Long-term continuous intralipid infusion in the thoracic duct in rats

Intralipid was continuously infused into the thoracic duct for 12 days in rats. All remained clinically fit and had satisfactory weight gain only for the first week. Autopsy showed significantly increased lung weight in all rats and in some there were lymphatic fistulas and dilated thoracic duct. Microscopy revealed fat droplets, vascular changes and thickening of alveolar septa in the lungs. Epithelioid cell clusters were found in liver and spleen in some of the rats and Kupffer cell increase in most. Thus commercially available fat emulsion for parenteral use, when delivered by the natural route for natural chylomicrons, caused undesirable derangements in rats.