AJCN North Carolina Research Campus
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Horne, D. W.
Right arrow Articles by Said, H. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Horne, D. W.
Right arrow Articles by Said, H. M.
Agricola
Right arrow Articles by Horne, D. W.
Right arrow Articles by Said, H. M.

American Journal of Clinical Nutrition, Vol 58, 80-84, Copyright © 1993 by The American Society for Clinical Nutrition, Inc

ORIGINAL RESEARCH COMMUNICATIONS

5-Methyltetrahydrofolate transport in basolateral membrane vesicles from human liver

DW Horne, KA Reed, J Hoefs and HM Said
Biochemistry Research Laboratory, Department of Veterans' Affairs Medical Center, Nashville, TN 37212-2637.

Transport of 5-methyltetrahydrofolate was studied in vesicles isolated from the basolateral membrane (BLM) of human liver. Uptake was mostly via transport into an osmotically active intravesicular space, with some membrane binding (approximately 20%). Transport was more rapid with an imposed pH gradient (pHout = 5.0, pHin = 7.5) as compared with either pHout = pHin = 5.0 or pHout = pHin = 7.5. Transport under the influence of a pH gradient showed a transient overshoot; uptake at 60 s was 4.2 times higher than at equilibrium (60 min). Transport in the presence of a pH gradient was saturable; apparent Km = 0.55 mumol/L and Vmax = 1.98 nmol.g protein-1.10 s-1. Transport was not saturable at pHout = pHin = 7.5. Transport was inhibited by the structural analogs 5- formyltetrahydrofolate, folic acid, and methotrexate, and was electroneutral in nature. These results suggest that 5- methyltetrahydrofolate transport in human BLM vesicles is via carrier- mediated cotransport with hydrogen ions.


This article has been cited by other articles:


Home page
 J. Nutr.Home page
M. F. Holick
The Vitamin D Epidemic and its Health Consequences
J. Nutr., November 1, 2005; 135(11): 2739S - 2748S.
[Abstract] [Full Text] [PDF]

Home page
 J. Nutr.Home page
C. L. Rock, M. D. Thornquist, A. R. Kristal, R. E. Patterson, D. A. Cooper, M. L. Neuhouser, D. Neumark-Sztainer, and L. J. Cheskin
Demographic, Dietary and Lifestyle Factors Differentially Explain Variability in Serum Carotenoids and Fat-Soluble Vitamins: Baseline Results from the Sentinel Site of the Olestra Post-Marketing Surveillance Study
J. Nutr., April 1, 1999; 129(4): 855 - 864.
[Abstract] [Full Text]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
J. Villanueva, E.-H. Ling, C. J. Chandler, and C. H. Halsted
Membrane and tissue distribution of folate binding protein in pig
Am J Physiol Regulatory Integrative Comp Physiol, November 1, 1998; 275(5): R1503 - R1510.
[Abstract] [Full Text] [PDF]

Home page
 NEJMHome page
M. K. Thomas, D. M. Lloyd-Jones, R. I. Thadhani, A. C. Shaw, D. J. Deraska, B. T. Kitch, E. C. Vamvakas, I. M. Dick, R. L. Prince, and J. S. Finkelstein
Hypovitaminosis D in Medical Inpatients
N. Engl. J. Med., March 19, 1998; 338(12): 777 - 783.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
C. D. Chancy, R. Kekuda, W. Huang, P. D. Prasad, J.-M. Kuhnel, F. M. Sirotnak, P. Roon, V. Ganapathy, and S. B. Smith
Expression and Differential Polarization of the Reduced-folate Transporter-1 and the Folate Receptor alpha in Mammalian Retinal Pigment Epithelium
J. Biol. Chem., June 30, 2000; 275(27): 20676 - 20684.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1993 by The American Society for Nutrition