Vol. 290, Issue 2, 611-620, August 1999

Binge Drinking Disturbs Hepatic Microcirculation after Transplantation: Prevention with Free Radical Scavengers¹

Zhi Zhong, Gavin E. Arteel , Henry D. Connor, Peter Schemmer, Shu-Chuan Chou, James A. Raleigh , Ronald P. Mason, John J. Lemasters and Ronald G. Thurman

Department of Pharmacology (Z.Z., G.E.A., H.D.C., P.S., R.G.T.), Curriculum in Toxicology (G.E.A., J.A.R., R.G.T.), Department of Radiation Oncology (S.-C.C., J.A.R.), and Department of Cell Biology and Anatomy (J.J.L.), University of North Carolina at Chapel Hill, Chapel Hill; and Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences (R.P.M.), Research Triangle Park, North Carolina

Disturbances in hepatic microcirculation increase graft injury and failure; therefore, this study evaluates the effects of ethanol on microcirculation after liver transplantation. Donor rats were given one dose of ethanol (5 g/kg) by gavage 20 h before explantation, and grafts were stored in University of Wisconsin solution for 24 h before implantation. Acute ethanol treatment decreased 7-day survival of grafts from about 90 to 30%, increased transaminase release nearly 4-fold, and decreased bile production by 60%. Moreover, portal pressure increased significantly and liver surface oxygen tension decreased about 50%, indicating that ethanol disturbs hepatic microcirculation. Pimonidazole, a 2-nitroimidazole hypoxia marker, was given i.v. to recipients 30 min after implantation, and grafts were harvested 1 h later. Ethanol increased hepatic pimonidazole binding about 3-fold, indicating that ethanol led to hypoxia in fatty grafts. Ethanol also significantly increased free radicals in bile. Catechin (30 mg/kg i.v. upon reperfusion), a free radical scavenger, and Carolina Rinse solution, which contains several agents that inhibit free radical formation, minimized disturbances in microcirculation and prevented pimonidazole adduct formation significantly. These treatments also blunted increases in transaminase release and improved survival of fatty grafts. Destruction of Kupffer cells with GdCl₃ (20 mg/kg i.v. 24 h before explantation) or inhibition of formation of leukotrienes with MK-886 (50 µM in University of Wisconsin or rinse solution) also minimized hypoxia and improved survival after transplantation. Taken together, these results demonstrate that ethanol disturbs hepatic microcirculation, leading to graft hypoxia after transplantation, most likely by activating Kupffer cells and increasing free radical production.