AJP - Renal AJP: Lung Cellular and Molecular Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Renal Physiol 249: F497-F506, 1985;
0363-6127/85 $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 Renfro, J. L.
Right arrow Articles by Shustock, E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Renfro, J. L.
Right arrow Articles by Shustock, E.

AJP - Renal Physiology, Vol 249, Issue 4 497-F506, Copyright © 1985 by American Physiological Society

ARTICLES

Peritubular uptake and brush border transport of 28Mg by flounder renal tubules

J. L. Renfro and E. Shustock

The uptake of 28Mg by isolated renal tubules of winter flounder, Pseudopleuronectes americanus, was studied by compartmental analysis. Two phases of uptake were seen in steady-state conditions. The slow-exchanging compartment was 46% of the total Mg content, and uptake into this compartment was saturable (Km = 0.36 mM) and inhibited by 10 mM CaCl2, dinitrophenol, and ouabain but not by furosemide, Na-free medium, or cytochalasin B. The fast-exchanging compartment was 5% of the total Mg, and uptake into this compartment showed sigmoid saturation kinetics (K 1/2 = 1.62 mM). The fast uptake rate was inhibited by dinitrophenol, ouabain, Na-free medium, 10 mM CaCl2, and furosemide but stimulated by cytochalasin B. 28Mg efflux from brush border membrane vesicles (BBMV) was stimulated by both an inside positive electrical potential generated by 100 mM KCl (out greater than in, in the presence of valinomycin) and by 100 mM NaCl (out greater than in). The latter effect was still present when the membrane electrical potential was short-circuited with 100 mM KCl (in = out) in the presence of valinomycin. Uptake of Mg by BBMV was stimulated by reversal of the aforementioned gradients. Both uptake and efflux were stimulated by A23187. BBMV uptake was inhibited by 10 mM CaCl2 and unaffected by furosemide. The relationship of electrical gradient-driven and Na gradient-driven Mg transport to the Mg secretory function of these tubules is discussed.


This article has been cited by other articles:


Home page
 Am. J. Physiol. Renal Physiol.Home page
K. W. Beyenbach
Kidneys sans glomeruli
Am J Physiol Renal Physiol, May 1, 2004; 286(5): F811 - F827.
[Abstract] [Full Text] [PDF]


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