[Antithrombotic effect of piavit--a substance from the medicinal leech (Hirudo medicinalis), containing prostanoid and destabilase fractions].

The protective antithrombotic effects of piyavit, a novel pharmacological preparation from the medicinal leech, its water extract concentrated and diluted 1600-fold, the piyavit fraction containing leech prostanoids and highly purified destabilase, epsilon-(gamma-Glu)-Lys-isopeptidase isolated from the medicinal leech (Hirudo medicinalis), have been studied. All the preparations under study inhibited clot formation in rat mesanterium arterioles stimulated by laser energy, contained leech prostanoids immunoenzymatically identified as 6-keto-PgF1 alpha and inhibited platelet aggregation induced by ADP. The putative mechanism of their antithrombotic effect is discussed.