Patterns of serum alkaline phosphatase activity in unilateral hepatic duct obstruction: a clinical and experimental...

The levels of serum alkaline phosphatase (ALP) were measured in eight patients with bile duct obstruction limited to one lobe of the liver. Although an initial rise of enzyme concentration was documented in every patient, unrelieved biliary obstruction was associated with a gradual return of ALP to normal values. The return to normal levels coincided with the development of atrophy of that part of the liver deprived of its bile drainage. An animal model of experimental selective biliary obstruction supported a causative association between reduction of hepatocyte mass and a decrease in ALP activity. It appears that normal serum ALP levels can be expected with advanced obstructive biliary disease. Suspected lobar or segmental duct obstruction warrants investigation--even if liver function tests are normal.