S-nitrosoderivative of a recombinant fragment of von Willebrand factor (S-nitroso-AR545C) inhibits thrombus formation in guinea pig carotid artery thrombosis model.
Antiplatelet drugs are the mainstays of therapy for acute and chronic cardiovascular diseases. S-nitroso-AR545C - an S-nitrosoderivative of a recombinant von Willebrand factor fragment AR545C spanning Ala 444 to Asp 730 and containing an Arg 545 Cys mutation, was previously found to inhibit ristocetin- and ADP-induced platelet aggregation and the interaction of platelets with extracellular matrix (ECM). In the current study we tested the antithrombotic properties of S-nitroso-AR545C on guinea pig platelets and in a platelet-rich thrombosis model in the guinea pig. Preincubation of guinea pig platelets with 0.1 microM of S-nitroso-AR545C decreased ristocetin-induced agglutination by 40% (p = 0.009) and completely abolished ADP-induced aggregation (p <0.0001). At concentration of 1.0 microM, S-nitroso-AR545C completely inhibited platelet adhesion (represented by surface coverage - SC) and decreased aggregate formation (represented by average aggregate size - AS) by more than 50%. Treatment of guinea pigs with 1.0 mg/kg S-nitroso-AR545C resulted in a significantly delayed time to arterial occlusion (31.7+/-6.0 min vs. 13.9+/-3.2 min, p <0.02). Similarly, total patency time was longer in the group injected with S-nitroso-AR545C compared to the control group. However, the difference was not statistically significant (33.8+/-6.3 min vs. 20.2+/-3.3 min, p = 0.07). No change in platelet count, hematocrit and bleeding time was observed 60 min after injection compared to baseline. In contrast, a significant decrease in SC (p <0.0001) and AS (p <0.01) were observed 60 min after the injection of S-nitroso-AR545C, whereas no change in these parameters was observed in the control group. These observations indicate that S-nitroso-AR545C exhibits significant antiadhesive and antiaggregating effects in-vitro and inhibits clot formation in-vivo suggesting that this compound may have potential therapeutic advantages.
Gurevitz
O
O
The Neufeld Cardiac Research and Thrombosis and Hemostasis Institutes, Sheba Medical Center, Tel Hashomer and Pathology Department, the Sackler Faculty of Medicine, Tel-Aviv University, Israel.
Eldar
M
M
Skutelsky
E
E
Tamarin
I
I
Shenkman
B
B
Eskaraev
R
R
Castel
D
D
Loscalzo
J
J
Inbal
A
A
D000818:Animals; D002341:Carotid Artery Thrombosis / Q000188:drug therapy*; D004195:Disease Models, Animal; D006168:Guinea Pigs; D010446:Peptide Fragments / Q000494:pharmacology* / Q000627:therapeutic use; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D011994:Recombinant Proteins / Q000494:pharmacology / Q000627:therapeutic use; D014841:von Willebrand Factor / Q000494:pharmacology* / Q000627:therapeutic use
D010446:Peptide Fragments; D010975:Platelet Aggregation Inhibitors; D011994:Recombinant Proteins; C121400:S-nitroso-AR545C; D014841:von Willebrand Factor