Predicting the success of pancreatic islet isolation : a study of pancreatic preservation and islet cell apoptosis

Critical to successful islet transplantation is the procurement of a high quality donor pancreas, maintenance of islet viability during pancreatic preservation and isolation of a high yield of viable and functioning islets. However, islet isolation exposes cells to considerable enzymatic and mechnical stressors resulting in the loss of tissue architecture, and such an environment can result in cell death by apoptosis and necrosis. To date it has not been possible to reliably predict the success of subsequent islet isolation by testing the donor pancreas, and many pancreata complete the time consuming and costly process only to result in a poor islet yield. It would be a significant clinical and financial advantage to be able to assess the suitability of the donor pancreas prior to islet isolation.;This thesis used a novel method of assessing donor pancreatic adenosine nucleotide concentrations throughout the isolation process and correlated these to conventional measures of islet yield, viability, function and pancreatic apoptosis. Pre-clinical rodent and porcine models were used to determine the effect of conventional and modified methods of pancreatic preservation using various preservation solutions. Finally an assessment of a small number of human donor pancreata was made using the new technique prior to clinical islet isolation.;The ADP:ATP ratio provided a means of predicting islet yield in both rodent and porcine models after pancreas preservation. Additionally, the ratio predicted islet purity and in vitro function of rodent islets. It provides a rapid means of assessing tissue viability during pancreas preservation and may provide the likelihood of subsequent successful islet isolation.