[Physiology of bile formation (author's transl)].

Generation of bile flow in humans depends mainly on two transport mechanisms of the hepatocyte. One of these is responsible for secretion of bile acids, the other for transport of sodium into the bile canaliculi. Accordingly, a bile acid dependent fraction of hepatocytic bile can be distinguished from a bile acid independent fraction. Many endogenous and exogenous substances, including x-ray contrast media, are secreted into hepatocytic bile by more or less specific transport systems. The bile produced by the liver cells is then modified by admixture of ductular bile and by reabsorptive processes in the biliary passages and in the gallbladder. Increased knowledge about these mechanisms represents one of the requirements for progress in oral and intravenous cholangiography.