EFFECT OF TRACHEAL SMOOTH-MUSCLE TONE ON COLLAPSIBILITY OF IMMATURE AIRWAYS
EFFECT OF TRACHEAL SMOOTH-MUSCLE TONE ON COLLAPSIBILITY OF IMMATURE AIRWAYS
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DOI：
10.1152/jappl.1988.65.2.863
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发表时间：
1988-08-01
影响因子：
3.3
通讯作者：
SHAFFER, TH
中科院分区：
文献类型：
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作者：
PENN, RB;WOLFSON, MR;SHAFFER, TH
为了测试平滑的小气囊张力对极不成熟的气道的影响，从妊娠114-121天的早产羔羊切除气管段（n = 19），并固定在充满Krebs溶液的室中。在对照组（C）和乙酰胆碱（ACh）给药后（实验组，E），分别通过改变跨壁压（30 - 0 mmHg和-30-0 mmHg）来测定膨胀（Si）和收缩（Sc）顺应性。然后通过气管腔引入流量（V 2-15 l/min），同时将腔室压力（Pc）从0增加到30 Torr，并记录C和E条件下的驱动压力（Pd）。气管被发现是非常顺应性的;在ACh给药后，Si和Sc均显著降低（P < 0.005）。在每个压缩压力和每个流量值下，ACh给药后对气流的阻力（R = Pd/V）也显著降低（P < 0.05）。这些结果表明，高度顺应性早产儿气管表现出类似于Starling电阻器的压力-流量特性，并且压缩压力的影响可能会被ACh诱导的平滑肌收缩减弱。这些结果与成年和新生动物的数据比较表明，气管力学和压力-流量关系以及平滑肌刺激改变气道功能的方式存在发育差异。
To test the influence of smooth msucle tone on extremely immature airways, tracheal segments (n = 19) were excised from premature lambs at 114-121 days gestation and mounted in a chamber filled with Krebs solution. Inflation (Si) and collapsing (Sc) compliance were detemrined by altering transmural pressure from 30 to 0 torr and -30 to 0 torr, respectively, both during control (C) and after acetylcholine (ACh) administration (experimental, E). Flow (.ovrhdot.V 2-15 l/min) was then introduced through the tracheal lumen while chamber pressure (Pc) was increased from 0 to 30 Torr and driving pressure (Pd) was recorded for both C and E conditions. Tracheae were found to be extremely compliant; both Si and Sc were significantly (P < 0.005) lower after ACh administration. Resistance to airflow (R = Pd/.ovrhdot.V) was also significantly (P < 0.05) lower after ACh administration at each compressive pressure and each flow value. These results suggest that the highly compliant preterm trachea exhibits pressure-flow characteristics similar to a Starling resistor, and the effects of compressive pressures may be attenuated by ACh-induced smooth muscle contraction. Comparison of these results with data from adult and newborn animals suggests a developmental difference in tracheal mechanics and pressure-flow relationships, as well as in the way airway function is altered by smooth muscle stimulation.