[In vitro lipid-lowering and fibrinolytic effects of regulatory leucine-containing glyprolines in human blood].

The lipid-lowering, fibrinolytic, and anticoagulant effects of leucine-containing glyprolines, Pro-Gly-Pro-Leu and Leu-Pro-Gly-Pro, were studied in vitro in the blood of patients with disorders of lipid metabolism. The lipid-lowering impact of glyprolines and their ability to reduce the polymerization and to increase the depolymerization of fibrin in human blood were found. Possible mechanisms of lipolytic action of peptides by means of modulation of the lipid-dependent phospholipase A2 were proposed.

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

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.