Inorganic nitrate supplementation attenuates platelet reactivity in healthy male volunteers

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• 作者：Shanti Velmurugan ; Vanessa Pearl ; Sheridan Davies ; Manpreet Bahra ; Suborno Ghosh ; Vikas Kapil ; Amrita Ahluwalia
• 刊名：Nitric Oxide
• 出版年：2012
• 出版时间：15 July, 2012
• 年：2012
• 卷：27
• 期：supp_S
• 页码：S27-S28
• 全文大小：1K

文摘

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 ¡À 0.49 vs 0.54 ¡À 0.02 ¦ÌM, P < 0.01; females 0.43 ¡À 0.04 vs 0.85 ¡À 0.1¦ÌM, p < 0.01) following nitrate ingestion, no changes were evident after placebo. ADP (56.4 ¡À 2.5 ¦¸s) and collagen (72.0 ¡À 3.0 ¦¸s) caused (P < 0.01 vs. PBS) platelet aggregation, using whole blood impedance aggregometry, that was not different between the sexes. In addition, whilst ADP-induced platelet aggregation of whole blood was reduced (P < 0.01) after nitrate ingestion in males (not females) no change in aggregation was evident after placebo. Responses to collagen were similar in both limbs. Pretreatment of whole blood with nitrite caused concentration-dependent inhibition of ADP- but not collagen-induced aggregation. This effect of nitrite on aggregation was absent if nitrite was incubated with purified platelets. Thus, we show that 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.