Reperfusion injury is dramatically increased by gentle liver manipulation during harvest

Kupffer cell-dependent injury in livers gently manipulated during harvest develops upon reperfusion. The purpose of this study was to characterize this injury and to detect underlying mechanisms. Livers from female Sprague-Dawley rats were harvested for transplantation within 25 min. Minimal dissection was performed during the first 12 min, including freeing the liver from ligaments. After this, for further 13 min, livers were either left alone or manipulated gently. The livers were then cold-stored for 24 h in University of Wisconsin (UW) solution and perfused with oxygen-saturated Krebs-Henseleit buffer at 37 degrees C. Trypan blue in the buffer was used to index microcirculation. Cell damage was assessed with histology. Initial dissection during harvest and cold storage had minimal effects on sinusoidal lining cells; in contrast, the subsequent gentle organ manipulation dramatically increased cell death 6.5-fold, while the time for complete trypan blue distribution increased 2.3-fold (P < 0.05). Manipulation increased proteolysis 2-fold (P < 0.05). At harvest, manipulation increased portal venous pressure significantly by 68%. Treatment of donors with gadolinium chloride, a selective Kupffer cell toxicant, or with dietary glycine, an inhibitor of Kupffer cell activation, prevented effects of organ manipulation on all parameters studied. These findings demonstrate Kupffer cell-dependent reperfusion injury of sinusoidal lining cells caused by manipulation of the liver during its recovery. The mechanisms are those of proteolysis and impaired hepatic microcirculation.