Impact of high dose vitamin C on platelet function

• 作者: Alpha A FowlerⅢ Bassem M Mohammed Bernard J Fisher4 Charles E Chalfant Daniel Contaifer Jr Dayanjan S Wijesinghe Donald F Brophy Erika J Martin Kimberly W Sanford Ramesh Natarajan Urszula Osinska Warncke
• 来源期刊: 世界重症医学杂志
• 学科: 医学
• 关键词: PLATELET function THROMBOELASTOGRAPHY FLOW CYTOMETRY PLATELET LIPIDOMICS VITAMIN C
• 年，卷（期）: 2017,（1）
• 页码范围: 37-47
• 页数: 11页
• 分类号: R

摘要

AIM To examine the effect of high doses of vitamin C(VitC)on ex vivo human platelets(PLTs).METHODS Platelet concentrates collected for therapeutic or prophylactic transfusions were exposed to:(1)normal saline(control);(2)0.3 mmol/L VitC(Lo VitC);or(3)3 mmol/L VitC(Hi VitC,final concentrations)and stored appropriately.The VitC additive was preservative-free buffered ascorbic acid in water,pH 5.5 to 7.0,adjusted with sodium bicarbonate and sodium hydroxide.The doses of VitC used here correspond to plasma VitC levels reported in recently completed clinical trials.Prior to supplementation,a baseline sample was collected for analysis.PLTs were sampled again on days 2,5 and 8 and assayed for changes in PLT function by:Thromboelastography(TEG),for changes in viscoelastic properties;aggregometry,for PLT aggregation and adenosine triphosphate(ATP)secretion in response to collagen or adenosine diphosphate(ADP);and flow cytometry,for changes in expression of CD-31,CD41a,CD62p and CD63.In addition,PLT intracellular VitC content was measured using a fluorimetric assay for ascorbic acid and PLT poor plasma was used for plasma coagulation tests[prothrombin time(PT),partial thrombplastin time(PTT),functional fibrinogen]and Lipidomics analysis(UPLC ESI-MS/MS).RESULTS VitC supplementation significantly increased PLTs intracellular ascorbic acid levels from 1.2 mmol/L at baseline to 3.2 mmol/L(Lo VitC)and 15.7 mmol/L(Hi VitC,P<0.05).VitC supplementation did not significantly change PT and PTT values,or functional fibrinogen levels over the 8 d exposure period(P>0.05).PLT function assayed by TEG,aggregometry and flow cytometry was not significantly altered by Lo or Hi VitC for up to 5 d.However,PLTs exposed to 3 mmol/L VitC for 8 d demonstrated significantly increased R and K times by TEG and a decrease in theα-angle(P<0.05).There was also a fall of 20 mm in maximum amplitude associated with the Hi VitC compared to both baseline and day 8 saline controls.Platelet aggregation studies,showed uniform declines in collagen and ADP-induc