Aim of the study: The predominant injury during cold preservation of the liver appears to affect the non-parenchymal cells. Therefore we studied the contribution of hypoxia and the effect of the University of Wisconsin (UW) solution on the injury to cultured liver endothelial and Kupffer cells.
Methods: Cultured endothelial cells and Kupffer cells of the rat liver were incubated in Krebs-Henseleit buffer at 37 degrees C and in both, Krebs-Henseleit buffer and UW solution, at 4 degrees C. Hypoxic conditions were simulated by the addition of cyanide (1 mM), to some of the cultures glucose (10 mM) was added. Cell injury was assessed by the uptake of the vital dye trypan blue and by the release of cytosolic lactate dehydrogenase.
Results: Kupffer cells as well as endothelial cells exhibited a high hypoxia tolerance in Krebs-Henseleit buffer at both 37 degrees C and 4 degrees C. A large difference between both cell types, however, was seen during cold incubation in UW solution: whereas only 35 +/- 10% of Kupffer cells lost viability during 24 hrs under aerobic control conditions, the loss of viability of liver endothelial cells was already 83 +/- 12% under the same conditions. The addition of KCN increased the Kupffer cell injury to 75 +/- 8% but strongly decreased the endothelial cell injury to 3 +/- 2%. The addition of glucose to the cyanide-containing UW solution decreased the injury to Kupffer cells but increased the injury to endothelial cells.
Conclusion: During cold incubation in UW solution cultured liver endothelial cells are affected by an energy-dependent injury. This type of injury is not detectable in Kupffer cells.