Inhibition of agonist-induced platelet aggregation by magnesium sulfate warrants its use as an alternative in vitro anticoagulant in pseudothrombocytopenia

Abstract

MgSO₄ is effective in preventing spontaneous in vitro platelet agglutination in anticoagulant-induced pseudothrombocytopenia (PTCP). In order to learn more about its potential as an in vitro anticoagulant, platelets from MgSO₄-anticoagulated blood were stimulated by several differentially-acting agonists (ADP, ARA, TRAP, epinephrine, collagen and ristocetin). Platelet aggregation in blood samples from 11 and 17 volunteers was measured by light-transmission aggregometry (LTA) according to Born and impedance aggregometry (Multiplate^TM), respectively. Agonist-induced platelet aggregation was markedly lower in MgSO₄-anticoagulated samples when compared with citrate-anticoagulated samples (decrease of 95.75% (ristocetin), 69.02% (collagen) and 75.73% (epinephrine)) or hirudin-anticoagulated samples (decrease of 85.99% (ADP), 80.98% (ARA), 77.24% (ristocetin), 54.37% (collagen) and 50.14% (TRAP)). The anti-aggregatory effect of MgSO₄ is dose-dependent and readily detectable at a concentration of 7.5 mmol/l. Analysis of the agonist signaling pathways suggest that MgSO₄ interferes with the final step of platelet aggregation, namely the intracellular mobilization of Ca²⁺.

Keywords:

• Impedance aggregometry
• light transmission aggregometry (LTA)
• magnesium sulfate (MgSO₄)
• platelet function

Acknowledgements

The authors thank Prof. Günther Kundt (Institute for Biostatistics and Informatics in Medicine and Aging Research, Rostock University Medical Center) for his statistical advice.

Declaration of interest

The authors report no conflict of interest.

Contribution of each author

SM defined the study design and performed the experiments, PSW wrote parts of the manuscript, KD was responsible for data acquisition and CB contributed to the discussion and corrected the final manuscript.