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Developmental changes in diaphragm muscle function in the preterm and postnatal lamb

Citation

Lavin, T and Song, Y and Bakker, AJ and McLean, CJ and Macdonald, WA and Noble, PB and Berry, CA and Pillow, JJ and Pinniger, GJ, Developmental changes in diaphragm muscle function in the preterm and postnatal lamb, Pediatric Pulmonology, 48, (7) pp. 640-648. ISSN 8755-6863 (2013) [Refereed Article]

Copyright Statement

Copyright 2013 Wiley Periodicals, Inc.

DOI: doi:10.1002/ppul.22762

Abstract

Rationale: The preterm diaphragm is structurally and functionally immature, potentially contributing to an increased risk of respiratory distress and failure. We investigated developmental changes in contractile function and susceptibility to fatigue of the costal diaphragm in the fetal lamb to understand factors contributing to the risk of developing diaphragm dysfunction and respiratory disorders. We hypothesized that the functional capacity of the diaphragm will vary with maturational stage as will its susceptibility to fatigue.

Methods: Lambs were studied at 75, 100, 125, 145, 154, 168, and 200 days postconceptional age (term = 147 days). Lambs were euthanized (sodium pentobarbitone, 100 mg/kg) either at delivery or immediately prior to post-mortem for postnatal lambs. Contractile function was assessed on longitudinal strips of intact muscle fibers and the remaining tissue frozen in liquid nitrogen for analysis of myosin heavy chain (MHC) mRNA expression and protein content.

Results: Fetal development of diaphragm function was characterized by a significant increase in maximum specific force, increased susceptibility to fatigue, reduced twitch contraction times, and a progressive increase in MHCI and MHCII protein content. Postnatally, there was a progressive decrease in the susceptibility to fatigue that coincided with an increase in the MHC I:II protein ratio.

Conclusion: These data indicate that the functional capacity of the diaphragm varies with maturational age and may be an important determinant of the susceptibility to preterm respiratory failure.

Item Details

Item Type:Refereed Article
Keywords:respiratory muscle, ventilation, skeletal muscle, fatigue, ontogeny
Research Division:Medical and Health Sciences
Research Group:Cardiorespiratory Medicine and Haematology
Research Field:Respiratory Diseases
Objective Division:Health
Objective Group:Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:Respiratory System and Diseases (incl. Asthma)
UTAS Author:Song, Y (Dr Yong Song)
ID Code:135712
Year Published:2013
Web of Science® Times Cited:8
Deposited By:Menzies Institute for Medical Research
Deposited On:2019-11-08
Last Modified:2019-12-06
Downloads:0

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