Involvement of lipogenesis in the lower VLDL secretion induced by oligofructose in rats.
Dietary supplementation with oligofructose (OFS; 100 g/kg), a non-digestible oligomer of beta-D-fructose, decreases serum triacylglycerols in serum and VLDL of rats. In order to investigate the role of hepatic metabolism in the hypolipidaemic effect of OFS, male Wistar rats were fed on a standard diet with or without 100 g Raftilose P95/kg as OFS source for 30 d. OFS feeding (1) significantly decreased triacylglycerol and phospholipid concentrations in both blood and liver, (2) increased the glycerol-3-phosphate liver content but decreased the hepatic activity of glycerol-3-phosphate acyltransferase (EC 2.3.1.15), suggesting a decrease in acylglycerol synthesis, (3) did not affect the blood non-esterified fatty acid concentrations, but (4) reduced by 54% the capacity of isolated hepatocytes to synthesize and secrete triacylglycerols from labelled acetate; the activity of fatty acid synthase, a key lipogenic enzyme was also significantly decreased. These findings suggest that OFS decreases serum triacylglycerols by reducing de novo fatty acid synthesis in the liver; the lower insulin level in the serum of OFS-fed rats could explain, at least partly, the metabolic effect induced by such non-digestible carbohydrates.
Kok
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N
Déparetment des Sciences Pharmaceutiques. Université Catholique de Louvain, Brussels, Belgium.
Roberfroid
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M
Robert
A
A
Delzenne
N
N
D000818:Animals; D005227:Fatty Acids / Q000378:metabolism; D005632:Fructose / Q000008:administration & dosage*; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000378:metabolism; D008055:Lipids / Q000096:biosynthesis*; D008079:Lipoproteins, VLDL / Q000378:metabolism*; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D009844:Oligosaccharides / Q000008:administration & dosage*; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014280:Triglycerides / Q000378:metabolism
D005227:Fatty Acids; D008055:Lipids; D008079:Lipoproteins, VLDL; D009844:Oligosaccharides; D010743:Phospholipids; D014280:Triglycerides; D005632:Fructose; D005992:Glycerol-3-Phosphate O-Acyltransferase