Effects of peptide Pro-Gly-Pro-Leu under conditions of normal hemostasis and thrombus formation in rats

Abstract

Tetrapeptide Pro-Gly-Pro-Leu in vitro effectively inhibited platelet aggregation over the entire range of studied concentrations (10(-12)-10(-3) M). In concentrations of 10(-9)-10(-3) M it exhibits fibrinolytic activity and in concentrations of 10(-5)-10(-3) M has anticoagulant properties. Under in vivo conditions the analyzed tetrapeptide in a dose of 1 mg/kg increased anticoagulant, total and fibrin depolymerizating activities and increased activity of plasminogen activator. Intravenous administration produced more pronounced anticoagulant effect and leads to a greater increase in activity of plasminogen activator than intranasal administration. Tetrapeptide Pro-Gly-Pro-Leu also exerts antithrombotic effect. Preliminary repeated intranasal administration of the peptide before blood clot formation reduces the weight of fresh fibrin clots.