triolein and Respiratory-Insufficiency

We hypothesized that leukotrienes might contribute to the pathophysiology of acute lung injury induced by oleic acid. Oleic acid (2-20 mg.kg-1.h-1), LY171883 [leukotriene (LT) D4/LTE4 receptor antagonist, 10 mg/kg + 1 mg.kg-1.h-1] + oleic acid (10 mg.kg-1. h-1), or triolein (20 mg.kg-1.h-1) were infused intravenously into anesthetized pigs. Treatment with the cyclooxygenase inhibitor was designed to possibly enhance LT release. Bronchoalveolar lavage fluid concentrations of LTB4, LTC4, LTD4, and LTE4 were measured by reverse-phase high-performance liquid chromatography and radioimmunoassay. Oleic acid caused dose-related hypoxemia and pulmonary hypertension and increased pulmonary vascular resistance, lung water, and alveolar-capillary membrane permeability. Bronchoalveolar lavage fluid levels of LTB4, LTC4, LTD4, and LTE4 showed no significant changes in oleic acid- or indomethacin + oleic acid-treated pigs, compared with triolein-treated controls. Indomethacin modestly attenuated the oleic acid-induced hypoxemia and the early increases (i.e., 0-0.5 h) in mean pulmonary arterial pressure and pulmonary vascular resistance. In contrast, LY171883 provided no protection against any oleic acid-induced cardiopulmonary effect (measured or calculated). We conclude that LTs are not likely to be important mediators of oleic acid-induced lung injury in the pig.

Topics: Acetophenones; Acute Disease; Animals; Autacoids; Blood Pressure; Bronchoalveolar Lavage Fluid; Indomethacin; Leukotriene B4; Leukotriene E4; Leukotrienes; Lung; Oleic Acid; Oleic Acids; Respiratory Insufficiency; SRS-A; Swine; Tetrazoles; Triolein; Vascular Resistance

Pulmonary haemodynamic and arterial blood gas changes were measured in dogs subjected to either an intravenous injection of triolein or external trauma, which produced fractures of the ipsilateral femur, tibia and fibula. Musculoskeletal trauma resulted in pulmonary vasoconstriction followed by vasodilatation, arterial hypoxia with a pulmonary shunt of 30% and a 20% decrease in systemic oxygen delivery. Lipid injection produced an increased pulmonary vascular resistance, but no significant hypoxia, pulmonary shunting or inadequate tissue oxygenation. We therefore suggest that pulmonary fat embolism does not account for the pulmonary insufficiency following musculoskeletal trauma.

Topics: Animals; Blood Gas Analysis; Dogs; Embolism, Fat; Femoral Fractures; Fibula; Fractures, Bone; Fractures, Closed; Hemodynamics; Muscles; Pulmonary Valve Insufficiency; Respiratory Insufficiency; Tibial Fractures; Triolein