Effect of quinacrine on lipid content of bronchoalveolar lavage fluid in guinea pigs sensitized to ovalbumin.

In both ovalbumin-sensitized and ovalbumin-challenged guinea pigs, the phospholipid content of bronchoalveolar lavage fluid is decreased with respect to that of controls. In the sensitized guinea pig, the activity of lung membrane phospholipase is increased and the phospholipid content of lung membranes is decreased. In determining whether alveolar phospholipids are metabolized in a similar way, quinacrine, a phospholipase A2 inhibitor, was administered (10 mg/kg intravenously) to control, sensitized, and challenged animals before inhalation of ovalbumin. Pulmonary ventilation and lung mechanics were measured both before and after the injection of quinacrine and inhalation of ovalbumin. Phospholipid content was measured in the bronchoalveolar lavage fluid. In the control and sensitized groups quinacrine had no effect on pulmonary ventilation and lung mechanics, and in the challenged group it reduced the intensity of anaphylactic bronchospasm. In control animals it did not change the phospholipid content, whereas in the sensitized and challenged animals it suppressed the decrease of phospholipid content. The results suggest that in the sensitized and challenged guinea pigs alveolar phospholipids are degraded by phospholipase A2, the activity of which is increased.