Inhibition of viral RNA synthesis by 1-methyl-1-nitrosourea

The effect of 1-methyl-1-nitrosourea on the synthesis of viral RNA of Poliovirus in KB-cells has been examined. It was found that 1-methyl-1-nitrosourea at concentration of 400 micrograms/ml blocked the synthesis of viral RNA in Poliovirus-infected KB-cells irrespective of whether it was added to culture medium immediately after virus adsorption or 2 h later. Furthermore, the inhibitory effect of 1-methyl-1-nitrosourea on the growth of Poliovirus is comparable to that of Herpes simplex virus grown in KB-cells. These findings suggest that 1-methyl-1-nitrosourea does not discriminate between these two types of viruses and moreover that the viral RNA of Poliovirus could also be the target for the action of the drug.