MODULATIVE EFFECTS OF CELL-ADHESION PEPTIDE (ARG-GLY-ASP-SER) ON THE AGGREGATION OF STIMULATED PLATELETS FROM OPHTHALMIC PATIENTS

Adhesion proteins are cofactors in the aggregation of human platelets, and can mediate the ADP-induced response of these cells. It was shown that the synthetic cell adhesion peptide, Arg-Gly-Asp-Ser inhibits the aggregation of platelets from normal donors and ophthalmic patients with diabetic retinopathy, glaucoma and retinal vein occlusion. This effect increases in the relative order of activity retinal vein occlusion greater-than-or-equal-to glaucoma greater-than-or-equal-to diabetic retinopathy > control. Deaggregation due to the peptide appeared to be diminished in the order control (normal) > diabetic retinopathy > glaucoma > retinal vein occlusion after its addition at the maximum of aggregation curve. It is concluded that there are differences in the ability of Arg-Gly-Asp-Ser peptide to block the fibronectin adhesion receptor on ADP stimulated platelets from different clinical groups.