PT  - JOURNAL ARTICLE
AU  - A.M. Brackenbury
AU  - J.L. Malloy
AU  - L.A. McCaig
AU  - L-J. Yao
AU  - R.A.W. Veldhuizen
AU  - J.F. Lewis
TI  - Evaluation of alveolar surfactant aggregates <em>in vitro</em> and <em>in vivo</em>
AID  - 10.1183/09031936.02.00211202
DP  - 2002 Jan 01
TA  - European Respiratory Journal
PG  - 41--46
VI  - 19
IP  - 1
4099  - http://erj.ersjournals.com/content/19/1/41.short
4100  - http://erj.ersjournals.com/content/19/1/41.full
SO  - Eur Respir J2002 Jan 01; 19
AB  - In acute lung injury, a decrease in surface-active large aggregates and an increase in the less surface-active small surfactant aggregates are observed. The objective of the current study was to determine if the increase in small aggregates interfered with the function of large aggregates, thereby independently contributing to lung dysfunction. Isolated large aggregates, small aggregates, and large aggregate+small aggregate combinations were analysed for in vitro surface activity utilizing a pulsating bubble surfactometer. Subsequently, large aggregates, small aggregates, and large aggregate+small aggregate combinations were administered to surfactant-deficient, adult Sprague-Dawley rats. Physiological parameters were measured during 1 h of ventilation. After sacrifice, the whole lung lavage was analysed for protein concentration, and surface activity of the recovered large aggregates. The minimum surface tension of the large aggregate+small aggregate preparations (10 mN·m−1) was significantly higher than large aggregates alone (1 mN·m−1), but lower than small aggregates alone (21 mN·m−1) after 100 pulsations. In vivo, rats receiving large aggregates+small aggregates showed immediate increases in oxygenation, similar to animals given large aggregates, whereas animals given small aggregates and control animals maintained low oxygenation values. In conclusion, small aggregates interfered with large aggregates function in vitro, but this was not observed in vivo in this experimental model.