PGI2-generation and antithrombotic activity of orally administered defibrotide

Defibrotide, a polydeoxyribonucleotide extracted from mammalian organs (laboratory code Fraction P), displays antithrombotic activity after oral administration on different animal species. This activity is also demonstrated in a typical local thrombonecrotic hemorrhagic lesion caused by endotoxin in rabbit (Shwartzman reaction). Defibrotide prevents and antagonizes this kind of lesion in a dose dependent and in a long lasting way. The ability of Defibrotide to increase generation of PGI2 from vascular tissue following oral administration, is demonstrated and the mechanism of this phenomenon discussed.