[Effects of sensitization to ovalbumin on the lipid content of the bronchoalveolar lavage fluid in guinea pigs].

Four groups of guinea-pigs were studied (l1: control, l2: sensitized to ovalbumin, l3: sensitized and challenged by aerosol of ovalbumin, l4: challenged by aerosol of histamine). In urethane anaesthetized guinea-pigs, pulmonary resistances and dynamic compliance were measured (before and after aerosol of ovalbumin in l3 and aerosol of histamine in l4). The lungs were removed and the static pressure-volume curves were performed to determine lung compliance. In the pulmonary lavage fluids, surface tension and total fatty acids and phospholipids were measured by Cahn's electrobalance and gas chromatography respectively. In l2 guinea-pigs, the mean value of total fatty acids and of phospholipids was significantly decreased in pulmonary lavage fluid, by 24.5% and 40.2% respectively. Surface tension was increased while lung mechanics was identical to control. In l3 guinea-pigs, the mean value of total fatty acids and of phospholipids was significantly decreased in pulmonary lavage fluids, by 55.7% and 53.2% respectively. Surface tension was increased. In vivo, lung mechanics was changed: dynamic compliance decreased, pulmonary resistances increased. Pressure-volume curves were flattened and pulmonary compliance of isolated lungs was decreased since bronchial obstruction remained after death. In l4 guinea-pigs, the mean value of total fatty acids and of phospholipids was increased in pulmonary lavage fluid but not significantly, by 26.6% and 9.2%. Surface tension was not changed. Lung mechanics was very significantly affected by bronchospasm, but after death the mechanics of the isolated lung and of control lung was identical. Finally, the decrease of surface-active lipids in pulmonary lavage fluid originates in the sensitization and is enhanced by antigen-induced bronchial anaphylaxis but not by histamine-induced bronchospasm.