Clinical aspects of bile acid metabolism in liver diseases

For a long time, it has been assumed that the liver plays an important role in the formation and excretion of bile acids and that the metabolism of bile acids, therefore, can be disturbed to some extent in liver diseases. Pathophysiological aspects of the disturbed metabolism of bile acids remained obscure at the time when procedures of qualitative and quantitative analyses, identification and estimation of bile acids began to be utilized in practice 20 years ago. Since then, the metabolism of bile acids has been clarified in individuals under normal as well as pathological circumstances. Because of a functionally and morphological close relation between hepatic epithelial cells and the metabolism of bile acids, the pathophysiological aspects of the disturbed metabolism of bile acids in parenchymatous inflammatory diseases of the liver, fatty liver, cholestasis and primary hepatocellular carcinoma are attracting considerable attention. First applied to the measurement of human bile acids in blood plasma in 1965, gas-liquid chromatography has been utilized as a standard method in medical practice. Recently, radioimmunoassay and enzyme linked radioimmunoassay have been utilized. This progress in the estimation of bile acids has awoken our interest in the pathophysiological significance of bile acids in liver diseases. The author reviewed the information on bile acid metabolism in liver diseases which has been reported up to the present.