The relationship between plasma free fatty acids and experimentally induced hepatic encephalopathy in the rat

Two experimental models of hepatic encephalopathy in the rat have been investigated in order to study the postulated relationship between plasma free fatty acids concentration (C6 - C22:0) and the degree of hepatic encephalopathy. As a model of chronic hepatic encephalopathy, porta caval shunted rats were studied for 15 weeks, whereas rats with acute liver ischemia were used as a model for acute hepatic encephalopathy. In porta caval shunted rats only a minor degree of hepatic encephalopathy developed, whereas plasma ammonia concentration increased significantly (82 +/- 8 to +/- 440 +/- 32 mumol/l). Acute liver ischemia induced severe grades of hepatic encephalopathy associated with high levels of plasma ammonia (+/- 1 200 mumol/l). Since no significant changes in plasma free fatty acids were observed during both chronic and acute hepatic encephalopathy no correlation between plasma free fatty acids and the stage of hepatic encephalopathy was found. Our data do not support an important role of free fatty acids in the pathogenesis of acute or chronic hepatic encephalopathy in the rat.