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.
Kok NN, Morgan LM, Williams CM, Roberfroid MB, Thissen JP, Delzenne NM
Unite de Biochimie Toxicologique et Cancerologique, Departement des Sciences Pharmaceutiques, Universite Catholique de Louvain, B-1200 Bruxelles, Belgium.
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.
PMID: 9649591, UI: 98315232