HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

High-fat feeding stimulates endocrine, glucose-dependent insulinotropic polypeptide (GIP)-expressing cell hyperplasia in the duodenum of Wistar rats.

AbstractAIMS/HYPOTHESIS:
Incretins are hormones released by enteroendocrine cells in response to meals, depending upon absorption of nutrients. The present study aimed to elucidate the mechanisms through which a high-fat diet (HFD) induces insulin resistance and insulin hypersecretion by focusing on the effects on enteroendocrine cells, especially those secreting glucose-dependent insulinotropic polypeptide (GIP).
METHODS:
Forty male Wistar rats, 4 months old, were randomised into two groups; one group received a chow diet and the other one received a purified tripalmitin-based HFD ad libitum. An OGTT was performed every 10 days and histological and immunofluorescence evaluations of the duodenum were obtained at 60 days from the beginning of the diets. Plasma glucose, insulin, GIP and glucagon-like peptide-1 (GLP-1) levels were measured. Immunofluorescence analysis of duodenal sections for pancreatic duodenal homeobox-1 (PDX-1), KI67, GLP-1, GIP and insulin were performed.
RESULTS:
Compared with chow diet, HFD induced a progressive significant increase of the glucose, insulin and GIP responses to OGTT, whereas GLP-1 circulating levels were reduced over time. After 60 days of HFD, cellular agglomerates of KI67 and PDX-1 positive cells, negative for insulin and GLP-1 but positive for GIP staining, were found inside the duodenal mucosa, and apoptosis was significantly increased.
CONCLUSIONS/INTERPRETATION:
With the limitation that we could not establish a causal relationship between events, our study shows that HFD stimulates duodenal proliferation of endocrine cells differentiating towards K cells and oversecreting GIP. The progressive increment of GIP levels might represent the stimulus for insulin hypersecretion and insulin resistance.
AuthorsD Gniuli, A Calcagno, L Dalla Libera, R Calvani, L Leccesi, M E Caristo, R Vettor, M Castagneto, G Ghirlanda, G Mingrone
JournalDiabetologia (Diabetologia) Vol. 53 Issue 10 Pg. 2233-40 (Oct 2010) ISSN: 1432-0428 [Electronic] Germany
PMID20585935 (Publication Type: Journal Article)
Chemical References
  • Blood Glucose
  • Dietary Fats
  • Insulin
  • Gastric Inhibitory Polypeptide
  • Glucagon-Like Peptide 1
Topics
  • Analysis of Variance
  • Animals
  • Area Under Curve
  • Blood Glucose (metabolism)
  • Body Weight
  • Dietary Fats (metabolism)
  • Duodenum (metabolism, pathology)
  • Enteroendocrine Cells (metabolism, pathology)
  • Enzyme-Linked Immunosorbent Assay
  • Fluorescent Antibody Technique
  • Gastric Inhibitory Polypeptide (metabolism)
  • Glucagon-Like Peptide 1 (blood)
  • Glucose Tolerance Test
  • Hyperplasia (metabolism)
  • In Situ Nick-End Labeling
  • Insulin (blood)
  • Intestinal Mucosa (metabolism, pathology)
  • Male
  • Random Allocation
  • Rats
  • Rats, Wistar

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: