Retief F P, Huskisson Y J
J Clin Pathol. 1970 Nov;23(8):703-7. doi: 10.1136/jcp.23.8.703.
In normal serum, saline dialysis for 48 hours in Visking casing resulted in folate clearance closely comparable to that produced by haemoglobin-coated charcoal adsorption, except in kwashiorkor where charcoal removed a greater proportion of folate. Pre- and post-dialysis values probably represented total and bound folate, respectively. Urinary folate consisted almost exclusively of dialyzable or free folate. Folate in saliva, bile, and erythrocytes consisted of dialyzable and non-dialyzable fractions; gastric juice contained minimal amounts of folate. In spite of low serum albumin in kwashiorkor the bound folate fraction was increased rather than decreased; in myeloma with hyperglobulinaemia there was no increase in the bound folate fraction. Nephrotic urine did not contain excess folate, but pregnancy urine (third trimester) showed increased total folate.Serum, chromatographed on Sephadex G-25, produced two folate peaks, only the first being associated with serum proteins. Urine contained only a second folate peak corresponding to the elution peak of pteroyl-monoglutamic acid (PGA). Adsorption studies with charcoal coated with ;molecular sieves' of varying size suggested that the predominant serum folate binder was of molecular weight 70,000-120,000. It is unlikely to be albumin.
在正常血清中，用维克斯汀肠衣进行48小时的盐水透析，叶酸清除率与血红蛋白包被的活性炭吸附法所产生的清除率相近，但在夸希奥科病患者中，活性炭去除的叶酸比例更高。透析前和透析后的数值可能分别代表总叶酸和结合型叶酸。尿叶酸几乎完全由可透析或游离叶酸组成。唾液、胆汁和红细胞中的叶酸由可透析和不可透析部分组成；胃液中叶酸含量极少。尽管夸希奥科病患者血清白蛋白水平较低，但结合型叶酸部分增加而非减少；在高球蛋白血症的骨髓瘤患者中，结合型叶酸部分并未增加。肾病患者的尿液中不含过量叶酸，但妊娠后期尿液中的总叶酸含量增加。在葡聚糖凝胶G - 25上进行层析的血清产生了两个叶酸峰，只有第一个峰与血清蛋白相关。尿液中仅含有对应于蝶酰单谷氨酸（PGA）洗脱峰的第二个叶酸峰。用不同大小的“分子筛”包被的活性炭进行吸附研究表明，主要的血清叶酸结合剂分子量为70,000 - 120,000。它不太可能是白蛋白。
