Examination of the role of the impermeants lactobionate and raffinose in a modified UW solution.

Rat liver transplants were performed in order to assess the importance of the impermeant anion lactobionate and the trisaccharide raffinose on the effectiveness of a simplified variant of UW solution for liver preservation by simple cold storage. Rat livers were stored at 4 degrees C for 18, 24, 30, or 40 hr in a modified UW solution or in one of three variants of UW in which one of these impermeants was replaced by another more permeable agent. Using modified UW solution (solution A), 50% (5/10) of rats receiving livers that had been preserved for 30 hr survived for more than 1 week; with solution B, which differs from A in the replacement of raffinose by glucose, the 1-week survival was 60% (6/10) after 30-hr preservation. Solution C, which is identical to A except for the replacement of lactobionate by gluconate, gave 20% (2/10) survival rate after 30-hr preservation. However, using solution D, which is identical to A except for substitution of chloride for lactobionate, none (0/8) of the rats receiving liver preserved for 30 hr survived. These results suggest that the inclusion of lactobionate as a major anion plays a crucial role in the effectiveness of UW solution, whereas raffinose can be replaced by more permeant glucose without deleterious effect.