This volume contains the papers presented at the International Symposium on "Cirrhosis, Hyperammonemia and Hepatic Encephalopathy", held in Valencia, Spain, January 24th-27th, 1994. Liver cirrhosis and other hepatic dysfunctions such as fulminant hepatic failure and congenital defects of urea cycle enzymes can lead to hepatic encephalopathy, coma and death. Hepatic encephalopathy is one of the main causes of death in western countries. The ability to detoxify ammonia by its incorporation into urea is diminished by impaired liver function, resulting in increased ammonia levels in blood and brain. Hyperammonemia is considered one of the main factors in the mediation of hepatic encephalopathy and the classical clinical treatments are directed towards reducing blood ammonia levels. However, the molecular bases of the pathogenesis of hepatic encephalopathy and the role of hyperammonemia in this process remain unclear and several hypotheses have been proposed. To clarify the mechanisms involved in hepatic encephalopathy and hyperammonemia suitable animal models are necessary. The animal models available and the ideal features of an animal model are presented in the initial part of the book.