Sodium-dependent ascorbic and dehydroascorbic acid uptake by SV-40-transformed retinal pigment epithelial cells.
Sodium-dependent ascorbic and dehydroascorbic acid uptake by SV-40-transformed retinal pigment epithelial cells.
复制标题
SV-40 转化的视网膜色素上皮细胞对钠依赖性抗坏血酸和脱氢抗坏血酸的摄取。
DOI：
10.1159/000267272
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发表时间：
1993
影响因子：
2.1
通讯作者：
Lin,T
中科院分区：
文献类型：
--
作者：
Lam,KW;Yu,HS;Glickman,RD;Lin,T
目前的数据证实了以前的研究与其他类型的细胞，抗坏血酸和脱氢抗坏血酸通过不同的转运到SV-40转化的视网膜色素上皮细胞。这些实验在96孔培养板上生长的细胞上进行。抗坏血酸被一种高亲和力转运蛋白吸收到细胞中，Km= 0.041 mmol/l，Vmax较低，为2.74 pmol/min/孔。脱氢抗坏血酸被低亲和力转运蛋白吸收，Km= 5.67 mmol/l;然而，Vmax为325.5 pmol/min/孔。抗坏血酸和脱氢抗坏血酸的吸收都依赖于钠浓度。抗坏血酸的摄取不涉及氧化反应步骤，因为[14 C]-抗坏血酸的摄取不受过量未标记的脱氢抗坏血酸的存在的影响。
The present data confirmed previous studies with other cell types that ascorbic acid and dehydroascorbic acid are transported through different transporters into SV-40-transformed retinal pigment epithelial cells. These experiments were performed on cells grown on 96-well culture plates. Ascorbic acid was taken up into the cell by a high-affinity transporter with Km= 0.041 mmol/l and a low Vmax of 2.74 pmol/min/well. Dehydroascorbic acid was taken up by a low-affinity transporter with Km= 5.67 mmol/l; however, the Vmaxwas 325.5 pmol/min/well. The uptake of both ascorbic acid and dehydroascorbic acid was dependent on the sodium concentration. The uptake of ascorbic acid does not involve oxidation-reaction steps because the uptake of [14C]-ascorbate was unaffected by the presence of an excess amount of unlabelled dehydroascorbic acid.