The central opioid system in liver disease and its complications

The best known example of an interaction between the liver and the brain is hepatic encephalopathy. In the 90s a central nervous system origin of the pruritus of cholestatic liver disease and more recently of fatigue of liver disease has been suggested. Hence, three important manifestations of liver disease may be of central origin. Evidence is accumulating that the central opioid system is involved in the development of these manifestations. This short review summarizes current knowledge on the role of the opioid system in development of these liver disease manifestations.