Inorganic nitrate supplementation attenuates platelet reactivity in healthy male volunteers

Abstract

Vegetables possessing high levels of inorganic nitrate provide a source of vasoprotective nitric oxide, via generation of nitrite intermediate, that attenuates ex-vivo stimulated platelet aggregation. We investigated whether potassium nitrate supplementation might replicate these effects. Twenty-four healthy volunteers (12 men and 12 women) consented to participate in a randomised double-blind cross-over study of potassium nitrate (KNO3, 8 mmol) vs. potassium chloride (KCl, 8 mmol placebo) capsules. Blood was collected before and 3 h following intervention. Ozone chemiluminescence assessment of plasma demonstrated elevations of circulating [nitrite] above baseline at 3 h (males 0.35 ± 0.49 vs 0.54 ± 0.02 μM, P KNO 3 supplementation causes a rise in circulating nitrite levels in both sexes but attenuates platelet reactivity of male but not female volunteers. Moreover, we find that nitrite activity on platelets requires the presence of whole blood. Our findings suggest that nitrate supplementation may provide an additional option in anti-platelet medication.