Investigations on the Mechanism of Induction of the Alkaline Phosphatase by Bromodesoxyuridine in Herpes simplex Virus Transformed Cells and the Transport of Uridine

Addition of BrdUrd in combination with prednisolone to HSVi-transformed hamster embryo cells induces an alkaline phosphatase (AP). FdUrd enhances, dThd reduces the inducing capacity of BrdUrd and prednisolone. Induction is prevented by addition of cycloheximide or of cytosine arabinoside. BrdUrd reduces transport and phosphorylation of exogenously applied labeled Urd, especially the amount of UTP, UDP and Urd-diphosphate sugars. The Lineweaver-Burk-plot of uridine-up­take after addition of BrdUrd reveales the characteristics of the mixed type inhibition (competi­tive-noncompetitive).