Cold storage of rat pancreas before purification of islet beta-cells

Allotransplantations in rats have demonstrated that aggregates of purified islet endocrine cells are less immunogenic than isolated islets. If purified islet cells are to be tested in humans, their preparation should be feasible from cold-preserved organs. We compared the yield in purified beta-cells from freshly harvested rat pancreases with that from cold-stored organs. After 24 h of preservation in Collins' solution or in University of Wisconsin (UW) solution, the number of purified beta-cells per pancreas was 40% lower (P less than 0.05) than that obtained from nonpreserved controls. Addition of 5 mM benzamidine/4% bovine serum albumin to Collins' solution resulted in similar recoveries as with freshly harvested organs; this addition did not increase the yield from UW solution-stored organs. When compared to preparations from fresh pancreases, islets and islet cells isolated from pancreases preserved in Collins' solution-bovine serum albumin-benzamidine were comparable in structural integrity, viability in culture, secretory responsiveness in vitro, and capability of correcting hyperglycemia in streptozocin-induced diabetic rats. We conclude that addition of benzamidine to Collins' preservation solution allows purification of islet beta-cells from 24-h-preserved rat pancreases in the same yield and quality as from freshly harvested organs. These results indicate that cold-preserved pancreases can be used for the preparation of purified islet cell grafts.