Insulin, glucagon-like peptide 1, glucose-dependent insulinotropic polypeptide and insulin-like growth factor I as putative mediators of the hypolipidemic effect of oligofructose in rats.
The addition of oligofructose as a dietary fiber decreases the serum concentration and the hepatic release of VLDL-triglycerides in rats. Because glucose, insulin, insulin-like growth factor I (IGF-I) and gut peptides [i.e., glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1)]) are factors involved in the metabolic response to nutrients, this paper analyzes their putative role in the hypolipidemic effect of oligofructose. Male Wistar rats were fed a nonpurified diet with or without 10% oligofructose for 30 d. Glucose, insulin, IGF-I and GIP concentrations were measured in the serum of rats after eating. GIP and GLP-1 contents were also assayed in small intestine and cecal extracts, respectively. A glucose tolerance test was performed in food-deprived rats. Serum insulin level was significantly lower in oligofructose-fed rats both after eating and in the glucose tolerance test, whereas glycemia was lower only in the postprandial state. IGF-I serum level did not differ between groups. GIP concentration was significantly higher in the serum of oligofructose-fed rats. The GLP-1 cecal pool was also significantly higher. In this study, we have shown that cecal proliferation induced by oligofructose leads to an increase in GLP-1 concentration. This latter incretin could be involved in the maintenance of glycemia despite a lower insulinemia in the glucose tolerance test in oligofructose-fed rats. We discuss also the role of hormonal changes in the antilipogenic effect of oligofructose.
Kok
N N
NN
Unité de Biochimie Toxicologique et Cancérologique, Département des Sciences Pharmaceutiques, Université Catholique de Louvain, B-1200 Bruxelles, Belgium.
Morgan
L M
LM
Williams
C M
CM
Roberfroid
M B
MB
Thissen
J P
JP
Delzenne
N M
NM
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002432:Cecum / Q000378:metabolism; D004435:Eating; D005632:Fructose / Q000008:administration & dosage / Q000494:pharmacology*; D005749:Gastric Inhibitory Polypeptide / Q000097:blood* / Q000378:metabolism; D005934:Glucagon / Q000097:blood* / Q000378:metabolism; D052216:Glucagon-Like Peptide 1; D005951:Glucose Tolerance Test; D000960:Hypolipidemic Agents; D007328:Insulin / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007421:Intestine, Small / Q000378:metabolism; D008297:Male; D010446:Peptide Fragments / Q000097:blood* / Q000378:metabolism; D011498:Protein Precursors / Q000097:blood* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015430:Weight Gain
D001786:Blood Glucose; D000960:Hypolipidemic Agents; D007328:Insulin; D010446:Peptide Fragments; D011498:Protein Precursors; D005632:Fructose; D005749:Gastric Inhibitory Polypeptide; D007334:Insulin-Like Growth Factor I; D052216:Glucagon-Like Peptide 1; D005934:Glucagon