Apolipoprotein A-IV, food intake, and obesity.

Abstract

Apolipoprotein A-IV (apo A-IV) is secreted by the intestine associated with chylomicron. Intestinal apo A-IV synthesis is stimulated by fat absorption, which is probably mediated by chylomicron formation. The stimulation of apo A-IV synthesis in the jejunum and ileum is attenuated by intravenous leptin infusion. Intestinal apo A-IV synthesis is also stimulated by a factor from the ileum, probably peptide tyrosine-tyrosine (PYY), which has been demonstrated to affect satiety. Apo A-IV has been proposed to physiologically control food intake, a function not shared by apo A-I, and this inhibitory effect is centrally mediated. Recently, apo A-IV was demonstrated in the hypothalamus. The hypothalamic apo A-IV level was reduced by food deprivation and restored by lipid feeding. Intracerebroventricular administration of apo A-IV antiserum increased feeding and decreased the hypothalamic apo A-IV mRNA level, implying that feeding is normally limited by endogenous apo A-IV. Central administration of neuropeptide Y (NPY) significantly increased hypothalamic apo A-IV mRNA levels in a dose-dependent manner. The stimulation of intestinal synthesis and secretion of apo A-IV by lipid absorption are rapid; thus, apo A-IV is capable of short-term regulation of food intake. Evidence also suggests apo A-IV's involvement in the long-term regulation of food intake and body weight. Chronic ingestion of high fat blunts the hypothalamic apo A-IV response to lipid feeding and may therefore explain why chronic intake of high fat predisposes animals and humans to obesity.

• Authors: Patrick Tso, Min Liu
• Journal: Physiology & behavior (Physiol Behav) Vol. 83 Issue 4 Pg. 631-43 (Dec 30 2004) ISSN: 0031-9384 [Print] United States
• PMID: 15621069 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S., Review)

Chemical References

• Apolipoproteins A
• Dipeptides
• Leptin
• Neuropeptide Y
• tyrosyltyrosine

Topics

• Adrenalectomy (methods)
• Animals
• Apolipoproteins A (genetics, metabolism)
• Circadian Rhythm (physiology)
• Dipeptides (pharmacology)
• Dose-Response Relationship, Drug
• Eating (drug effects, physiology)
• Humans
• Hypothalamus (drug effects, metabolism)
• Intestine, Small (anatomy & histology, drug effects, metabolism)
• Leptin (pharmacology)
• Lipid Metabolism
• Neuropeptide Y (administration & dosage)
• Obesity (metabolism)
• Vagotomy (methods)