Monitoring the capillary-alveolar leakage in an A.R.D.S. model using broncho-alveolar lavage.
OBJECTIVE
We developed a modified broncho-alveolar lavage (BAL) technique in order to perform repeated measurements of capillary-alveolar leakage of a macromolecule in oleic acid (OA)-induced lung injury.


METHODS
BAL was performed in anesthetized dogs in a closed lung sampling site, using a bronchoscope fitted with an inflatable cuff. Fluorescein-labeled Dextran (FITC-D70) was continuously infused and its concentration measured in plasma and BAL fluid. A two-compartment model (blood and alveoli) was used to calculate K(AB), the transport-rate coefficient of FITC-D70 from blood to alveoli. K(AB) was estimated every 15 minutes over three hours.


RESULTS
K(AB), close to zero at base-line both in control (n = 3) and in OA-injured lungs (n = 7), reached a peak in permeability 30 minutes after the induction of OA injury (K(AB) = 1.43 +/- 0.31 . 10(- 3) . minutes(- 1)), followed by a slow recovery.


CONCLUSIONS
We conclude that this technique allows the monitoring of capillary-alveolar transport of macromolecules in in vivo experimental models. This monitoring may prove useful to study the mechanisms of the exudative stage of acute lung injury and to test therapies aimed at slowing the alveolar accumulation of plasma proteins and procoagulant factors that contribute to alveolar fibrosis.
Briot
Raphael
R
Laboratoire TIMC, Unité Mixte de Recherche 5525 du Centre National de Recherche Scientifique, Université Joseph Fourier, Grenoble, France. RBriot@chu-grenoble.fr
Bayat
Sam
S
Anglade
Daniel
D
Martiel
Jean-Louis
JL
Grimbert
Francis
F
D000818:Animals; D018893:Bronchoalveolar Lavage / Q000295:instrumentation* / Q000379:methods*; D020680:Bronchoscopes; D002196:Capillaries / Q000502:physiology; D003911:Dextrans / Q000493:pharmacokinetics; D004195:Disease Models, Animal; D004285:Dogs; D015633:Extravascular Lung Water / Q000378:metabolism; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D008954:Models, Biological; D019301:Oleic Acid; D011506:Proteins / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000098:blood supply* / Q000503:physiopathology*; D012128:Respiratory Distress Syndrome / Q000139:chemically induced / Q000503:physiopathology*
D003911:Dextrans; D011506:Proteins; C015219:fluorescein isothiocyanate dextran; D019301:Oleic Acid; D016650:Fluorescein-5-isothiocyanate