The role of free fatty acids in pulmonary fat embolism.

Pulmonary embolism was produced in rabbits by the intravenous injection of 0-5 ml/kg body-weight of glycerol trioleate and mineral oil. Lung weight, pulmonary total lipid, esterified and free fatty acids content increased in both groups, but the concentration of free fatty acids increased only in the animals injected with neutral fat. Mineral oil injection produced stasis and haemorrhage; neutral fat produced exudation of serous liquid into the alveoli and an inflammatory reaction. There are definite differences between the pulmonary effects of mineral oil embolism and neutral fat embolism. The observations support the assumption that pulmonary changes in fat embolism are due to the toxic effect of free fatty acids liberated from the embolized neutral fat.