Glutathione protects the rat liver against reperfusion injury after hypothermic preservation

Background & Aims: The extracellular generation of reactive oxygen species (ROS) by Kupffer cells contributes to reperfusion injury of the liver allograft. The endogenous antioxidant glutathione (GSH) can detoxify these ROS; however, this effect might be limited by the low extracellular concentration of GSH. We therefore investigated whether an increase of extracellular GSH protects the liver against reperfusion injury after Gold preservation. Methods: Livers of male Sprague-Dawley rats subjected to 24 hours of cold ischemia in University of Wisconsin solution (4 degrees C) were reperfused for 2 hours in the absence (controls) or presence of 0.5, 1, 2, or 4 mmol/L GSH (n = 4-6 each). Results: Two hours after starting reperfusion of control livers, the sinusoidal release of lactate dehydrogenase and purine nucleoside phosphorylase increased to 247 +/- 96 and 27 +/- 13 mU . min(-1) . g liver(-1), respectively, but only to 76 +/- 43 and 10 +/- 4 mU . min(-1) . g liver-l in the presence of 4 mmol/L GSH. This cytoprotective effect was confirmed histologically by a marked reduction of trypan blue staining of hepatocytes. Compared with control livers, postischemic bile now was significantly enhanced by GSH (0.15 +/- 0.02 vs. 0.41 +/- 0.11 mu L . min(-1) . g liver(-1)), indicating improved liver Function. During reperfusion of control livers, intracellular GSH content declined from 4.5 +/- 0.3 to 2.3 +/- 0.1 mu mol/g liver, but only to 3.8 +/- 0.4 mu mol/g liver in the presence of 4 mmol/L GSH. Reperfusion of untreated livers was accompanied by a prolonged increase of portal pressure to maximally 12.5 +/- 1.9 cm H2O, which was significantly attenuated by 4 mmol/L GSH (7.2 +/- 1.4 cm H2O). Similar cytoprotective and hemodynamic effects were observed with 2 mmol/L GSH, but not with 0.5 and 1 mmol/L GSH. Conclusions: Treatment of cold-preserved livers with GSH upon reperfusion prevents damage of:hepatocytes, deterioration of the hepatic circulation, and loss of intracellular GSM. In view of these protective effects and its low toxicity in humans, GSH should be considered a candidate drug for prevention of ROS-related reperfusion injury of the liver allograft.