increasing transpulmonary pressure.

Original languageEnglish
Pages (from-to)1190-1198
Number of pages9
JournalJournal of Applied Physiology
Volume79
Issue number4
StatePublished - 1995

Fingerprint

Ventilation
Methacholine Chloride
Rabbits
Bronchoconstriction
Lung
Pressure
Positive-Pressure Respiration
Muscle Contraction
Capsules
Smooth Muscle

Keywords

  • airway closure
  • airway reactivity
  • hyperinflation
  • maturation

ASJC Scopus subject areas

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

Cite this

Maximal airway response in mature and immature rabbits during tidal ventilation. / Tepper, Robert; Shen, X.; Bakan, E.; Gunst, Susan.

In: Journal of Applied Physiology, Vol. 79, No. 4, 1995, p. 1190-1198.

Research output: Contribution to journalArticle

@article{fb01caa0dd1d44ab93498bed18e62e25,
title = "Maximal airway response in mature and immature rabbits during tidal ventilation",
abstract = "Airway closure during maximal methacholine (MCh) challenge was evaluated using alveolar capsules in eight immature and eight mature anesthetized rabbits in vivo during imposed tidal ventilation. Changes in airway opening and alveolar pressures (ΔPA) and pulmonary resistance (RE) were measured during MCh challenge at a positive end-expiratory pressure of 5 cmH2O. In immature rabbits, ΔPA remained >3 cmH2O in all animals, indicating no detectable airway closure. This contrasts to our previous study of isolated immature rabbit lungs under static conditions in which ΔPA was <0.1 cmH2O during maximal MCh challenge, findings consistent with airway closure. Airway closure also did not occur in mature animals during tidal ventilation in vivo; however, the frequency of closure in isolated lungs under static conditions was very low. With increasing MCh, end-expiratory PA increased in immature but not in mature rabbits. RL did not reach a plateau in immature rabbits during MCh, whereas a plateau was reached in mature rabbits. Immature rabbits also had greater increases in RL. These results suggest that tidal ventilation can limit bronchoconstriction in immature rabbits and prevent airway closure during maximal MCh challenge. Tidal ventilation may limit bronchoconstriction by inhibitory effects of stretch on airway smooth muscle contraction and also by causing hyperinflation and thereby increasing transpulmonary pressure.",
keywords = "airway closure, airway reactivity, hyperinflation, maturation",
author = "Robert Tepper and X. Shen and E. Bakan and Susan Gunst",
year = "1995",
language = "English",
volume = "79",
pages = "1190--1198",
journal = "Journal of Applied Physiology",
issn = "8750-7587",
publisher = "American Physiological Society",
number = "4",

}

TY - JOUR

T1 - Maximal airway response in mature and immature rabbits during tidal ventilation

AU - Tepper, Robert

AU - Shen, X.

AU - Bakan, E.

AU - Gunst, Susan

PY - 1995

Y1 - 1995

N2 - Airway closure during maximal methacholine (MCh) challenge was evaluated using alveolar capsules in eight immature and eight mature anesthetized rabbits in vivo during imposed tidal ventilation. Changes in airway opening and alveolar pressures (ΔPA) and pulmonary resistance (RE) were measured during MCh challenge at a positive end-expiratory pressure of 5 cmH2O. In immature rabbits, ΔPA remained >3 cmH2O in all animals, indicating no detectable airway closure. This contrasts to our previous study of isolated immature rabbit lungs under static conditions in which ΔPA was <0.1 cmH2O during maximal MCh challenge, findings consistent with airway closure. Airway closure also did not occur in mature animals during tidal ventilation in vivo; however, the frequency of closure in isolated lungs under static conditions was very low. With increasing MCh, end-expiratory PA increased in immature but not in mature rabbits. RL did not reach a plateau in immature rabbits during MCh, whereas a plateau was reached in mature rabbits. Immature rabbits also had greater increases in RL. These results suggest that tidal ventilation can limit bronchoconstriction in immature rabbits and prevent airway closure during maximal MCh challenge. Tidal ventilation may limit bronchoconstriction by inhibitory effects of stretch on airway smooth muscle contraction and also by causing hyperinflation and thereby increasing transpulmonary pressure.

AB - Airway closure during maximal methacholine (MCh) challenge was evaluated using alveolar capsules in eight immature and eight mature anesthetized rabbits in vivo during imposed tidal ventilation. Changes in airway opening and alveolar pressures (ΔPA) and pulmonary resistance (RE) were measured during MCh challenge at a positive end-expiratory pressure of 5 cmH2O. In immature rabbits, ΔPA remained >3 cmH2O in all animals, indicating no detectable airway closure. This contrasts to our previous study of isolated immature rabbit lungs under static conditions in which ΔPA was <0.1 cmH2O during maximal MCh challenge, findings consistent with airway closure. Airway closure also did not occur in mature animals during tidal ventilation in vivo; however, the frequency of closure in isolated lungs under static conditions was very low. With increasing MCh, end-expiratory PA increased in immature but not in mature rabbits. RL did not reach a plateau in immature rabbits during MCh, whereas a plateau was reached in mature rabbits. Immature rabbits also had greater increases in RL. These results suggest that tidal ventilation can limit bronchoconstriction in immature rabbits and prevent airway closure during maximal MCh challenge. Tidal ventilation may limit bronchoconstriction by inhibitory effects of stretch on airway smooth muscle contraction and also by causing hyperinflation and thereby increasing transpulmonary pressure.

KW - airway closure

KW - airway reactivity

KW - hyperinflation

KW - maturation

UR - http://www.scopus.com/inward/record.url?scp=0028892029&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028892029&partnerID=8YFLogxK

M3 - Article

C2 - 8567561

AN - SCOPUS:0028892029

VL - 79

SP - 1190

EP - 1198

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

SN - 8750-7587

IS - 4

ER -