Ethanol Self-Administration and Alterations in the Liv the Cynomolgus Monkey, Macaca fascicularis Priscilla Ivester, L. Jackson Roberts, II, Tracey Young, Diana Stafforini, Jeffrey Vivian, Cynthia Lees, Jennifer Young, James Daunais, David Friedman, Richard A. Rippe, Christopher J. Parsons, Kathleen A. Grant, and Carol Cunningham Background: Most of the studies of alcoholic liver disease use models in which animals undergo involuntary administration of high amounts of ethanol and consume diets that are often high in polyunsaturated fatty acids. The objectives of this study were (1) to evaluate whether cynomolgus monkeys (Macaca fascicularis) drinking ethanol voluntarily and consuming a diet with moderate amounts of lipid would demonstrate any indices of alcoholic liver disease past the fatty liver stage and (2) to determine whether these alterations were accompanied by oxidative stress. Methods:Six adult male and 6 adult female cynomolgus monkeys were allowed to consume eth- anol voluntarily for 18 to 19 months. Additional monkeys were maintained on the same consumption protocol, but were not provided with ethanol. During the course of the study, liver biopsy samples were monitored for lipid deposition and inflammation, serum for levels of liver enzymes, and urine for concentrations of the isoprostane (IsoP) metabolite, 2,3-dinor-5,6-dihydro-15-F 2t -IsoP, a biomarker for oxidative stress. Liver mitochondria were monitored for respiratory control and liver for concentrations of neutral lipids, adenine nucleotides, esterified F 2 isoprostanes, oxidized proteins, 4- hydroxynonenal (HNE)-protein adducts, and protein levels of cytochrome P-450 2E1 and 3A4. Results:Ethanol consumption ranged from 0.9 to 4.05 g/kg/d over the period of the study. Serum levels of aspartate amino transferase were elevated in heavy-consuming animals compared with those in ethanol-naı ¨ve or moderate drinkers. Many of the ethanol consumers developed fatty liver and most showed lociof inflammation. Both hepatic energy charge and phosphorylation potential were decreased and NADH-linked respiration waslightly, but significantly depressed in coupled mitochondria as a result of heavy ethanol consumption. The urinary concentrations of 2,3-dinor- 5,6-dihydro-15-F 2t -IsoP increased as high as 33-fold over that observed in ethanol-abstinent animals. Liver cytochrome P-450 2E1 concentrations increased in ethanol consumers, but there were no ethanol-elicited increases in hepaticconcentrationsof the esterified F 2 isoprostanes, oxidized proteins, or HNE-protein adducts. Conclusion: Our studies show that cynomolgus monkeys undergoing voluntary ethanol consump- tion for 1.5 years exhibit many of the features observed in the early stages of human alcoholic liver disease. Ethanol-elicited fatty liver, inflammation, and elevated serum aspartate amino transferase were evident with a diet that contained modest amounts of polyunsaturated lipids. The dramatic increases in urinary IsoP demonstrated that the animals were being subjected to significant oxidative stress that correlated with their level of ethanol consumption. Key Words:Cynomolgus Monkeys, Alcoholic Liver Disease, Isoprostanes, Ethanol Self-Admin- istration. T HE NONHUMAN PRIMATE has been utilized previously as a model for studies of alcoholic liver disease, most notably by Lieber and DeCarli (1994), who have employed baboons maintained on an ethanol-con- taining liquid diet. Other primate models used include th macaque species, Macaca nemestrina (Cunningham et a 1981;Leatherset al., 1981),Macaca radiata (French et al., 1983; Mezey et al., 1983), Macaca fascicularis (Cu ningham etal.,1983;Ivester etal., 2003),and Macaca mulatta (Bautista et al., 2001; Pawlosky and Salem, 200 Fibrosis and/or cirrhosis have been observedafter baboonswere maintained forextended periods on a nutritionallyadequateliquid diet containing50% of calories as ethanol (Popper and Lieber, 1980).Fibrosis also occurredin Macaca mulatta(rhesus monkeys), From the Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina (PI, TY, CC); the Depart- ment of Physiology, Wake Forest University School of Medicine, Win- ston-Salem, North Carolina (JV, JY, JD, DF, KG); the Section of Comparative Medicine, Wake Forest University School of Medicine, Win- ston-Salem, North Carolina (CL); the Departments of Pharmacology and Medicine, Vanderbilt University, Nashville, Tennessee (LJR); the Hunts- man Cancer Institute, University of Utah, Salt Lake City, Utah (DS); and the Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina (RAR, CJP). Received for publication September 1, 2005; accepted September 19, 2006. This work was supported by NIH grants AA11997, AA13610, AA13641, AA02887, AA00279, GM42056, GM15431, and DK26657 Reprint requests: Carol Cunningham, PhD, Department of Biochem- istry, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1016; Fax: 336-716-7671; E-mail: cunn@wfubmc.edu Copyright r 2006 by the Research Society on Alcoholism. DOI: 10.1111/j.1530-0277.2006.00276.x Alcohol Clin Exp Res, Vol 31, No 1, 2007: pp 144–155 144 ALCOHOLISM : CLINICAL AND EXPERIMENTAL RESEARCH Vol. 31, No. 1 January 2007