[Biochemical characterization of a high-molecular weight alkaline phosphatase in a patient with cholangiocarcinoma (alpha-1 alkaline phosphatase)].

The authors analysed the alkaline phosphatases present in the serum of a patient with cholangiocarcinoma. The electrophoretic analysis on cellulose acetate revealed two bands of AP activity in positions alpha 1 and alpha 2. The more anodic of the isoenzymes of AP presented most of the features of the high molecular weight isoenzyme found in human bile, except that it was non-competitively inhibited by L-homoarginine. This feature, which distinguishes this isoenzyme form the biliary isoenzyme of AP, indicates the existence of another type of high molecular weight isoenzyme present in malignant hepatic diseases.