Description
Apolipoprotein A-IV (ApoA-IV), first discovered in rat plasma in the 1970s , is a 46 kD glycoprotein with relatively high concentrations in plasma (15–37 mg/dL) . It is expressed predominantly in the mammalian small intestine (with highest expression in the duodenum), and also expressed in rodent liver at lower levels. Sensing lipid absorption in enterocytes , ApoA-IV is synthesized and packaged with lipids and other apolipoproteins into chylomicrons and secreted through the lymphatic system into the blood. Once there, as a member of exchangeable apolipoproteins, ApoA-IV dissociates from chylomicrons and transfers to HDL (high density lipoprotein) particles or circulates in lipid-free form .ApoA-IV may protect against atherosclerosis , mediate reverse cholesterol transport , act as an anti-inflammatory agent and modulate intestinal lipid absorption .