Abstract
Parenchymal tissue strips have been used to investigate the mechanical behavior of the lung parenchyma. We questioned whether the relative amounts of alveolar, blood vessel, and bronchial walls would be important when the contractile response of parenchymal strips from Sprague-Dawley rats was studied. One group of strips was cut from the subpleural edge and another from between 1 and 3 mm proximal to the pleura. Strips were suspended in an organ hath filled with Krebs solution (37°C, pH 7.4) bubbled with 95% O2- 5% CO2. Resting tension (T) was set at 1.1 g, and sinusoidal oscillations of 2.5% resting length at a frequency of l Hz were applied. Measurements of length and T were recorded during baseline conditions and after acetylcholine (10-3 M) was added to the bath. Elastance, resistance, and hysteresivity (the ratio of the energy dissipated to that conserved) were calculated. Strips were fixed in Formalin at a T of 1 g, histological sections were prepared, and the fractional areas of alveolar, blood vessel, and bronchial walls were measured by using point counting. Significant differences were found between the two groups of strips in the acetylcholine response and anatomic makeup. The magnitude of the changes of all the mechanical parameters were correlated with the volume proportions of the different anatomic constituents when all the strips were plotted together but not when the subpleural strips were considered alone. We conclude that subpleural parenchymal strips are a sound model of parenchymal lung behavior. When more proximal strips are studied, the amount of bronchial wall may play an important role in determining the hysteretic response.
| Original language | English |
|---|---|
| Pages (from-to) | 66-72 |
| Number of pages | 7 |
| Journal | Journal of Applied Physiology |
| Volume | 79 |
| Issue number | 1 |
| Publication status | Published - 1995 |
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Keywords
- acetylcholine
- airway smooth muscle
- hysteresis
- structure-function correlation
ASJC Scopus subject areas
- Endocrinology
- Physiology
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation
Cite this
Does the anatomic makeup of parenchymal lung strips affect oscillatory mechanics during induced constriction? / Salerno, F. G.; Dallaire, M.; Ludwig, M. S.
In: Journal of Applied Physiology, Vol. 79, No. 1, 1995, p. 66-72.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Does the anatomic makeup of parenchymal lung strips affect oscillatory mechanics during induced constriction?
AU - Salerno, F. G.
AU - Dallaire, M.
AU - Ludwig, M. S.
PY - 1995
Y1 - 1995
N2 - Parenchymal tissue strips have been used to investigate the mechanical behavior of the lung parenchyma. We questioned whether the relative amounts of alveolar, blood vessel, and bronchial walls would be important when the contractile response of parenchymal strips from Sprague-Dawley rats was studied. One group of strips was cut from the subpleural edge and another from between 1 and 3 mm proximal to the pleura. Strips were suspended in an organ hath filled with Krebs solution (37°C, pH 7.4) bubbled with 95% O2- 5% CO2. Resting tension (T) was set at 1.1 g, and sinusoidal oscillations of 2.5% resting length at a frequency of l Hz were applied. Measurements of length and T were recorded during baseline conditions and after acetylcholine (10-3 M) was added to the bath. Elastance, resistance, and hysteresivity (the ratio of the energy dissipated to that conserved) were calculated. Strips were fixed in Formalin at a T of 1 g, histological sections were prepared, and the fractional areas of alveolar, blood vessel, and bronchial walls were measured by using point counting. Significant differences were found between the two groups of strips in the acetylcholine response and anatomic makeup. The magnitude of the changes of all the mechanical parameters were correlated with the volume proportions of the different anatomic constituents when all the strips were plotted together but not when the subpleural strips were considered alone. We conclude that subpleural parenchymal strips are a sound model of parenchymal lung behavior. When more proximal strips are studied, the amount of bronchial wall may play an important role in determining the hysteretic response.
AB - Parenchymal tissue strips have been used to investigate the mechanical behavior of the lung parenchyma. We questioned whether the relative amounts of alveolar, blood vessel, and bronchial walls would be important when the contractile response of parenchymal strips from Sprague-Dawley rats was studied. One group of strips was cut from the subpleural edge and another from between 1 and 3 mm proximal to the pleura. Strips were suspended in an organ hath filled with Krebs solution (37°C, pH 7.4) bubbled with 95% O2- 5% CO2. Resting tension (T) was set at 1.1 g, and sinusoidal oscillations of 2.5% resting length at a frequency of l Hz were applied. Measurements of length and T were recorded during baseline conditions and after acetylcholine (10-3 M) was added to the bath. Elastance, resistance, and hysteresivity (the ratio of the energy dissipated to that conserved) were calculated. Strips were fixed in Formalin at a T of 1 g, histological sections were prepared, and the fractional areas of alveolar, blood vessel, and bronchial walls were measured by using point counting. Significant differences were found between the two groups of strips in the acetylcholine response and anatomic makeup. The magnitude of the changes of all the mechanical parameters were correlated with the volume proportions of the different anatomic constituents when all the strips were plotted together but not when the subpleural strips were considered alone. We conclude that subpleural parenchymal strips are a sound model of parenchymal lung behavior. When more proximal strips are studied, the amount of bronchial wall may play an important role in determining the hysteretic response.
KW - acetylcholine
KW - airway smooth muscle
KW - hysteresis
KW - structure-function correlation
UR - http://www.scopus.com/inward/record.url?scp=0029113087&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029113087&partnerID=8YFLogxK
M3 - Article
C2 - 7559249
AN - SCOPUS:0029113087
VL - 79
SP - 66
EP - 72
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 1
ER -