Am J Physiol Cell Physiol Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Cell Physiol 254: C773-C780, 1988;
0363-6143/88 $5.00
This Article
Right arrow Full Text (PDF)
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 Email this article to a friend
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
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Johnson, L. W.
Right arrow Articles by Smith, C. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Johnson, L. W.
Right arrow Articles by Smith, C. H.

AJP - Cell Physiology, Vol 254, Issue 6 C773-C780, Copyright © 1988 by American Physiological Society

ARTICLES

Neutral amino acid transport systems of microvillous membrane of human placenta

L. W. Johnson and C. H. Smith
Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, Children's Hospital, St. Louis, Missouri 63110.

Placental transport produces concentrations of amino acids in fetal blood greater than those of maternal blood. Competitive inhibition studies of zwitterionic amino acid transport in isolated vesicles from the microvillous (maternal facing) plasma membranes of syncytiotrophoblast defined three transport systems: 1) a sodium-dependent system that supports methylaminoisobutyric acid (MeAIB) transport and has the characteristics of an A system; 2) a sodium-independent system with a high affinity for leucine and other amino acids with branched or aromatic side chains; and 3) a sodium-independent system with a preference for alanine as a substrate. The two sodium-independent systems could be further discriminated by marked specificity for trans stimulation with alanine or with leucine. System ASC, known to be present in whole placenta, and the neutral brush-border or imino systems of other polarized epithelia were apparently absent. Kinetic characteristics of the A system make it the probable primary driving force for concentrative transfer of its substrate amino acids to the fetus. Characteristics of the high-affinity leucine system demonstrated that it is saturated by normal serum leucine concentrations. Regulation of either system has the potential to alter placental amino acid uptake and transfer to the fetus.


This article has been cited by other articles:


Home page
 J. Physiol.Home page
M. Desforges, K. J. Mynett, R. L. Jones, S. L. Greenwood, M. Westwood, C. P. Sibley, and J. D. Glazier
The SNAT4 isoform of the system A amino acid transporter is functional in human placental microvillous plasma membrane
J. Physiol., January 1, 2009; 587(1): 61 - 72.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
E. Shibata, R. W. Powers, A. Rajakumar, F. von Versen-Hoynck, M. J. Gallaher, D. L. Lykins, J. M. Roberts, and C. A. Hubel
Angiotensin II decreases system A amino acid transporter activity in human placental villous fragments through AT1 receptor activation
Am J Physiol Endocrinol Metab, November 1, 2006; 291(5): E1009 - E1016.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
M. Desforges, H. A. Lacey, J. D. Glazier, S. L. Greenwood, K. J. Mynett, P. F. Speake, and C. P. Sibley
SNAT4 isoform of system A amino acid transporter is expressed in human placenta
Am J Physiol Cell Physiol, January 1, 2006; 290(1): C305 - C312.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
A. Ericsson, B. Hamark, N. Jansson, B. R. Johansson, T. L. Powell, and T. Jansson
Hormonal regulation of glucose and system A amino acid transport in first trimester placental villous fragments
Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2005; 288(3): R656 - R662.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
E. E. Champion, S. J. Mann, J. D. Glazier, C. J. P. Jones, J. M. Rawlings, C. P. Sibley, and S. L. Greenwood
System {beta} and System A amino acid transporters in the feline endotheliochorial placenta
Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2004; 287(6): R1369 - R1379.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
D. M. Nelson, S. D. Smith, T. C. Furesz, Y. Sadovsky, V. Ganapathy, C. A. Parvin, and C. H. Smith
Hypoxia reduces expression and function of system A amino acid transporters in cultured term human trophoblasts
Am J Physiol Cell Physiol, February 1, 2003; 284(2): C310 - C315.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
Y. Okamoto, M. Sakata, K. Ogura, T. Yamamoto, M. Yamaguchi, K. Tasaka, H. Kurachi, M. Tsurudome, and Y. Murata
Expression and regulation of 4F2hc and hLAT1 in human trophoblasts
Am J Physiol Cell Physiol, January 1, 2002; 282(1): C196 - C204.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
M. Johansson, T. Jansson, and T. L. Powell
Na+-K+-ATPase is distributed to microvillous and basal membrane of the syncytiotrophoblast in human placenta
Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2000; 279(1): R287 - R294.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online