Dextrans “in vitro” do not inhibit the hemorheological mechanisms of platelet function

Abstract

There is in vivo evidence that dextrans have antiplatelet effect. We have performed a series of experiments to elucidate a possible hemorheological action through which dextrans might alter platelet function. A perfusion system allowing morphometric evaluation of platelet interaction with subendothelial structures was used for this purpose. Perfusion experiments were performed in the presence of dextran 40 or 70 (10% v:v) or with blood reconstituted with dextran-incubated red blood cells. Experiments in which blood or red blood cells were treated with the same proportion of 4% human serum albumin (HSA) were used as a control. Changes in the mechanical properties of red blood cells were morphologically assessed with a micropipette aspiration technique. None of the dextrans used modified the mechanical properties of red blood cells. However, both dextran 40 (D40) and dextran 70 (D70) increased the intensity of the interaction of platelets with subendothelial structures when added to whole blood. Our experiments suggest that when added in vitro dextrans do not alter the hemorheological mechanisms of platelet function.