Faculty Collaboration Database

Differential responses of the incretin hormones GIP and GLP-1 to increasing doses of dietary carbohydrate but not dietary protein in lean rats. Am J Physiol Gastrointest Liver Physiol 2010 Aug;299(2):G476-85

Date

06/05/2010

Pubmed ID

20522638

Pubmed Central ID

PMC2928540

DOI

10.1152/ajpgi.00432.2009

Scopus ID

2-s2.0-77955640923 (requires institutional sign-in at Scopus site)   36 Citations

Abstract

Previous studies have shown that oral ingestion of nutrients stimulates secretion of the incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1); however, it is unclear whether there is a dose-dependent response between the amount of nutrient ingested and the secretion of the hormones in vivo. Using our lymph fistula rat model, we previously demonstrated that both GIP and GLP-1 responded dose dependently to increasing amounts of infused dietary lipid and that the GLP-1-secreting cells were more sensitive to changes in intestinal lipid content. In the present study, we investigated the dose-dependent relationships between incretin secretion and the two remaining macronutrients, carbohydrate and protein. To accomplish this objective, the major mesenteric lymphatic duct of male Sprague-Dawley rats was cannulated. Each animal received a single bolus (3 ml) of saline, dextrin, whey protein, or casein hydrolysate (0.275, 0.55, 1.1, 2.2, 4.4 kcal) via a surgically inserted duodenal or ileal feeding tube. Lymph was continuously collected for 3 h and analyzed for GIP and GLP-1 content. Both GIP and GLP-1 outputs responded dose dependently to increasing amounts of dietary carbohydrate but not protein. Additionally, we found that the GIP-secreting cells were more sensitive than the GLP-1-secreting cells to changes in intestinal carbohydrate content.

Author List

Yoder SM, Yang Q, Kindel TL, Tso P

Author

Tammy Lyn Kindel MD, PhD Professor in the Surgery department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Caseins
Dextrins
Dietary Carbohydrates
Dietary Proteins
Dose-Response Relationship, Drug
Enteral Nutrition
Gastric Inhibitory Polypeptide
Glucagon-Like Peptide 1
Ileum
Incretins
Lymph
Male
Mesentery
Milk Proteins
Rats
Rats, Sprague-Dawley
Thinness
Whey Proteins