A comparison of histadine lactobionate solution with University of Wisconsin solution for rat liver and heart preservation

We developed a new solution mainly composed of Na-lactobionate and histidine (HL) and compared the effectiveness of this solution with that of University of Wisconsin (UW) solution using orthotopic liver and heterotopic heart transplantation in rats. The new solution has a higher sodium content and a lower potassium content (Na, 90 mEq/l; K, 45 mEq/l) than UW. Hydroxyethyl starch, adenosine, dexamethasone and insulin are not included. Buffering capacity is increased by adding histidine (90 mm/l) together with KH₂PO₄ (20 mm/l). Rat liver was perserved in either UW or HL solution hypothermically for 24 h and then transplanted orthotopically into the recipient rat. The heart was preserved in either solution for 18 h and transplanted heterotopically into the recipient rat. The 1-week survival rate for rats receiving livers preserved in UW for 24 h at 4°C was 29% (5/17). In contrast, the new solution (HL) gave a 78% (11/14) survival rate (P < 0.01). The 1-week heart graft survival rate, using UW solution was 50% (3/6), following 18-h cold preservation, whereas all hearts (7/7) continued to beat for over a week using new HL solution (P < 0.05). These results demonstrated that the new HL solution, with a substantial buffering capacity, was superior to UW solution in rat liver and heart preservation.