Evidence for an enhanced de novo synthesis of alkaline phosphatase in cholestatic rat liver using immunotitration and precursor incorporation techniques.

An antikidney phosphatase serum was produced. This showed a cross-reaction with liver phosphatase and precipitated the latter enzyme specifically in the double antibody method. An U-[14C] protein hydrolysate was injected intraperitoneally into rats, which had previously undergone bile duct ligation. Liver alkaline phosphatase was partially purified and immunoprecipitated. By determination of phosphatase labelling the extent of de novo synthesis of the phosphatase protein was evaluated. Comparing livers from control and cholestatic rats, it could be shown that 12 h after beginning of cholestasis the de novo synthesis of alkaline phosphatase was increased up to 4-fold and that is remained at a 2-fold increased level for at least 2 days.