TY - JOUR
T1 - Further examination of alveolar septal adaptation to left pneumonectomy in the adult lung
AU - Hsia, Connie C W
AU - Johnson, Robert L.
N1 - Funding Information:
This work was supported by National Institutes of Health grants R01 HL045716, HL040070, HL054060 and HL062873. The contents of this article are solely the responsibility of the authors and do not necessarily represent the official views of the National Heart, Lung, and Blood Institute or of the National Institutes of Health.
PY - 2006/4/28
Y1 - 2006/4/28
N2 - Recent data from our laboratory are presented concerning alveolar septal adaptation following 42-45% lung resection by left pneumonectomy (PNX) in adult foxhounds compared to sham-operated control animals. Results confirm our previous conclusion that compensation in the remaining lung occurs without a net growth of additional alveolar septal tissue. The major ultrastructural responses are (a) alveolar capillary distention, which recruits capillary blood volume and surface area, leading to a 30-50% increase in lung diffusing capacity estimated by morphometry, a magnitude similar to that measured by physiologic methods; (b) a selectively increased volume of type 2 alveolar epithelial cells. These data, taken together with the balanced compensatory growth of alveolar septal cells observed in adult dogs following 55-58% lung resection by right PNX, support a graded alveolar cellular response to chronic mechanical strain with the alveolar epithelial cells being activated first; as strain increases further with greater lung resection other alveolar cells also become activated leading to an overt increase in septal tissue volume. The spatial distribution of lobar mechanical strain and lobar tissue volume assessed by high resolution computed tomography was markedly non-uniform after PNX, suggesting possible non-uniform distribution of alveolar cellular response. The sequential activation of physiologic recruitment and cellular adaptation confer additive functional benefits that optimize long-term exercise performance after PNX.
AB - Recent data from our laboratory are presented concerning alveolar septal adaptation following 42-45% lung resection by left pneumonectomy (PNX) in adult foxhounds compared to sham-operated control animals. Results confirm our previous conclusion that compensation in the remaining lung occurs without a net growth of additional alveolar septal tissue. The major ultrastructural responses are (a) alveolar capillary distention, which recruits capillary blood volume and surface area, leading to a 30-50% increase in lung diffusing capacity estimated by morphometry, a magnitude similar to that measured by physiologic methods; (b) a selectively increased volume of type 2 alveolar epithelial cells. These data, taken together with the balanced compensatory growth of alveolar septal cells observed in adult dogs following 55-58% lung resection by right PNX, support a graded alveolar cellular response to chronic mechanical strain with the alveolar epithelial cells being activated first; as strain increases further with greater lung resection other alveolar cells also become activated leading to an overt increase in septal tissue volume. The spatial distribution of lobar mechanical strain and lobar tissue volume assessed by high resolution computed tomography was markedly non-uniform after PNX, suggesting possible non-uniform distribution of alveolar cellular response. The sequential activation of physiologic recruitment and cellular adaptation confer additive functional benefits that optimize long-term exercise performance after PNX.
KW - Alveolar capillary recruitment
KW - Compensatory lung growth
KW - Diffusing capacity
KW - High resolution computed tomography
KW - Lung resection
KW - Morphometry
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U2 - 10.1016/j.resp.2006.01.013
DO - 10.1016/j.resp.2006.01.013
M3 - Article
C2 - 16563882
AN - SCOPUS:33645985494
SN - 1569-9048
VL - 151
SP - 167
EP - 177
JO - Respiratory Physiology and Neurobiology
JF - Respiratory Physiology and Neurobiology
IS - 2-3
ER -