Regulation of Human Platelet Adhesion with Ascorbic Acid

Morphofunctional characteristics of human platelets in the presence of 0.1-5 mM ascorbic acid were studied. The platelet ability to form lamellae and the preservation of granules in platelets in suspension and during adhesion were evaluated. Ascorbic acid in concentrations of 0.1-1 mM induced no visible changes in platelet structure and did not affect their adhesion activity, but suppressed lamella growth and degranulation in adherent platelets in a dose-dependent manner. The maximum preservation of granules was revealed in the presence of 0.5 mM ascorbic acid (55% in 1 h from the moment of adhesion). In the presence of 2-5 mM ascorbic acid, spontaneous activation and degranulation of platelets was observed. Thus, ascorbic acid is capable of both suppressing and stimulating platelet activity. In concentrations of 0.5-1 mM ascorbic acid can be used to stabilize granules in adherent platelets.