3-Deazauridine: inhibition of ribonucleic acid virus-induced cytopathogenic effects in vitro.

3-Deazauridine, a synthetic analogue of uridine and a potential antitumor agent, was found to possess antiviral activity against a number of ribonucleic acid-containing animal viruses in mammalian cell culture. Inhibition of virus-induced cytopathogenic effects by 3-deazauridine was observed in cells infected with rhinovirus types 1A and 13, coxsackievirus type A21, and PR-8 influenza virus, but not in cells infected with poliovirus type 2 or echovirus type 12. The extracellular yield of progeny influenza virus was found to be significantly reduced in titer in 3-deazauridine-treated Madin-Darby canine kidney cell cultures at 12 to 24 hr after infection. Although the precise biochemical mechanism of action of this antimetabolite's antiviral activity is not known, the compound does not appear to exert a direct virucidal effect on the influenza virion itself.