Interferon-inducing activity of dipyridamole in mice

The kinetics of interferon (IFN) production was studied in mice after intraperitoneal (i.p.) and oral administrations of dipyridamole. The substance showed a high IFN-inducing activity when given orally at single doses ranging from 12.5 to 100 mg/kg (1/21.5-1/172 of the single LD50 value): peak titres of 2048-4096 IU/ml in the blood serum were reached at 48 hr; elevated IFN levels persisted until day 5 after administration of the inducer. Significantly lower IFN titres were found after i.p. injection.