ASCORBIC-ACID STATUS - BIOCHEMICAL AND CLINICAL CONSIDERATIONS
ASCORBIC-ACID STATUS - BIOCHEMICAL AND CLINICAL CONSIDERATIONS
复制标题
DOI：
10.1093/ajcn/48.2.286
复制
发表时间：
1988-08-01
影响因子：
7.1
通讯作者：
LABBE, RF
中科院分区：
文献类型：
--
作者：
LEE, W;DAVIS, KA;LABBE, RF
在未打开的真空采血管中，抗坏血酸（AA）和脱氢抗坏血酸（DHAA）在全血中稳定。在25 ° C下，血浆中DHAA的氧化是不可逆且快速的。C，但不是4。C. AA + DHAA在全胃肠外营养液中的半衰期> 24 h。描述了二硫苏糖醇还原DHAA的条件，然后测定总AA，其中DHAA由差异确定。在健康和糖尿病受试者中，DHAA占总血浆AA + DHAA的< 5%。感染和产后应激导致每单位血液中多形核白细胞（PMN）AA含量无显着变化，但每细胞AA含量降低。当葡萄糖浓度增加时，中性粒细胞对AA摄取的Km增加一倍。这些化学和生理因素与维生素在血浆和细胞之间的快速移动相结合，表明AA状态的可靠指标仍有待确定。
Ascorbic acid (AA) plus dehydroascorbic acid (DHAA) was stable in whole blood in unopened vacutainer tubes. Oxidation of DHAA in plasma was irreversible and rapid at 25.degree. C but not at 4.degree. C. The half-life of AA + DHAA in total parenteral nutrition solutions was > 24 h. Conditions are described for dithiothreitol reduction of DHAA followed by assay of total AA, with DHAA being determined by difference. DHAA accounted for < 5% of the total plasma AA + DHAA in both healthy and diabetic subjects. Infection and postpartum-induced stresses resulted in no significant change in the AA content of polymorphonuclear leukocytes (PMN) per unit of blood but AA content per cell was decreased. When glucose concentration was increased, the Km for AA uptake by PMNs doubled. These chemical and physiological factors combined with the rapid movement of the vitamin between plasma and cells suggest that a reliable indicator of AA status remains to be identified.