TESTICULAR AND PLASMA ASCORBIC-ACID LEVELS IN MICE FOLLOWING DIETARY-INTAKE - A HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ANALYSIS
TESTICULAR AND PLASMA ASCORBIC-ACID LEVELS IN MICE FOLLOWING DIETARY-INTAKE - A HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ANALYSIS
复制标题
DOI：
10.1016/0378-4347(93)80314-t
复制
发表时间：
1993-05-05
期刊：
影响因子：
--
通讯作者：
RAO, DV
中科院分区：
文献类型：
--
作者：
HARAPANHALLI, RS;HOWELL, RW;RAO, DV
本文报道了一种改进的缓冲体系，用于小鼠血浆和睾丸中维生素C的反相高效液相色谱紫外检测分析。由0.1 M NaH 2 PO 4和0.2 mM Na 2 EDTA组成的缓冲液（用正磷酸调节至pH 3.1）分离了抗坏血酸（AA）峰，从而可以明确定量化学品。该方法也适用于测定脱氢抗坏血酸后，其还原为抗坏血酸，并克服了AA的稳定性在以前报道的程序中遇到的问题。使用本技术，在小鼠中开始喂食富含维生素C的饮食（1%，w/w）后3至29天研究血浆和睾丸中维生素水平的变化。到第8天，血浆AA水平升高至对照组的2.5倍以上。与此相反，睾丸AA水平在第12天略有增加（1.2倍），此后维持在接近对照值的水平。看来在血浆中有效的反馈抑制机制在睾丸中不起作用。这些发现具有临床意义，因为睾丸AA水平不会因膳食摄入维生素C而发生显著变化，而血浆AA水平确实显示出增加。
A modified buffer system is reported for the analysis of vitamin C in mouse plasma and testes, on a reversed-phase high-performance liquid chromatographic column with ultraviolet detection. The buffer, consisting of 0.1 M NaH2PO4 and 0.2 mM Na2EDTA adjusted to pH 3.1 with orthophosphoric acid, resolved the ascorbic acid (AA) peak allowing clear quantitation of the chemical. The method is also applicable to the assay of dehydroascorbic acid after its reduction to ascorbic acid, and overcomes problems of AA stability encountered in previously reported procedures. Using the present technique, variations in the vitamin levels of plasma and testes are studied from 3 to 29 days after the commencement of feeding a vitamin C-rich diet (1%, w/w) in mice. The plasma AA levels were elevated above the controls by a factor of 2.5 by day 8. Contrary to this, testicular AA levels increased marginally (1.2-fold) by day 12 and were maintained at levels close to the control values thereafter. It appears that the feedback inhibition mechanism which is effective in plasma is not operational in the testes. The findings are of clinical significance in that testicular AA levels do not change significantly as a result of dietary intake of vitamin C, whereas plasma AA levels do show an increase.