Abstract
Auxiliary liver allografts were inserted into baboons and allowed to undergo rejection. The incorporation of (14)C leucine into alkaline phosphatase was measured in both host and donor livers with the aid of an anti-alkaline phosphatase antibody. The results indicate that the increased serum alkaline phosphatase levels found under these circumstances are due to increased synthesis of the enzyme by both livers. Furthermore, it was shown that in the absence of biliary obstruction, this enhanced production of alkaline phosphatase is accompanied by an increase in the excretion of the enzyme into bile. It is suggested that the stimulus for the enhanced production of alkaline phosphatase is a substance which is normally produced in the liver and excreted into the bile.