[A quantitative study of human platelet membrane glycoproteins using immunocolloidal gold under the electron...

Two human platelet membrane glucoproteins (GP) and the quantitative changes of them induced by high shear stress (HSS) were studied using SZ-2 and SZ-21 monoclonal antibodies against GPIb and GPIIb/IIIa respectively by means of immunocolloidal gold technique with electron microscopy. Exposure to HSS (50 dynes/cm2, 5 min; 100 dynes/cm2, 3 min) resulted in the transformation of platelets from native smooth discs to activated spiny spheres followed by the centralization of organelles and lysis or aggregation of platelets. The results showed that resting platelets with few gold probes were turned into activated platelets by HSS with increased gold probes which represent the quantity of GPIb or GPIIb/IIIa. HSS also caused a specific platelet reaction--lysis. In the process of platelet lysis, platelet GPIIb/IIIa were increasingly condensed. On the contrary, GPIb reduced gradually. It suggests that the increase of GPIIb/IIIa under HSS may be one of the causes inducing platelet adhesion, release and aggregation at the opening of branched vessels, curved arteries, stenosed or partially occluded arteries due to local spasm.