Am J Physiol Cell Physiol Add DOIs to your references at manuscript stage!
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Cell Physiol 274: C983-C991, 1998;
0363-6143/98 $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 Romero, F.
Right arrow Articles by Aboulafia, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Romero, F.
Right arrow Articles by Aboulafia, J.
Vol. 274, Issue 4, C983-C991, April 1998

Activation of Ca2+-activated K+ (maxi-K+) channel by angiotensin II in myocytes of the guinea pig ileum

Fernando Romero, Bagnólia A. Silva, Viviane L. A. Nouailhetas, and Jeannine Aboulafia

Department of Biophysics, Universidade Federal de São Paulo, Escola Paulista de Medicina, 04023-062 São Paulo SP, Brazil

We investigated the regulation of the Ca2+-activated K+ (maxi-K+) channel by angiotensin II (ANG II) and its synthetic analog, [Lys2]ANG II, in freshly dispersed intestinal myocytes. We identified a maxi-K+ channel population in the inside-out patch configuration on the basis of its conductance (257 ± 4 pS in symmetrical 150 mM KCl solution), voltage and Ca2+ dependence of channel opening, low Na+-to-K+ and Cl--to-K+ permeability ratios, and blockade by external Cs+ and tetraethylammonium chloride. ANG II and [Lys2]ANG II caused an indirect, reversible, Ca2+- and dose-dependent activation of maxi-K+ channels in cell-attached experiments when cells were bathed in high-K+ solution. This effect was reversibly blocked by DUP-753, being that it is mediated by the AT1 receptor. Evidences that activation of the maxi-K+ channel by ANG II requires a rise in intracellular Ca2+ concentration ([Ca2+]i) as an intermediate step were the shift of the open probability of the channel-membrane potential relationship to less positive membrane potentials and the sustained increase in [Ca2+]i in fura 2-loaded myocytes. The preservation of the pharmacomechanical coupling of ANG II in these cells provides a good model for the study of transmembrane signaling responses to ANG II and analogs in this tissue.

longitudinal layer; patch clamp; intracellular calcium concentration; fura 2


This article has been cited by other articles:


Home page
 Br. J. Ophthalmol.Home page
A B Cullinane, P S Leung, J Ortego, M Coca-Prados, and B J Harvey
Renin-angiotensin system expression and secretory function in cultured human ciliary body non-pigmented epithelium
Br. J. Ophthalmol., June 1, 2002; 86(6): 676 - 683.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Gastrointest. Liver Physiol.Home page
Y. Hosoda, A. Winarto, T. Iwanaga, and A. Kuwahara
Mode of action of ANG II on ion transport in guinea pig distal colon
Am J Physiol Gastrointest Liver Physiol, April 1, 2000; 278(4): G625 - G634.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
B. A. Silva, V. L. A. Nouailhetas, and J. Aboulafia
Desensitization to ANG II in guinea pig ileum depends on membrane repolarization: role of maxi-K+ channel
Am J Physiol Cell Physiol, October 1, 1999; 277(4): C739 - C745.
[Abstract] [Full Text] [PDF]


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