A Possible Role for Nitric Oxide in the Antiaggregatory Effect of Magnesium

Objective: To examine the effects of magnesium alone and after preincubation with different concentrations of L-Arginine and N-nitro-L-arginine (L-NNA), the NOS inhibitor on the platelet aggregation stimulated by ADP. Methods: Blood was collected from the rhesus monkeys. Platelet rich plasma (PRP) was prepared and the aggregation was tested alone, after preincubation with different concentrations of magnesium (Mg 2+ ) and after preincubation with Mg 2+ and different concentrations of L-arginine or L-NNA. Aggregation was stimulated by ADP (10uM). Results: Magnesium significantly inhibited platelet aggregation. Preincubation with L-Arginine caused a further inhibition of aggregation which was statistically significant. Preincubation with L-NNA, partially reversed the antiaggregatory effect of Mg 2+ which was again statistically significant. Conclusion: The study suggests that nitric oxide (NO) may be partly responsible for the antiaggregatory effect of Mg 2+ .