AJP - Lung Columbus Instruments
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Lung Cell Mol Physiol 269: L137-L143, 1995;
1040-0605/95 $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
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 Meredith, D.
Right arrow Articles by Boyd, C. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Meredith, D.
Right arrow Articles by Boyd, C. A.

AJP - Lung Cellular and Molecular Physiology, Vol 269, Issue 2 137-L143, Copyright © 1995 by American Physiological Society

ARTICLES

Dipeptide transport characteristics of the apical membrane of rat lung type II pneumocytes

D. Meredith and C. A. Boyd
Department of Human Anatomy, University of Oxford, United Kingdom.

The transport of a hydrolysis-resistant dipeptide, D-phenylalanyl-L-alanine (D-Phe-L-Ala), has been studied by high-performance liquid chromatography in rat lung epithelial cells and apical membrane vesicles. Time-dependent uptake of D-Phe-L-Ala into isolated type II pneumocytes was shown. Uptake was saturable, and Michaelis-Menten kinetics were fitted to the data and gave an apparent Michaelis constant (Km) of 3.4 mM and a maximum velocity (Vmax) of 7.0 nmol.mg protein-1.min-1. However, known peptide transport inhibitors unexpectedly increased intracellular D-Phe-L-Ala concentration when initial rates of peptide uptake were studied. Apical (brush-border) membrane vesicles prepared from rat lung also showed time- and concentration-dependent influx of D-Phe-L-Ala (apparent Km 2.0 mM, Vmax 0.53 nmol.mg protein-1.min-1). Influx of this neutral dipeptide into the vesicles was shown to be both electrogenic and stimulated by an inwardly directed proton gradient. Influx was inhibitable by mercuric chloride and by the amino acid residue modifying compounds N-acetylimidazole and diethylpyrocarbonate. These findings strongly suggest the presence of a proton-coupled peptide transport protein in the apical surface of the type II cell. This transporter may play a role in lung homeostasis.


This article has been cited by other articles:


Home page
 ThoraxHome page
D A Groneberg, P R Eynott, F Doring, Q Thai Dinh, T Oates, P J Barnes, K F Chung, H Daniel, and A Fischer
Distribution and function of the peptide transporter PEPT2 in normal and cystic fibrosis human lung
Thorax, January 1, 2002; 57(1): 55 - 60.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Pathol.Home page
D. A. Groneberg, M. Nickolaus, J. Springer, F. Doring, H. Daniel, and A. Fischer
Localization of the Peptide Transporter PEPT2 in the Lung : Implications for Pulmonary Oligopeptide Uptake
Am. J. Pathol., February 1, 2001; 158(2): 707 - 714.
[Abstract] [Full Text] [PDF]

Home page
 J. Pharmacol. Exp. Ther.Home page
K. Takahashi, N. Nakamura, T. Terada, T. Okano, T. Futami, H. Saito, and K.-I. Inui
Interaction of beta -Lactam Antibiotics with H+/Peptide Cotransporters in Rat Renal Brush-Border Membranes
J. Pharmacol. Exp. Ther., August 1, 1998; 286(2): 1037 - 1042.
[Abstract] [Full Text]


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