Pancreatic islet isolation after gastric bypass in a rat model: technique and initial results for a promising research tool.
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.


CONCLUSIONS
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.
Gatmaitan
Patrick
P
Bariatric and Metabolic Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA.
Huang
Hazel
H
Talarico
Joseph
J
Moustarah
Fady
F
Kashyap
Sangeeta
S
Kirwan
John P
JP
Schauer
Philip R
PR
Brethauer
Stacy A
SA
D000704:Analysis of Variance; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D015390:Gastric Bypass / Q000379:methods*; D005749:Gastric Inhibitory Polypeptide / Q000097:blood; D052216:Glucagon-Like Peptide 1 / Q000097:blood; D006943:Hyperglycemia / Q000601:surgery; D007333:Insulin Resistance; D007515:Islets of Langerhans / Q000601:surgery*; D008297:Male; D023421:Models, Animal; D009765:Obesity / Q000601:surgery; D010446:Peptide Fragments; D019894:Peptide YY / Q000097:blood; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley
D001786:Blood Glucose; D010446:Peptide Fragments; D019894:Peptide YY; C061785:peptide YY (3-36); D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1