The Effect of Neuraminidase on Platelet Aggregation Induced by ADP, Norepinephrine, Collagen or Serotonin

Abstract

SummaryIncubation of human platelet-rich plasma (PRP) with neuraminidase enhanced platelet aggregation induced by adenosine diphosphate (ADP), norepinephrine, collagen or serotonin. Both first and second phases of ADP- and norepinephrine -induced aggregation were enhanced. In two plasmas a second phase of ADP-induced aggregation occurred after incubation with neuraminidase, but not in the control preparations. In one plasma a second phase of serotonin-induced platelet aggregation occurred after incubation with neuraminidase. The incubation of PRP with exogenous N-acetylneuraminic acid (a product of the action of neuraminidase) had no effect on platelet aggregation. A possible explanation of the observed enhancement of platelet aggregation by neuraminidase is that the enzyme may have released sialic acid from platelet membranes and thereby reduced their net negative surface charge.