A COMPARISON OF 4 SOLUTIONS FOR COLD-STORAGE OF PANCREATIC-ISLETS

Clinical pancreatic islet transplantation requires cold storage of isl ets for some hours. The best solution for cold storage will be that wh ich maintains islet viability for the longest time. We have examined t he viability of rat and human islets after storage at 4 degrees C for up to 6 days in Hanks' balanced salt solution, University of Wisconsin solution (UW), and 2 modified versions of this last solution, Sumimot o D (SD) and histidine-lactobionate (HL). The integrity of cold-stored rat and human islets of Langerhans has been examined using supravital stains and electron microscopy. In addition, the viability of cold-st ored rat islets was tested by intraportal transplantation into syngene ic streptozotoein-induced diabetic recipients. The in vitro studies sh owed good preservation of islets stored in UW, SD, and HL for up to 72 hr. In comparison, storage for periods as short as 24 hr in HBSS mark edly reduced islet integrity. The transplantation studies showed that rat islets cold stored in HBSS solution for 24 hr were not able to rev erse experimental diabetes, whereas those stored in the other 3 soluti ons for 24 hr successfully reversed diabetes within 1 week of transpla ntation. After 48-hr cold storage, only islets preserved in HL solutio n were uniformly capable of producing functioning islet grafts. None o f the tested solutions was able to maintain islet viability sufficient ly to allow successful transplantation after more than 48 hr of cold s torage. These experiments demonstrate that good islet viability is mai ntained for up to 24 hr of storage in UW, SD, and HL, and even after 4 8-hr cold storage in HL solution, whereas preservation in HBSS solutio n was deleterious to islet viability within 24 hr.