Broussard David, Larson Janet E, Cohen J Craig, Lundblad Lennart K A
Department of Anesthesiology, Ochsner Clinic Foundation, New Orleans, Louisiana, USA.
Exp Lung Res. 2006 Jun-Jul;32(6):263-73. doi: 10.1080/01902140600817549.
The rat lung undergoes rapid changes during the first several weeks of life. Respiratory function on neonatal rats was performed to determine if physiologic alterations coincides with classically described lung growth, and morphologic and morphometric changes. The authors examined respiratory mechanics during normal postnatal lung development in the rat utilizing both a forced oscillation technique, which partitions the mechanical properties of the lung tissue from the airways, as well as pressure-volume (PV) curves to assess lung elasticity. Respiratory function testing was performed on each postnatal days of life 10 to 20. The PV curves were characterized by a leftward shift over days 10 to 16, followed by a shift back to the right over days 17 to 20. Both tissue damping (G) and elastance (H) decreased from days of life 10 to 15, and then equilibrated from days 15 to 21. Hysteresivity (=G/H) at positive end-expiratory pressure (PEEP) = 1 and 3 cm H2O declined significantly with age. The effect of PEEP was significantly greater in the younger animals than in the older animals. The respiratory function assessments coincide well with the classically described periods of lung growth. These studies provide a normal baseline for correlating changes in structural with respiratory function.
大鼠肺在出生后的最初几周内会经历快速变化。对新生大鼠进行呼吸功能测试，以确定生理改变是否与经典描述的肺生长以及形态学和形态计量学变化相一致。作者利用强迫振荡技术（该技术可将肺组织与气道的机械特性区分开来）以及压力-容积（PV）曲线来评估肺弹性，从而研究大鼠出生后正常肺发育过程中的呼吸力学。在出生后第10至20天的每一天都进行呼吸功能测试。PV曲线的特征是在第10至16天向左移动，然后在第17至20天又向右移动。从出生后第10至15天，组织阻尼（G）和弹性（H）均下降，然后在第15至21天达到平衡。在呼气末正压（PEEP）= 1和3 cm H2O时，滞后率（= G / H）随年龄显著下降。PEEP对年幼动物的影响明显大于对年长动物的影响。呼吸功能评估与经典描述的肺生长时期非常吻合。这些研究为将结构变化与呼吸功能相关联提供了一个正常基线。
