The effect of prolil-glycil-proline (PGP) peptide and PGP-rich substances on haemostatic parameters of rat blood

The effect of intravenous and intranasal administration of proline-containi ng peptide, especially prolil-glycil-proline (PGP), on the haemostatic syst em of rats was investigated. Tripeptide PGP after single intravenous (0.2, 1.0 and 1.5 mg/kg) or intranasal (0.5 mg/kg) administration increased (P < 0.05) total fibrinolytic and fibrin depolymerizating (FDA) activities, and tissue plasminogen activator levels (t-PA), and decreased the plasmin inhib itors (PI) and activated factor XIII (factor XIIIa) levels in blood plasma. Repeated daily intranasal administration (5 days) of PGP produced a signif icant increase of anticoagulant and fibrinolytic activities (P < 0.05), and a decrease of platelet aggregation, PI and factor XIIIa levels in blood pl asma. Fibrinogen concentrations remained practically unchanged. Chronic per oral administration of gelatin (protein particularly rich of PGP, prolil-gl ycil, glycil-proline) as a food supplement significantly increased t-PA lev el (by 120%) at day 10 and FDA (by 290%) at day 14 in blood plasma. We also observed potent suppression of thrombus formation (venous thrombosis model ) by intranasal PGP administration. Therefore, PGP and some PGP-rich substa nces can be qualified as potent anticoagulant and antithrombotic agents. (C ) 2000 Lippincott Williams & Wilkins.