Availability of monoglutamyl and polyglutamyl folates in normal subjects and in patients with coeliac sprue.
Availability of monoglutamyl and polyglutamyl folates in normal subjects and in patients with coeliac sprue.
复制标题
正常受试者和乳糜泻患者中单谷氨酰叶酸和多谷氨酰叶酸的可用性。
作者：
C. Halsted;A. Reisenauer;B. Shane;T. Tamura
在六名正常受试者和四名乳糜泻患者中评估了肠道叶酸吸收情况，并在饮食麸质排除治疗前后进行了研究。比较了 3H-蝶酰单谷氨酸和蝶酰 14C-谷氨酰六谷氨酸灌注空肠的管腔消失，以及灌注和叶酸组织饱和剂量后每种同位素 48 小时尿回收率。标记的尿叶酸由叶酸、10-甲酰四氢叶酸和5-甲基四氢叶酸组成。在各组中，3H的尿回收率显着高于14C的尿回收率，证实了空肠灌注的证据，即单谷氨酰叶酸的利用率大于聚谷氨酰叶酸的利用率。根据尿液回收数据，两种叶酸在未经治疗的口炎性腹泻中吸收不良，但在治疗后吸收正常。假设吸收的标记叶酸通过肠胃外冲洗剂量均匀位移，则尿同位素回收率大于灌注的近端空肠段的管腔叶酸消失的发现表明远端小肠对腹腔口炎性腹泻中叶酸吸收的适应。
Intestinal folate absorption was assessed in six normal subjects and in four patients with coeliac sprue who were studied before and after treatment by dietary gluten exclusion. Comparisons were made of the luminal disappearance from the perfused jejunum of 3H-pteroylmonoglutamate and pteroyl 14C-glutamylhexaglutamate, and of the 48-hour urinary recovery of each isotope after perfusion and a tissue saturating dose of folic acid. The labelled urinary folates consisted of folic acid, 10-formyltetrahydrofolate, and 5-methyltetrahydrofolate. In each group urinary recovery of 3H was significantly greater than that of 14C, confirming the evidence from jejunal perfusion that the availability of monoglutamyl folate is greater than that of polyglutamyl folate. According to the urinary recovery data, both folates were poorly absorbed in untreated coeliac sprue, but were normally absorbed after treatment. Assuming uniform displacement of the absorbed labelled folates by the parenteral flushing dose, the finding of greater urinary isotope recovery than of luminal folate disappearance from the perfused proximal jejunal segment suggests an adaptation of the distal small bowel for folate absorption in coeliac sprue.