Projects per year
Abstract
Fetal airway smooth muscle (ASM) exhibits phasic contractile behavior, which transitions to a more sustained “tonic” contraction after birth. The timing and underlying mechanisms of ASM transition from a phasic to a tonic contractile phenotype are yet to be established. We characterized phasic ASM contraction in preterm (128 day gestation), term (∼150 day gestation), 1–4 month, 1 yr, and adult sheep (5yr). Spontaneous phasic activity was measured in bronchial segments as amplitude, frequency, and intensity. The mechanism of phasic ASM contraction was investigated further with a computational model of ASM force development and lumen narrowing. The computational model comprised a two-dimensional cylindrical geometry of a network of contractile units and the activation of neighboring cells was dependent on the strength of coupling between cells. As expected, phasic contractions were most prominent in fetal airways and decreased with advancing age, to a level similar to the level in the 1–4 month lambs. Computational predictions demonstrated phasic contraction through the generation of a wave of activation events, the magnitude of which is determined by the number of active cells and the strength of cell–cell interactions. Decreases in phasic contraction with advancing age were simulated by reducing cell–cell coupling. Results show that phasic activity is suppressed rapidly after birth, then sustained at a lower intensity from the preweaning phase until adulthood in an ovine developmental model. Cell–cell coupling is proposed as a key determinant of phasic ASM contraction and if reduced could explain the observed maturational changes.
Original language | English |
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Pages (from-to) | 011003-1 - 011003-9 |
Number of pages | 9 |
Journal | ASME Journal of Engineering and Science in Medical Diagnostics and Therapy |
Volume | 2 |
Issue number | 1 |
DOIs | |
Publication status | Published - Feb 2019 |
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Dive into the research topics of 'Transition from phasic to tonic contractility in airway smooth muscle after birth: An experimental and computational modeling study'. Together they form a unique fingerprint.Projects
- 5 Finished
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Ontogeny of the airway smooth muscle layer
Noble, P. (Investigator 01), Pillow, J. (Investigator 02), James, A. (Investigator 03) & Elliot, J. (Investigator 04)
NHMRC National Health and Medical Research Council
1/01/15 → 31/12/19
Project: Research
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Understanding & Improving Treatment of Premature Infants to Improve Long Term Outcomes
Pillow, J. (Investigator 01)
NHMRC National Health and Medical Research Council
1/01/15 → 31/12/19
Project: Research
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Role of airway smooth muscle on the development of asthma
Wang, K. (Investigator 01)
NHMRC National Health and Medical Research Council
1/01/15 → 31/12/19
Project: Research