Am J Physiol Cell Physiol AJP citation statistics
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Cell Physiol 268: C1026-C1032, 1995;
0363-6143/95 $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
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 Dunham, P. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Dunham, P. B.

AJP - Cell Physiology, Vol 268, Issue 4 C1026-C1032, Copyright © 1995 by American Physiological Society

ARTICLES

Effects of urea on K-Cl cotransport in sheep red blood cells: evidence for two signals of swelling

P. B. Dunham
Department of Biology, Syracuse University, New York 13244, USA.

The activation proceeds with a delay, like activation by swelling. Swelling of cells in urea activates K uptake further, but with no delay. Inactivation after removal of urea also proceeds without delay. With cotransport partially activated by reducing intracellular Mg concentration ([Mg]i) or with staurosporine, urea did not activate cotransport further. However, swelling activated cotransport further in these two types of cells. In terms of the three-state process for swelling-activation of K-Cl cotransport (P. B. Dunham, J. Klimczak, and P. J. Logue, J. Gen. Physiol. 101: 733-765, 1993), these results indicate that urea activates the first conversion, A-->B, and does so by inhibiting the reverse reaction promoted by a kinase, just as reducing [Mg]i does. Stimulation of cotransport by urea is nearly completely reversed by shrinkage, whereas activation by reducing [Mg]i is reversed only approximately 35%. Therefore urea inhibits the kinase indirectly, like swelling, by reducing macromolecular crowding of cytoplasmic proteins (A. P. Minton, G. C. Coleclasure, and J. C. Parker. Proc. Natl. Acad. Sci. USA 89: 10504-10506, 1992). Since swelling activates cotransport in two ways, one mimicked by urea and one not, there must be two signals of swelling, one a reduction of macromolecular crowding and the other probably a mechanical signal.


This article has been cited by other articles:


Home page
 Physiol. Rev.Home page
E. K. Hoffmann, I. H. Lambert, and S. F. Pedersen
Physiology of Cell Volume Regulation in Vertebrates
Physiol Rev, January 1, 2009; 89(1): 193 - 277.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
I. Bize, S. Taher, and C. Brugnara
Regulation of K-Cl cotransport during reticulocyte maturation and erythrocyte aging in normal and sickle erythrocytes
Am J Physiol Cell Physiol, July 1, 2003; 285(1): C31 - C38.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
H. Liapis, M. Nag, and D. M. Kaji
K-Cl cotransporter expression in the human kidney
Am J Physiol Cell Physiol, December 1, 1998; 275(6): C1432 - C1437.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
T. Krarup, L. D. Jakobsen, B. S. Jensen, and E. K. Hoffmann
Na+-K+-2Cl- cotransport in Ehrlich cells: regulation by protein phosphatases and kinases
Am J Physiol Cell Physiol, July 1, 1998; 275(1): C239 - C250.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. Rev.Home page
F. LANG, G. L. BUSCH, M. RITTER, H. VOLKL, S. WALDEGGER, E. GULBINS, and D. HAUSSINGER
Functional Significance of Cell Volume Regulatory Mechanisms
Physiol Rev, January 1, 1998; 78(1): 247 - 306.
[Abstract] [Full Text] [PDF]


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