BKCachannel activation by membrane-associated cGMP kinase may contribute to uterine quiescence in pregnancy
| Autor: | Michael Korth, Xiaobo Zhou, Ge-Xin Wang, Bernd Hüneke, Peter Ruth |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
medicine.medical_specialty
Indoles Patch-Clamp Techniques Potassium Channels Physiology Carbazoles In Vitro Techniques Biology Membrane Potentials Uterine contraction Potassium Channels Calcium-Activated Uterine Contraction Alkaloids Obstetric Labor Premature Pregnancy Internal medicine Cyclic GMP-Dependent Protein Kinases medicine Humans Large-Conductance Calcium-Activated Potassium Channels Patch clamp Enzyme Inhibitors Cyclic GMP Protein kinase C Cell Membrane Myometrium Cell Biology Thionucleotides Iberiotoxin Cyclic AMP-Dependent Protein Kinases Potassium channel Endocrinology Platelet aggregation inhibitor Female medicine.symptom Peptides cGMP-dependent protein kinase Platelet Aggregation Inhibitors |
| Zdroj: | American Journal of Physiology-Cell Physiology. 279:C1751-C1759 |
| ISSN: | 1522-1563 0363-6143 |
| DOI: | 10.1152/ajpcell.2000.279.6.c1751 |
| Popis: | 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. NPoin 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 BKCachannel expression. In the presence of cAMP kinase (PKA) or cGMP kinase (PKG), NPoincreased 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 BKCachannels. It is concluded that an endogenous, membrane-bound PKG in myometrial cells specifically enhances BKCachannel activity during pregnancy and thus may contribute to uterine quiescence during pregnancy. |
| Databáze: | OpenAIRE |
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