Zhang S, Garbutt V, McBride J T
Strong Children's Research Center, University of Rochester, School of Medicine and Dentistry, New York 14642, USA.
J Appl Physiol (1985). 1996 Oct;81(4):1471-6. doi: 10.1152/jappl.1996.81.4.1471.
To investigate the relationship between strain and postnatal lung growth, two groups of weanling ferrets were tracheotomized: the study group was exposed for 2 wk to a continuous positive airway pressure (CPAP) of 6 cmH2O and the other group was exposed to atmospheric pressure (control). Total lung capacity after 2 wk was approximately 40% higher in the CPAP-exposed animals than in the control animals (n = 19 for the control group and 18 for the study group; P < 0.01). CPAP exposure was also associated with increases in lung weight and total lung protein and DNA contents. Lung recoil, measured in a subgroup of animals, was characterized by air-filled and saline-filled static expiratory pressure-volume curves. Neither in the air-filled lungs nor saline-filled lungs was there a significant difference between CPAP-exposed and control animals in lung recoil at equal fractions of total lung capacity. These data indicate that mechanical strain was associated with an acceleration of lung growth in immature ferrets. The preservation of volume-corrected lung recoil and the expected contribution of surface forces and tissue forces to lung recoil in CPAP-exposed animals suggest that this response did not involve simple lung distension but included a remodeling of the lung parenchyma.
为了研究应变与出生后肺生长之间的关系，对两组断奶雪貂进行气管切开术：研究组持续2周暴露于6 cmH₂O的持续气道正压（CPAP）下，另一组暴露于大气压下（对照组）。2周后，暴露于CPAP的动物的肺总量比对照动物高约40%（对照组n = 19，研究组n = 18；P < 0.01）。暴露于CPAP还与肺重量、肺总蛋白和DNA含量的增加有关。在一组亚组动物中测量的肺回缩，通过充空气和充生理盐水的静态呼气压力-容积曲线来表征。在总肺容量相同比例时，暴露于CPAP的动物与对照动物相比，无论是在充空气的肺还是充生理盐水的肺中，肺回缩均无显著差异。这些数据表明，机械应变与未成熟雪貂肺生长加速有关。在暴露于CPAP的动物中，体积校正后的肺回缩得以保留，且表面力和组织力对肺回缩有预期贡献，这表明这种反应并非单纯涉及肺扩张，而是包括肺实质的重塑。
