Lipid absorption, transport and hepatic assimilation studied with electron microscopy

¹ Department of Pathology, The University of Texas Southwestern Medical School, Dallas, Texas

An electron microscopic study of intestine and liver in rats ingesting a high-lipid diet or receiving corn oil by stomach tube was carried out. Studies of the intestinal phase of lipid absorption in rats showed what appears to be the direct transfer of particles across the cell membrane confirming the postulate that some of the process of lipid absorption involves triglyceride particles. Lipid droplets, representing chylomicrons were identified in hepatic sinusoids. They were traced into the pericellular space of Disse, which they had entered through the wide pore spaces in the sinusoidal endothelial cytoplasm. Lipid particles were also observed in different stages of direct transfer across the hepatic parenchymal cell membrane, and their formation of larger cytoplasmic lipid droplets within the cytoplasm of liver cells. This mechanism is proposed as a major device of the body in dispersing the lipemia which occurs after the ingestion of a fat meal.