Send to

Choose Destination
Am J Physiol Gastrointest Liver Physiol. 2012 Mar 15;302(6):G628-36. doi: 10.1152/ajpgi.00225.2011. Epub 2011 Dec 29.

Apolipoprotein A-IV regulates chylomicron metabolism-mechanism and function.

Author information

Department of Pathology and Laboratory Medicine, University of Cincinnati, OH 45237, USA.


Dietary fat is an important mediator of atherosclerosis and obesity. Despite its importance in mediating metabolic disease, there is still much unknown about dietary fat absorption in the intestine and especially the detailed biological roles of intestinal apolipoproteins involved in that process. We were specifically interested in determining the physiological role of the intestinal apolipoprotein A-IV (A-IV) using A-IV knockout (KO) mice. A-IV is stimulated by fat absorption in the intestine and is secreted on nascent chylomicrons into intestinal lymph. We found that A-IV KO mice had reduced plasma triglyceride (TG) and cholesterol levels and that this hypolipidemia persisted on a high-fat diet. A-IV KO did not cause abnormal intestinal lipid absorption, food intake, or adiposity. Additionally, A-IV KO did not cause abnormal liver TG and cholesterol metabolism, as assessed by measuring hepatic lipid content, lipogenic and cholesterol synthetic gene expression, and in vivo VLDL secretion. Instead, A-IV KO resulted in the secretion of larger chylomicrons from the intestine into the lymph, and those chylomicrons were cleared from the plasma more slowly than wild-type chylomicrons. These data suggest that A-IV has a previously unknown role in mediating the metabolism of chylomicrons, and therefore may be important in regulating plasma lipid metabolism.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Atypon Icon for PubMed Central
Loading ...
Support Center