title: Effects of magnesium on platelet aggregation and adhesion. Magnesium modulates surface expression of glycoproteins on platelets in vitro and ex vivo.
abstract: Magnesium deficiency and its association with platelet hyperreactivity has been well recognised in a variety of diseases including myocardial infarction, preeclampsia, and diabetes. In order to investigate potential effects of intravenous Mg2+ supplementation, platelet function was studied by measurements of in vitro bleeding time (BT) and of fibrinogen (Fg)-mediated aggregation of washed platelets. In addition, the effect of Mg2+ on platelet adhesion onto immobilised Fg, on Fg binding to activated platelets, and on surface expression of GMP-140 or GP53 was evaluated. Mg2+ (4 mM) prolonged in vitro BT by 30% and inhibited Fg-mediated aggregation significantly, independent of the agonist used to initiate platelet aggregation (ADP, collagen, epinephrine, thrombin, phorbol ester). Adhesion of resting platelets to immobilised Fg was reduced by 50% in the presence of 2 mM Mg2+. Moreover, Mg2+ reduced Fg binding to ADP- or collagen-stimulated platelets as well as surface expression of GMP-140 with an IC50 of approximately 3 mM. Intravenous administration of Mg2+ to healthy volunteers inhibited both ADP-induced platelet aggregation (p < 0.05) by 40% and binding of Fg or surface expression of GMP-140 by 30% (p < 0.05). Thus, pharmacological concentrations of Mg2+ effectively inhibit platelet function in vitro and ex vivo.
authors.affiliation: First Medical Department, Technical University, Munich, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Gawaz
authors.forename: I
authors.initials: I
authors.lastname: Ott
authors.forename: A J
authors.initials: AJ
authors.lastname: Reininger
authors.forename: F J
authors.initials: FJ
authors.lastname: Neumann
mesh_terms: D001760:Bleeding Time; D005069:Evaluation Studies as Topic; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology*; D010973:Platelet Adhesiveness / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D010980:Platelet Membrane Glycoproteins / Q000187:drug effects*; D011485:Protein Binding; D012016:Reference Values
chemical_list: D010975:Platelet Aggregation Inhibitors; D010980:Platelet Membrane Glycoproteins; D005340:Fibrinogen; D008274:Magnesium