HEPATIC MICROSOMAL MIXED-FUNCTION OXIDASE SYSTEM RESPONSE TO SELECTIVE BILIARY OBSTRUCTION

Three days after selective biliary obstruction in rats, bile output from the single unobstructed lobe was equivalent to the usual output from 3 hepatic lobes. There was a significant decrease in the level of the hepatic microsomal mixed function oxidase system components, cytochrome P-450 and NADPH-cytochrome c reductase. The levels observed after 3 days were reduced to an equivalent extent in both selectively obstructed and unobstructed lobes, and corresponded to the level seen after total biliary obstruction. Hepatic bromosulphothalein Tm was significantly reduced 3 days after selective obstruction, but did not differ from normal after 6 days. A factor generated in response to biliary obstruction acts to lower hepatic mixed function oxidase system components and increase bile flow in functioning hepatic tissue.