Uptake of Tritiated Folates by Human Bone Marrow Cells in Vitro
Uptake of Tritiated Folates by Human Bone Marrow Cells in Vitro
复制标题
人骨髓细胞对氚化叶酸的体外摄取
DOI：
10.1111/j.1365-2141.1971.tb07064.x
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发表时间：
1971
影响因子：
6.5
通讯作者：
V. Herbert
中科院分区：
文献类型：
--
作者：
J. Corcino;S. Waxman;V. Herbert
摘要使用长达4小时的孵育期，证明体外人骨髓细胞对氚化蝶酰谷氨酸（[3 H]PteGlu）的摄取是网织红细胞摄取的6倍。摄取具有温度依赖性，在37°C下4小时内增加，但在4°C下不增加;对于[3 H]甲基四氢叶酸（[3 H-CH 3] H4 PteGlu）的摄取，发现了类似的温度依赖性。[3 H]PteGlu吸收的最佳pH在7.4的范围内。摄取百分比随着[3 H]PteGlu浓度的增加而降低。与未标记的PteGlu预孵育降低了随后加入的[3 H]PteGlu的摄取，其减少量是与甲氨蝶呤预孵育的两倍，这表明甲氨蝶呤可能仅部分共享[3 H]PteGlu的摄取机制。[3 H]PteGlu摄取不受与二苯基乙内酰脲或巯基抑制剂预孵育的影响。人骨髓细胞对[3 H-CH 3] H4 PteGlu的摄取似乎约为[3 H]PteGlu摄取的两倍。研究结果支持人网织红细胞和骨髓细胞摄取叶酸的两种机制的概念：可能具有主要生理意义的能量依赖性主动载体机制，以及可能主要具有药理学意义的看似被动的扩散样机制。
Summary. Using incubation periods up to 4 hr, it was demonstrated that uptake of tritiated pteroylglutamic acid ([3H]PteGlu) by human bone marrow cells in vitro was in the range of six‐fold greater than uptake by reticulocytes. Uptake was temperature‐dependent, increasing during 4 hr at 37°C but not at 4°C; a similar temperature dependence was found for the uptake of [3H]methyltetrahydrofolate ([3H‐CH3]H4PteGlu). The pH optimum for [3H]PteGlu uptake was in the range of 7.4. Percentage uptake decreased as concentration of [3H]PteGlu increased. Preincubation with unlabelled PteGlu reduced uptake of subsequently added [3H]PteGlu by twice as much as did preincubation with methotrexate, suggesting that methotrexate may only partly share the uptake mechanism for [3H]PteGlu. [3H]PteGlu uptake was not affected by preincubation with diphenylhydantoin or a sulphydryl inhibitor. Uptake of [3H‐CH3]H4PteGlu by human bone marrow cells appeared to be approximately twice the uptake of [3H]PteGlu. The findings support the concept of two mechanisms for folate uptake by human reticulocytes and bone marrow cells: an energy‐dependent, active carrier mechanism probably of primary physiologic significance, and a seemingly passive diffusion‐like mechanism, probably primarily of pharmacologic significance.