Dietary polyunsaturated fatty acids enhance hepatic AMP-activated protein kinase activity in rats

Biochem Biophys Res Commun. 2005 Jan 28;326(4):851-8. doi: 10.1016/j.bbrc.2004.11.114.

Abstract

Polyunsaturated fatty acids (PUFA) and a number of drugs (metformin, thiazolidinediones) and hormones (leptin, adiponectin) that activate AMP-activated protein kinase (AMPK) have been reported to improve insulin sensitivity. To determine whether PUFA activate AMPK, Sprague-Dawley rats were adapted to a 3h meal-feeding regimen using a fat-free diet (FFD) supplemented with fish oil (n-3) or triolein (n-9) for 7 days. No differences in hepatic AMPK activity were observed between the groups after 21h of fasting. On the other hand, hepatic AMPK phosphorylation was decreased in rats refed the FFD, the FFD+triolein, and the FFD+PUFA by 80%, 75%, and 50%, respectively, when assessed 2h after completion of a meal. In keeping with these changes, decreases in acetyl-CoA carboxylase phosphorylation and carnitine palmitoyl transferase-1 mRNA and increases in fatty acid synthase gene expression were greatest in rats fed the FFD and least in the PUFA-fed rats. The results indicate that dietary PUFA enhance hepatic AMPK activity in vivo, and implicate AMPK as a component of the nutrient-sensing mechanism through which dietary fatty acids and especially PUFA influence the regulation of hepatic lipid metabolism and gene expression.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • AMP-Activated Protein Kinases
  • Administration, Oral
  • Animals
  • Dietary Fats, Unsaturated / metabolism*
  • Enzyme Activation
  • Fatty Acids, Unsaturated / administration & dosage*
  • Gene Expression Regulation, Enzymologic / physiology
  • Liver / enzymology*
  • Male
  • Multienzyme Complexes / metabolism*
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proteins
  • Rats

Substances

  • Dietary Fats, Unsaturated
  • Fatty Acids, Unsaturated
  • Multienzyme Complexes
  • Proteins
  • SPAI-1 protein, Sus scrofa
  • Protein-Serine-Threonine Kinases
  • AMP-Activated Protein Kinases