TY - JOUR
T1 - Enhanced alveolar growth and remodeling in Guinea pigs raised at high altitude
AU - Hsia, Connie C W
AU - Carbayo, Juan J Polo
AU - Yan, Xiao
AU - Bellotto, Dennis J.
N1 - Funding Information:
We thank Dr. Frank L. Powell and the staff of the University of California, White Mountain Research Station for their support and assistance that made this study possible. We also thank Deborah C. Hogg and Jean Wang for their expert technical assistance. This research was supported by NHLBI R01 HL45716, HL40070, HL54060 and HL62873.
PY - 2005/5/12
Y1 - 2005/5/12
N2 - To examine the effects of chronic high altitude (HA) exposure on lung structure during somatic maturation, we raised male weanling guinea pigs at HA (3800 m) for 1, 3, or 6 months, while their respective male littermates were simultaneously raised at low altitude (LA, 1200 m). Under anaesthesia, airway pressure was measured at different lung volumes. The right lung was fixed at a constant airway pressure for morphometric analysis under light and electron microscopy. In animals raised at HA for 1 month, lung volume, alveolar surface area and alveolar-capillary blood volume (Vc) were elevated above LA control values. Following 3-6 months of HA exposure, increases in lung volume and alveolar surface area persisted while the initial increase in Vc normalized. Additional adaptation occurred, including a higher epithelial cell volume, septal tissue volume and capillary surface area, a lower alveolar duct volume and lower harmonic mean diffusion barrier resulting in higher membrane and lung diffusing capacities. These data demonstrate enhanced alveolar septal growth and progressive acinar remodeling during chronic HA exposure with long-term augmentation of alveolar dimensions as well as functional compensation in lung compliance and diffusive gas transport.
AB - To examine the effects of chronic high altitude (HA) exposure on lung structure during somatic maturation, we raised male weanling guinea pigs at HA (3800 m) for 1, 3, or 6 months, while their respective male littermates were simultaneously raised at low altitude (LA, 1200 m). Under anaesthesia, airway pressure was measured at different lung volumes. The right lung was fixed at a constant airway pressure for morphometric analysis under light and electron microscopy. In animals raised at HA for 1 month, lung volume, alveolar surface area and alveolar-capillary blood volume (Vc) were elevated above LA control values. Following 3-6 months of HA exposure, increases in lung volume and alveolar surface area persisted while the initial increase in Vc normalized. Additional adaptation occurred, including a higher epithelial cell volume, septal tissue volume and capillary surface area, a lower alveolar duct volume and lower harmonic mean diffusion barrier resulting in higher membrane and lung diffusing capacities. These data demonstrate enhanced alveolar septal growth and progressive acinar remodeling during chronic HA exposure with long-term augmentation of alveolar dimensions as well as functional compensation in lung compliance and diffusive gas transport.
KW - Alveolar duct
KW - Alveolar surface area
KW - Alveolar tissue volume
KW - Diffusion barrier
KW - Hypoxia
KW - Lung diffusing capacity
KW - Lung growth
KW - Membrane diffusing capacity
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U2 - 10.1016/j.resp.2005.02.001
DO - 10.1016/j.resp.2005.02.001
M3 - Article
C2 - 15848128
AN - SCOPUS:17444362233
SN - 1569-9048
VL - 147
SP - 105
EP - 115
JO - Respiratory Physiology and Neurobiology
JF - Respiratory Physiology and Neurobiology
IS - 1
ER -