The binding of Fgn to GPIIb / IIIa has confirmed that there are two distinct amino acid sequences within the Fgn molecule that are responsible for mediating its attachment to GP IIb / IIIa receptor. In addition to monoclonal antibodies, the binding function of GP IIb / IIIa can be blocked by synthetic small peptides containing the RGD and APLRV sequence. In our preliminary study it was found that besides inhibition of platelet aggregation and thrombus formation RGDS showed vasodilation effects as well. In an attempt to confirm the vasodilation effect of RGDS related peptides, RGDF, APLRV, APLRVRGDS and APLRVRGDF were investigated. The effects of these synthetic peptides on rat aortic strips pretreated with NE in vitro were observed. The relaxing extents of contracted strips for the peptides at three doses (10 5 mol / L, 10 6 mol / L and 10 7 mol / L) were recorded.
P6A was able to increase coronary blood flow and improve hemodynamics in the coronary thrombosis model of dogs In the binding of fibrinogen to GP IIb/IIIa,RGD is the key sequence In the present paper the effects of the coupling compounds of P6A and its derivatives,QP6A with RGDS,RGDV and RGDF were tested The effects of the coupling compounds so obtained on carotid thrombosis in rats were investigated At the dose of 5 μmol/kg,RGDS and RGDV exhibited no antithrombotic effects,whereas at 2.5μmol/kg RGDF decreased the dry-weight ofthrombus significantly On the other hand,P6A(5μmol/kg)and QP6A(2.5μmol/kg)showed significant antithrombosis activities.All of the coupling compounds,except P6A-RGDF and QP6A-RGDF,had potent antithrombosis effects.
