Abstract
The effects of sodium alginate on the adhesion and aggregation of rat and human platelets were examined to investigate the role of this material in haemostasis. The adhesion of the rat and human platelets on the surface of glass beads, as well as the platelet aggregation in vitro, were enhanced in the presence of sodium alginate. This effect was dependent of the molecular weight and concentration of sodium alginate in the medium. The scanning and transmission electron microscopic observations revealed that the aggregated platelets, in the presence of sodium alginate, lost their discoid shape and formed irregular spheres with extended pseudopods. The number of microfibrils in the cytoplasm of these platelets markedly increased. These findings demonstrated that the aggregation of platelets was apparently enhanced in the presence of sodium alginate. Sodium alginate did not inhibit the aggregation of platelets induced by adenosine diphosphate or collagen, but instead, accelerated the action of these agents. Sodium alginate had no direct effects upon the release of serotonin from platelets and arachidonic acid cascade. The results of the present study suggest that the enhancing effect of sodium alginate on the adhesion and aggregation of platelets may have a significant role in haemostasis.
