Phospholipids
Phospholipids are found in foods of both animal and plant origin although in relatively small amounts. The main dietary phospholipid is lecithin. and, like cholesterol, it becomes mixed with endogenous leci thin both in the intestinal lumen (from bile) and inside the mucosal cell (synthesized).
Before absorption, lecithin and other gylcerophospholipids are hydrolyzed to lysophospholipids by pancreatic phospholipase A, which removes the fatty acid in the 2-position of the glycerophosphatides. Lysolecithin and other lysophosphatides participate in micelle formation in the intestine and are absorbed by passive diffusion like the other lipid digestion products. Lysophospholipids undergo extensive breakdown and resynthesis in the mucosal cell. Some parts of the molecule may be found in triglycerides or in other phospholipids manufactured in the cell. Phospholipids are important structural components of the triglyceride transporting chylomicrons and other lipoproteins and are actively synthesized in the mucosal cell.
