Glucose-dependent insulinotropic polypeptide and its role in obesity.
OBJECTIVE
As we strive to improve our understanding of the factors that contribute to the pathogenesis of obesity, it is certainly logical to speculate that a nutrition-dependent component emanating from the gastrointestinal tract, which has the capacity to regulate insulin expression, could represent an etiologic factor in this serious health issue. One such regulatory peptide that possesses these properties is glucose-dependent insulinotropic polypeptide. Release of this peptide is stimulated by the ingestion of glucose and fat from the upper portion of the small intestine, which in turn enhances the release of insulin from the pancreas.


RESULTS
In addition to its indirect effects in inducing obesity through the stimulation of insulin, a potent efficiency hormone, glucose-dependent insulinotropic polypeptide, like insulin, also directly modulates a variety of factors that are important in adipocyte homeostasis. Such factors include lipoprotein lipase, Akt, and GLUT-4, all of which promote the storage of fat.


CONCLUSIONS
In this review, various mechanisms by which glucose-dependent insulinotropic polypeptide may serve as a link that indirectly and directly contributes to the development of obesity will be discussed. Understanding the peptide's role will potentially help provide novel ways to prevent and treat obesity.
Song
Diane H
DH
Boston University School of Medicine, Boston Medical Center, Boston, Massachusetts 02118, USA.
Wolfe
M Michael
MM
D017667:Adipocytes / Q000378:metabolism; D000818:Animals; D005749:Gastric Inhibitory Polypeptide / Q000378:metabolism*; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D050356:Lipid Metabolism; D008071:Lipoprotein Lipase / Q000378:metabolism; D009765:Obesity / Q000209:etiology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism
D051275:Glucose Transporter Type 4; D007328:Insulin; D005749:Gastric Inhibitory Polypeptide; D051057:Proto-Oncogene Proteins c-akt; D008071:Lipoprotein Lipase