Modulation of platelet aggregation by native DNA - initial description of platelet receptor type, number and discrimination for native DNA.
Native DNA (dsDNA) induces the aggregation of isolated human platelets. Using isotopically labeled dsDNA (125I-dsDNA) and Scatchard analysis, a single class of platelet receptor was detected with a KD = 190 pM and numbering approximately 275/platelet. This receptor was discriminatory in that heat denatured dsDNA, poly A, poly C, poly C x I and poly C x poly I failed to substantially inhibit either the platelet binding of, or platelet aggregation induced by, dsDNA; by themselves, these polynucleotides were ineffective as platelet agonists. However, poly G, poly I and poly G x I effectively and competitively inhibited platelet binding of the radioligand, independently activated the platelet and when used at a sub-activating concentration decreased the extent of dsDNA stimulated platelet aggregation. These data depict a receptor on human platelets for dsDNA and perhaps certain additional polynucleotides and relate receptor-ligand interactions to a physiologic platelet function.
D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D004247:DNA / Q000494:pharmacology*; D006358:Hot Temperature; D006801:Humans; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D007553:Isotope Labeling; D010974:Platelet Aggregation / Q000187:drug effects*; D010976:Platelet Count; D011119:Polynucleotides; D011817:Rabbits; D013997:Time Factors
D007457:Iodine Radioisotopes; D011119:Polynucleotides; D004247:DNA