Mechanism of action of antiviral hetarylhydrazones in vitro.

Three antiviral hetarylhydrazones showed a depression of 3H-uridine incorporation into RNA of FL cells as a consequence of inhibition of uridine transport into the cells. By eliminating the action of the compounds on transport processes with the prelabelling method, only one compound showed a nearly 50% reduction of cellular RNA synthesis during the whole incubation period, whereas the other two compounds had no influence during the first 6 hr. Under prelabelling conditions all three compounds completely inhibited the synthesis of Mengo virus RNA. One compound did not affect cellular DNA synthesis, but presumably depressed thymidine transport into the cells.