AJP - Renal Information on EB 2010
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Renal Physiol 276: F72-F78, 1999;
0363-6127/99 $5.00
This Article
Right arrow Full Text
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 Arar, M.
Right arrow Articles by Levi, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Arar, M.
Right arrow Articles by Levi, M.
Vol. 276, Issue 1, F72-F78, January 1999

Epidermal growth factor inhibits Na-Pi cotransport in weaned and suckling rats

Mazen Arar1, Hubert K. Zajicek2, Ihsan Elshihabi1
Moshe Levi2
(With the Technical Assistance of Myrna Gonzales and Paul Wilson)

1 Department of Pediatrics, University of Texas Health Science Center at San Antonio, San Antonio 78284; and 2 Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas and Veterans Affairs Medical Center, Dallas, Texas 75216

In the present study, we determined the effect of epidermal growth factor (EGF; 10 µg/100 g body wt) on sodium gradient-dependent phosphate transport (Na-Pi cotransport) regulation in suckling (12-day-old) and weaned (24-day-old) rats. Weaned rats had higher proximal tubular brush border membrane vesicle (BBMV) Na-Pi cotransport activity (232 ± 16 in weaned vs. 130 ± 9 pmol · 10 s-1 · mg protein-1 in suckling rats, P < 0.05). Chronic treatment with EGF induced inhibition of BBMV Na-Pi cotransport in both suckling (130 ± 9 vs. 104 ± 7 pmol · 10 s-1 · mg protein-1, P < 0.05) and weaned rats (232 ± 16 vs. 145 ± 9 pmol · 10 s-1 · mg protein-1, P < 0.005). The inhibitory effect was selective for Na-Pi cotransport as there was no inhibition of Na-glucose cotransport. Weaned rats had a higher abundance of BBMV NaPi-2 protein than suckling rats (increase of 54%, P < 0.001) and a twofold increase in NaPi-2 mRNA. The EGF-induced inhibition of Na-Pi transport was paralleled by decreases in NaPi-2 protein abundance in both weaned (decrease of 26%, P < 0.01) and suckling (decrease of 27%, P < 0.01) animals. In contrast, there were no changes in NaPi-2 mRNA abundance. We conclude that proximal tubule BBMV Na-Pi cotransport activity, NaPi-2 protein abundance, and NaPi-2 mRNA abundance are higher in weaned than in suckling rats. EGF inhibits Na-Pi cotransport activity in BBMV isolated from suckling and weaned rats, and this inhibition is mediated via a decrease in NaPi-2 protein abundance, in the absence of a change in NaPi-2 mRNA.

NaPi-2 mRNA; NaPi-2 protein; phosphate transporter maturation


This article has been cited by other articles:


Home page
 Am. J. Physiol. Renal Physiol.Home page
S. Y. Breusegem, N. Halaihel, M. Inoue, H. Zajicek, E. Lederer, N. P. Barry, V. Sorribas, and M. Levi
Acute and chronic changes in cholesterol modulate Na-Pi cotransport activity in OK cells
Am J Physiol Renal Physiol, July 1, 2005; 289(1): F154 - F165.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
H. Xu, M. Inouye, E. R. Hines, J. F. Collins, and F. K. Ghishan
Transcriptional regulation of the human NaPi-IIb cotransporter by EGF in Caco-2 cells involves c-myb
Am J Physiol Cell Physiol, May 1, 2003; 284(5): C1262 - C1271.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Gastrointest. Liver Physiol.Home page
K. Arima, E. R. Hines, P. R. Kiela, J. B. Drees, J. F. Collins, and F. K. Ghishan
Glucocorticoid regulation and glycosylation of mouse intestinal type IIb Na-Pi cotransporter during ontogeny
Am J Physiol Gastrointest Liver Physiol, August 1, 2002; 283(2): G426 - G434.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
H. Segawa, I. Kaneko, A. Takahashi, M. Kuwahata, M. Ito, I. Ohkido, S. Tatsumi, and K.-i. Miyamoto
Growth-related Renal Type II Na/Pi Cotransporter
J. Biol. Chem., May 24, 2002; 277(22): 19665 - 19672.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
H. Xu, J. F. Collins, L. Bai, P. R. Kiela, and F. K. Ghishan
Regulation of the human sodium-phosphate cotransporter NaPi-IIb gene promoter by epidermal growth factor
Am J Physiol Cell Physiol, March 1, 2001; 280(3): C628 - C636.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. Rev.Home page
H. Murer, N. Hernando, I. Forster, and J. Biber
Proximal Tubular Phosphate Reabsorption: Molecular Mechanisms
Physiol Rev, October 1, 2000; 80(4): 1373 - 1409.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
Y. S. Guner, P. R. Kiela, H. Xu, J. F. Collins, and F. K. Ghishan
Differential regulation of renal sodium-phosphate transporter by glucocorticoids during rat ontogeny
Am J Physiol Cell Physiol, November 1, 1999; 277(5): C884 - C890.
[Abstract] [Full Text] [PDF]


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