P103

Comparison study on functionality of pancreatic islets transplanted in the liver or under the kidney capsule of diabetic mice

Daria Zorzi, Tammy Phan, Boyd Carr, Luca Cicalese, Cristiana Rastellini

Deaprtment of Surgery, Texas Transplant Center, University of Texas Medical Branch, Galveston, TX, United States

Background: In the clinical setting, the liver is the site currently used for pancreatic islet transplant (ITX). Although results have improved overtime due to better immunosuppression and isolation techniques, the liver as implantation site may represent a limiting factor. The aim of this study is to investigate islet functionality at different post-operative time points when transplanted in the liver

or kidney as compared to native islets in control animals.

Material and Methods: Pancreatic islets where isolated from 9-12 weeks old C57BL10 male mice and transplanted in syngeneic streptozotocin induced diabetic animals (1,000islets/recipient). Study groups included: A (n= 4) intra portal and, B (n=4) under the kidney capsule ITX. Both groups were compared to control animals (n=9). Blood glucose levels and body weight (BW) were monitored. Intra peritoneal glucose tolerance tests (IPGTT) were performed at 1, 3 and 6 months post ITX. Glucose response at different IPGTT time points where compared and p value was calculated to determine significant differences.

Results: All animals included reversed diabetes within 1 week post ITX and no significant differences were observed in glycemic control and BW during the study period. However, when IPGTT were compared, the islets transplanted in the liver had a significant worse performance for all post ITX follow-up periods. One and 6 months post ITX mean IPGTT curves are shown in the figure (* p<0.05).

Conclusions: These data demonstrate that pancreatic islets transplanted in the liver have an early and late post ITX impaired response to glucose challenges suggesting that the liver might not be the ideal site for ITX.