Background: The injury resulting from cold preservation/reperfusion primarily affects sinusoidal endothelial cells, while hepatocytes are thought to be less vulnerable; morphological changes and increased cytokine release suggest that Kupffer cells are activated. We evaluated the extent of functional damage to the different cell types in the liver after cold preservation and transplantation. Additionally, we analyzed in vivo the patterns of functional recovery of all three cell types over the first week after transplantation in Lewis rats.
Methods: We evaluated the in vivo uptake of hyaluronic acid, indocyanine green, and radio-labeled sulphur colloid to assess the function of sinusoidal endothelial cells, hepatocytes, and Kupffer cells, respectively. Measurements were performed immediately after transplantation using syngeneic grafts preserved in University of Wisconsin solution for different periods. Functional recovery was monitored in animals receiving grafts preserved for 24 hr over the first postoperative week.
Results: We found that hepatocyte were less affected compared with the profoundly damaged endothelial cells. The phagocytic ability of Kupffer cells was, however, also seriously compromised, which suggests a selective down-regulation. Functional recovery occurs in a differential manner during the first postoperative week starting with hepatocytes followed by sinusoidal endothelial cells. Phagocytic function further deteriorates after transplantation before showing improvement.
Conclusions: In viable liver grafts, all cell types recover from preservation/reperfusion injury by the end of the first week after transplantation. The differential time courses of the recovery suggest that successful sinusoidal endothelial cell recovery may depend upon prior hepatocyte regeneration and may involve a paracrine interaction, via cytokines and growth factors.