Pancreatic Islet Isolation After Gastric Bypass in a Rat Model: Technique and Initial Results for a Promising Research Tool

Surg Obes Relat Dis. Sep-Oct 2010;6(5):532-7. doi: 10.1016/j.soard.2010.05.018. Epub 2010 Jun 10.

Abstract

Background: Roux-en-Y gastric bypass (RYGB) affords a high remission rate of type 2 diabetes mellitus among morbidly obese diabetic patients. We report the use of the isolated islet technique to assess pancreatic function and glucoregulatory mechanisms after RYGB surgery.

Methods: A total of 15 adult, male, Sprague Dawley diet-induced obese rats were randomly divided into 3 experimental groups: sham, RYGB, and pair-fed, with 5 rats in each group. The body weight was measured at baseline and every week for 4 weeks. Pancreatic islet function was assessed in vitro according to the amount of insulin secreted from isolated islets incubated in 2 mM and 20 mM glucose for 1 hour at 37 °C. Fasting plasma glucose, insulin, glucagon-like peptide-1, PYY3-36, and glucose-dependent insulinotropic peptide were measured at baseline and 28 days after surgery.

Results: The baseline body weight was 917 ± 61, 831 ± 42, and 927 ± 43 g for the sham, RYGB, and pair-fed groups, respectively. The RYGB group lost 32% body weight compared with 16% for the sham and 24% for the pair-fed groups. Glucose-stimulated insulin secretion from the isolated islets in the RYGB group was greater than in the comparison groups (P = .04) at 4 weeks after surgery. Fasting plasma glucagon-like peptide-1 and PYY3-36 were significantly increased at 4 weeks in the RYGB group.

Conclusion: Islet isolation and stimulation in the present animal model was feasible, affords a direct measurement of pancreatic islet function, and might provide a useful tool to study the effects of RYGB on pancreatic function and the relationship between islet cell function and incretin production after bariatric surgery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Blood Glucose / analysis
  • Gastric Bypass / methods*
  • Gastric Inhibitory Polypeptide / blood
  • Glucagon-Like Peptide 1 / blood
  • Hyperglycemia / surgery
  • Insulin Resistance
  • Islets of Langerhans / surgery*
  • Male
  • Models, Animal
  • Obesity / surgery
  • Peptide Fragments
  • Peptide YY / blood
  • Random Allocation
  • Rats
  • Rats, Sprague-Dawley

Substances

  • Blood Glucose
  • Peptide Fragments
  • Peptide YY
  • peptide YY (3-36)
  • Gastric Inhibitory Polypeptide
  • Glucagon-Like Peptide 1