COLD-PRESERVATION AND CRYOPRESERVATION OF DOG LIVER AND KIDNEY SLICES

The use of tissue slices in culture could decrease the number of anima ls used in health-related research and decrease experimental variation . This reduction may come about particularly if the methods of cold- a nd cryopreserving tissue slices are perfected, and one can conduct seq uential in vitro experiments into xenobiotic metabolism, organ-specifi c toxicity, or organ-specific biochemical processes with tissue slices . With this goal in mind, dog Liver and kidney slices were placed in c old storage at 0 degrees C using Viaspan (UW), Euro-Collins (EC), Sack s + prostacyclin (SP), and V-7 (V7) cold-preservation solutions for 10 days. Viability was assessed each day by measuring K+ content and pro tein synthesis after 4 h of incubation in Waymouth + 10% fetal calf se rum (FCS). Dog liver slices can be cold-preserved in V7 for up to 7 da ys using K+ retention as the viability criterion but only up to 4 days using protein synthesis. Dog kidney slices can be cold-preserved in U W, EC, and V7 for up to 10 days using K+ retention, but only V7 could maintain protein synthesis for 10 days. Cryopreserved dog liver and ki dney slices retained 63-68% of control viability after 4 h of incubati on in FCS. The cryopreservation regimen included using 10% dimethyl su lfoxide in FCS as the cryoprotectant: a freezing rate of 0.5 degrees C /min for liver slices and 12 degrees C/min for kidney slices, and thaw ing in 37 degrees C FCS. Continued development of cold- and cryopreser ving tissue slices could reduce the numbers of animals used and provid e accurate and reproducible data. (C) 1996 Academic Press, Inc.