Abstract
Maximal airway narrowing during bronchoconstriction is greater in immature than in mature rabbits. At a given transpulmonary pressure (PL), the lung parenchyma surrounding the airway resists local deformation and provides a load that opposes airway smooth muscle shortening. We hypothesized that the force required to produce lung parenchymal deformation, quantified by the shear modulus, is lower in immature rabbit lungs. The shear modulus and the bulk modulus were measured in isolated mature (n = 8; 6 mo) and immature (n = 9; 3 wk) rabbit lungs at PL of 2, 4, 6, 8, and 10 cmH2O. The bulk modulus increased with increasing PL for mature and immature lungs; however, there was no significant difference between the groups. The shear modulus was lower for the immature than the mature lungs (P < 0.025), progressively increasing with increasing PL (P < 0.001) for both groups, and there was no difference between the slopes for shear modulus vs. PL for the mature and the immature lungs. The mean value of the shear modulus for mature and immature rabbit lungs at PL = 6 cmH2O was 4.5 vs. 3.8 cmH2O. We conclude that the shear modulus is less in immature than mature rabbit lungs. This small maturational difference in the shear modulus probably does not account for the greater airway narrowing in the immature lung, unless its effect is coupled with a relatively thicker and more compliant airway wall in the immature animal.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 711-714 |
| Number of pages | 4 |
| Journal | Journal of Applied Physiology |
| Volume | 87 |
| Issue number | 2 |
| State | Published - Jan 1 1999 |
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Keywords
- Lung parenchyma
- Maturation
- Rabbits
- Shear modulus
ASJC Scopus subject areas
- Physiology
- Endocrinology
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation
Cite this
Comparison of the shear modulus of mature and immature rabbit lungs. / Tepper, Robert S.; Wiggs, Barry; Gunst, Susan J.; Paré, Peter D.
In: Journal of Applied Physiology, Vol. 87, No. 2, 01.01.1999, p. 711-714.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Comparison of the shear modulus of mature and immature rabbit lungs
AU - Tepper, Robert S.
AU - Wiggs, Barry
AU - Gunst, Susan J.
AU - Paré, Peter D.
PY - 1999/1/1
Y1 - 1999/1/1
N2 - Maximal airway narrowing during bronchoconstriction is greater in immature than in mature rabbits. At a given transpulmonary pressure (PL), the lung parenchyma surrounding the airway resists local deformation and provides a load that opposes airway smooth muscle shortening. We hypothesized that the force required to produce lung parenchymal deformation, quantified by the shear modulus, is lower in immature rabbit lungs. The shear modulus and the bulk modulus were measured in isolated mature (n = 8; 6 mo) and immature (n = 9; 3 wk) rabbit lungs at PL of 2, 4, 6, 8, and 10 cmH2O. The bulk modulus increased with increasing PL for mature and immature lungs; however, there was no significant difference between the groups. The shear modulus was lower for the immature than the mature lungs (P < 0.025), progressively increasing with increasing PL (P < 0.001) for both groups, and there was no difference between the slopes for shear modulus vs. PL for the mature and the immature lungs. The mean value of the shear modulus for mature and immature rabbit lungs at PL = 6 cmH2O was 4.5 vs. 3.8 cmH2O. We conclude that the shear modulus is less in immature than mature rabbit lungs. This small maturational difference in the shear modulus probably does not account for the greater airway narrowing in the immature lung, unless its effect is coupled with a relatively thicker and more compliant airway wall in the immature animal.
AB - Maximal airway narrowing during bronchoconstriction is greater in immature than in mature rabbits. At a given transpulmonary pressure (PL), the lung parenchyma surrounding the airway resists local deformation and provides a load that opposes airway smooth muscle shortening. We hypothesized that the force required to produce lung parenchymal deformation, quantified by the shear modulus, is lower in immature rabbit lungs. The shear modulus and the bulk modulus were measured in isolated mature (n = 8; 6 mo) and immature (n = 9; 3 wk) rabbit lungs at PL of 2, 4, 6, 8, and 10 cmH2O. The bulk modulus increased with increasing PL for mature and immature lungs; however, there was no significant difference between the groups. The shear modulus was lower for the immature than the mature lungs (P < 0.025), progressively increasing with increasing PL (P < 0.001) for both groups, and there was no difference between the slopes for shear modulus vs. PL for the mature and the immature lungs. The mean value of the shear modulus for mature and immature rabbit lungs at PL = 6 cmH2O was 4.5 vs. 3.8 cmH2O. We conclude that the shear modulus is less in immature than mature rabbit lungs. This small maturational difference in the shear modulus probably does not account for the greater airway narrowing in the immature lung, unless its effect is coupled with a relatively thicker and more compliant airway wall in the immature animal.
KW - Lung parenchyma
KW - Maturation
KW - Rabbits
KW - Shear modulus
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UR - http://www.scopus.com/inward/citedby.url?scp=0032839789&partnerID=8YFLogxK
M3 - Article
C2 - 10444631
AN - SCOPUS:0032839789
VL - 87
SP - 711
EP - 714
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 2
ER -