Reticulum-endothelial system

Figure 25-2. The formation and secretion of (A) chylomicrons by an intestinal cell and (B) very low density lipoproteins by a hepatic cell. (RER, rough endoplasmic reticulum SER, smooth endoplasmic reticulum G, Golgi apparatus N, nucleus C, chylomicrons VLDL, very low density lipoproteins E, endothelium SD, space of Disse, containing blood plasma.) Apolipoprotein B, synthesized in the RER, is incorporated into lipoproteins in the SER, the main site of synthesis of triacylglycerol. After addition of carbohydrate residues in G, they are released from the cell by reverse pinocytosis. Chylomicrons pass into the lymphatic system. VLDL are secreted into the space of Disse and then into the hepatic sinusoids through fenestrae in the endothelial lining.

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