Ascorbic Acid Transport and Distribution in Human B Lymphocytes

1995 ◽  
Vol 317 (1) ◽  
pp. 208-214 ◽  
Author(s):  
P. Bergsten ◽  
R. Yu ◽  
J. Kehrl ◽  
M. Levine
Keyword(s):  
Ascorbic Acid ◽  
B Lymphocytes ◽  
Acid Transport ◽  
Ascorbic Acid Transport

Requirement for Na(+)-dependent ascorbic acid transport in osteoblast function

1995 ◽  
Vol 268 (6) ◽  
pp. C1430-C1439 ◽  
Author(s):  
R. T. Franceschi ◽  
J. X. Wilson ◽  
S. J. Dixon
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Disulfonic Acid ◽  
Acid Transport ◽  
Transport Activity ◽  
Intracellular Accumulation ◽  
Extracellular Medium ◽  
Isoascorbic Acid ◽  
Transport Inhibitors ◽  
Ascorbic Acid Transport

Ascorbic acid is necessary for expression of the osteoblast phenotype. We examined whether Na(+)-dependent transport is required for MC3T3-E1 preosteoblast cells to respond to vitamin C and investigated the role of membrane transport in the intracellular accumulation and function of ascorbate. MC3T3-E1 cells were found to possess a saturable, stereoselective, Na(+)-dependent ascorbic acid transport activity that is sensitive to the transport inhibitors sulfinpyrazone, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid, and phloretin. Transport activity showed no competition with glucose or 2-deoxyglucose and was not inhibited by cytochalasin B, indicating that it is distinct from known hexose transporters. On addition of 100 microM ascorbic acid to the extracellular medium, intracellular concentrations of 10 mM were reached within 5-10 h and remained constant for up to 24 h. A good correlation was observed between intracellular ascorbic acid concentration and rate of hydroxyproline synthesis. Although ascorbic acid was transported preferentially compared with D-isoascorbic acid, both isomers had equivalent activity in stimulating hydroxyproline formation once they entered cells. Marked stereoselectivity for extracellular L-ascorbic acid relative to D-isoascorbic acid was also seen when alkaline phosphatase and total hydroxyproline were measured after 6 days in culture. Moreover, ascorbic acid transport inhibitors that prevented intracellular accumulation of vitamin blocked the synthesis of hydroxyproline. Thus Na(+)-dependent ascorbic acid transport is required for MC3T3-E1 cells to achieve the millimolar intracellular vitamin C concentrations necessary for maximal prolyl hydroxylase activity and expression of the osteoblast phenotype.

scholarly journals Endocrine Regulation of Ascorbic Acid Transport and Secretion in Luteal Cells1

1996 ◽  
Vol 54 (2) ◽  
pp. 399-406 ◽  
Author(s):  
Biljana Musicki ◽  
Pinar H. Kodaman ◽  
Raymond F. Aten ◽  
Harold R. Behrman
Keyword(s):  
Ascorbic Acid ◽  
Endocrine Regulation ◽  
Acid Transport ◽  
Ascorbic Acid Transport

Ascorbic Acid Transport by Isolated Bovine Adrenal Cortical Cells*

Endocrinology ◽  
1980 ◽  
Vol 106 (3) ◽  
pp. 811-817 ◽  
Author(s):  
FRANCES M. FINN ◽  
PHILLIP A. JOHNS
Keyword(s):  
Ascorbic Acid ◽  
Acid Transport ◽  
Cortical Cells ◽  
Adrenal Cortical Cells ◽  
Ascorbic Acid Transport

Mitochondrial ascorbic acid transport is mediated by a low-affinity form of the sodium-coupled ascorbic acid transporter-2

2014 ◽  
Vol 70 ◽  
pp. 241-254 ◽  
Author(s):  
Carola Muñoz-Montesino ◽  
Francisco J. Roa ◽  
Eduardo Peña ◽  
Mauricio González ◽  
Kirsty Sotomayor ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Acid Transport ◽  
Acid Transporter ◽  
Ascorbic Acid Transport

scholarly journals Corticosteroids and ascorbic acid transport in adrenal cortex in vitro

1964 ◽  
Vol 92 (3) ◽  
pp. 564-573 ◽  
Author(s):  
SK Sharma ◽  
RM Johnstone ◽  
JH Quastel
Keyword(s):  
Ascorbic Acid ◽  
Adrenal Cortex ◽  
Acid Transport ◽  
Ascorbic Acid Transport

scholarly journals Ascorbic acid accumulation and transport in human fibroblasts

1993 ◽  
Vol 294 (2) ◽  
pp. 505-510 ◽  
Author(s):  
R W Welch ◽  
P Bergsten ◽  
J D Butler ◽  
M Levine
Keyword(s):  
Ascorbic Acid ◽  
Human Fibroblasts ◽  
Initial Step ◽  
Metabolic Inhibitors ◽  
Human Neutrophils ◽  
Acid Transport ◽  
High Affinity ◽  
Acid Accumulation ◽  
Dependent Transport ◽  
Ascorbic Acid Transport

As the initial step in the use of fibroblasts as a model system for ‘in situ kinetics’, ascorbic acid (vitamin C) accumulation in normal human fibroblasts was investigated for the first time. Ascorbic acid was transported into fibroblasts and accumulated against a concentration gradient up to 20-fold, as measured by h.p.l.c. with coulometric electrochemical detection. Ascorbic acid accumulation was mediated by two concentration-dependent transport activities. The first was a high-affinity activity with an apparent Km of 6 microM and an apparent Vmax. of 203 microM/h, and the second was a low-affinity activity with an apparent Km of 5 mM and an apparent Vmax. of 1.8 mM/h. Both activities were inhibited by metabolic inhibitors and inhibitors of ascorbic acid transport in human neutrophils. The low-affinity transporter could not be accounted for by diffusion. Although the high-affinity transport activity was comparable with that described for human neutrophils, the low-affinity transporter was different. These data provide the first evidence that two-component ascorbic acid transport may be a generalized mechanism for accumulation of this vitamin in humans.

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