The gastrointestinal tract and glucose tolerance.
OBJECTIVE
The development of incretin hormones and incretin analogues for the therapy of diabetes highlights the importance of the gastrointestinal tract in the maintenance of glucose tolerance.


RESULTS
The review focuses on recent information on the role of incretins and their breakdown products on insulin secretion, gastric emptying, and satiety. The importance of gastric emptying and its absorptive potential as well as of dietary composition on gastric emptying and glucose tolerance is highlighted. The concept of a portal glucose sensor in humans has been the subject of some controversy but has been recently revisited.


CONCLUSIONS
The gastrointestinal tract plays an important part in glucose tolerance. In this review we have examined how factors altering gastric emptying, insulin secretion in response to meal ingestion, and gastric emptying contribute to the maintenance and deterioration of glucose tolerance.
Vella
Adrian
A
Division of Endocrinology & Metabolism, Department of Medicine, Mayo Clinic & Foundation, 200 First ST SW, Rochester, MN 55905, USA. vella.adrian@mayo.edu
Camilleri
Michael
M
Rizza
Robert A
RA
D001786:Blood Glucose / Q000378:metabolism*; D003920:Diabetes Mellitus / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D004734:Energy Metabolism / Q000502:physiology; D005746:Gastric Emptying / Q000502:physiology; D005934:Glucagon / Q000378:metabolism; D052216:Glucagon-Like Peptide 1; D006706:Homeostasis; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D010446:Peptide Fragments / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism
D001786:Blood Glucose; D007328:Insulin; D010446:Peptide Fragments; D011498:Protein Precursors; D052216:Glucagon-Like Peptide 1; D005934:Glucagon