Am J Physiol Cell Physiol Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Cell Physiol 279: C1751-C1759, 2000;
0363-6143/00 $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 ISI Web of Science
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 ISI Web of Science (16)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zhou, X.-B.
Right arrow Articles by Korth, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zhou, X.-B.
Right arrow Articles by Korth, M.
Vol. 279, Issue 6, C1751-C1759, December 2000

BKCa channel activation by membrane-associated cGMP kinase may contribute to uterine quiescence in pregnancy

Xiao-Bo Zhou1, Ge-Xin Wang1, Peter Ruth2, Bernd Hüneke3, and Michael Korth1

1 Abteilung Pharmakologie für Pharmazeuten and 3 Frauenklinik, Universitäts-Krankenhaus Eppendorf, D-20246 Hamburg; and 2 Institut für Pharmakologie und Toxikologie der Technischen Universität München, D-80802 Munich, Germany

We investigated the influence of pregnancy on large-conductance calcium-activated potassium channel (BKCa) activity (NPo) and on channel expression in membranes of isolated human myometrial smooth muscle cells. NPo in inside-out patches was higher in pregnant myometria (PM) compared with nonpregnant myometria (NPM), and the half-maximal activation potential was shifted by 39 mV to more negative potentials. This effect was not due to an enhanced BKCa channel expression. In the presence of cAMP kinase (PKA) or cGMP kinase (PKG), NPo increased in patches from PM but decreased in those from NPM. Western blot analysis and use of a specific PKG inhibitor (1 µM KT-5823) verified the existence of a partially active membrane-associated PKG. Inhibition of PKA by 100 nM PKI, the inhibitory peptide of PKA, had no effect on NPo. 8-p-Chlorophenylthio-cGMP (8-pCPT-cGMP) hyperpolarized cells from PM. This effect was abolished by iberiotoxin, a specific blocker of BKCa channels. It is concluded that an endogenous, membrane-bound PKG in myometrial cells specifically enhances BKCa channel activity during pregnancy and thus may contribute to uterine quiescence during pregnancy.

large-conductance calcium-activated potassium channels; cyclic nucleotide-regulated protein kinases; protein kinase inhibitors; human myometrium; pregnancy maintenance


This article has been cited by other articles:


Home page
 J. Physiol.Home page
A. Shmygol, K. Noble, and S. Wray
Depletion of membrane cholesterol eliminates the Ca2+-activated component of outward potassium current and decreases membrane capacitance in rat uterine myocytes
J. Physiol., June 1, 2007; 581(2): 445 - 456.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
M. R. Keyser and J. L. Witten
Calcium-activated potassium channel of the tobacco hornworm, Manduca sexta: molecular characterization and expression analysis
J. Exp. Biol., November 1, 2005; 208(21): 4167 - 4179.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
S. D. Rybalkin, I. G. Rybalkina, R. Feil, F. Hofmann, and J. A. Beavo
Regulation of cGMP-specific Phosphodiesterase (PDE5) Phosphorylation in Smooth Muscle Cells
J. Biol. Chem., January 25, 2002; 277(5): 3310 - 3317.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
X.-B. Zhou, C. Arntz, S. Kamm, K. Motejlek, U. Sausbier, G.-X. Wang, P. Ruth, and M. Korth
A Molecular Switch for Specific Stimulation of the BKCa Channel by cGMP and cAMP Kinase
J. Biol. Chem., November 9, 2001; 276(46): 43239 - 43245.
[Abstract] [Full Text] [PDF]


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