Determination of plaque inhibitory activity of adenine arabinoside (9-beta-D-arabinofuranosyladenine) for herpesviruses using an adenosine deaminase inhibitor.

The in vitro susceptibility of type 1 and type 2 strains of Herpesvirus hominis to 9-beta-d-arabinofuranosyladenine (adenine arabinoside, ara-A) was measured in a system where deamination was inhibited. Under these conditions, it was possible to measure the activity of low concentrations of ara-A. It was determined that plaque inhibitory concentration for type 1 viruses was less than 3 mug/ml for all strains tested. The plaque inhibitory concentration for 7 of 10 type 2 strains was also less than 3 mug/ml. The method used identified and controlled the interaction between antiviral agent (ara-A) and the indicator system, human skin fibroblastic cells. Otherwise, metabolism of ara-A resulted in rapid enzymatic degradation and loss of antiviral activity.