Pulmonary neutral fat embolism in dogs.

Twenty-two adult dogs were each given a single, 30-minute injection of 1.5 ml/kg body weight of pure triolein, and their pulmonary, hepatic, renal, and cerebral morphology was observed for 1, 2, 3, 4, 5, 6, 15, 24, and 48 hours; 3,4, and 5 days; 1 and 2 weeks; and 1 month after the injection. A picture of massive capillary occlusion by lipid droplets was followed by rapidly resolvable inflammatory pneumopathy of granulomatous type, leaving a normal lung at the end of the experiment. The cleaning of the capillaries may be attributed to the mechanical action of the blood flow and to the inflammatory reaction with evacuation of necrotic cells via the bronchial route. Transient pulmonary edema is attributed to increased pulmonary arterial pressure. There was no intravacular coagulation. The few pulmonary lesions observed after the triolein injection suggest that the chemical theory of neutral fat hydrolysis by pulmonary lipase and the toxicity of free fatty acids that are released should be reconsidered

Embolic pneumopathy induced by oleic acid. A systematic morphologic study.

This paper presents a systematic study of acute and chronic pulmonary lesions resulting from a single intravenous injection of oleic acid and a new fibrosis lung model is proposed: pulmonary interstitial fibrosis is obtained by means of a number of oleic acid intravenous injections. Nineteen adult dogs received 0.045 g/kg or 0.09 g/kg of oleic acid. A systematic morphologic study was carried out after 1, 2, 3, 4, 6, 12, 24, and 48 hours and 1, 2 and 4 weeks. Eleven other adult dogs received weekly one injection of 0.09 g/kg of pure oleic acid over a period of 1 to 3 months. Examination of the lung was carried out by means of light and electron microscopy and morphometry. An early stage characterized by the formation of thrombosis and cellular necrosis was followed by a repair stage with the proliferation of Type 2 cells and fibrotic foci in the subpleural areas. Lipid staining with Sudan IV allowed the onset and disappearance of lipid-laden macrophages to be ascertained. The late stage showed pulmonary fibrosis. The extent of the lesions is related to the number of oleic acid injections. Since interstitial pulmonary fibrosis invariably appeared, and only 2 dogs out of 11 died, the model is satisfactory for pathologist and physiologist