Abstract
9-β- d -Arabinofuranosyladenine (Ara-A) effectively inhibited the production of infectious vesicular stomatitis virus (VSV) in MDBK cells. Furthermore, inhibition was shown to begin as early as the first 3 hr of infection. Studies employing 3 H- l -leucine indicated that Ara-A did not affect protein synthesis in uninfected cells, although it did cause a marked stimulation of protein synthesis in VSV-infected cells during the log phase of the growth cycle. Puromycin, an inhibitor of protein synthesis, was a more effective viral inhibitor than Ara-A. However, the combination of Ara-A and puromycin was less effective than puromycin alone except when present for long time periods. Short-term labeling experiments with 3 H-uridine demonstrated that Ara-A depressed ribonucleic acid (RNA) synthesis in uninfected cells, whereas periods of stimulation and depression of radioisotope incorporation occurred in infected cells. The results support the notion that Ara-A is incorporated into RNA early during viral replication.