Document Detail


Openers of SKCa and IKCa channels enhance agonist-evoked endothelial nitric oxide synthesis and arteriolar vasodilation.
MedLine Citation:
PMID:  19074509     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Recent data have led us to hypothesize that selective activation of endothelial small- and/or intermediate-conductance, calcium-activated potassium channels (SK(Ca) and IK(Ca) channels, respectively) by the opener compounds NS309 and DCEBIO would augment stimulated nitric oxide (NO) synthesis and vasodilation in resistance arteries. Experimentally, ATP-evoked changes in membrane potential, cytosolic Ca(2+), and NO synthesis were recorded by patch clamp and microfluorimetry in single human endothelial cells. Agonist-evoked inhibition of myogenic tone in isolated, pressurized arterioles from rat cremaster skeletal muscle was analyzed by video microscopy. NS309 and DCEBIO enhanced ATP-evoked membrane hyperpolarization and cytosolic Ca(2+) transients, along with acute NO synthesis in isolated endothelial cells. The acetylcholine-mediated inhibition of myogenic tone (IC(50)=237 nM) was left-shifted in the presence of NS309 and DCEBIO (10, 100, and 1000 nM) to IC(50) values of 101, 78, and 43 nM; endothelial denudation inhibited this drug effect. L-NAME attenuated the acetylcholine-induced inhibition of myogenic tone but did not interfere with NS309 and DCEBIO-evoked vasodilation. Collectively, our data demonstrate that drug-induced enhancement of endothelial SK(Ca) and IK(Ca) channel activities represents a novel cellular mechanism to increase vasodilation of small-resistance arterioles, thereby highlighting these channels as potential therapeutic targets in cardiovascular disease states associated with compromised NO signaling.
Authors:
Jian-zhong Sheng; Srikanth Ella; Michael J Davis; Michael A Hill; Andrew P Braun
Related Documents :
10666109 - High k(+)-induced membrane depolarization attenuates endothelium-dependent pulmonary va...
9490839 - Regulation of arterial diameter and wall [ca2+] in cerebral arteries of rat by membrane...
8223929 - Endothelium-independent pressor effect of big endothelin-1 and its inhibition by phosph...
18329669 - Endothelium-independent vasodilation effect of di- and tri-peptides in thoracic aorta o...
11380519 - K(ca) channel-opening activity of ginkgo biloba extracts and ginsenosides in cultured e...
9774369 - Calcium channel blockade enhances nitric oxide synthase expression by cultured endothel...
11304499 - Microtubule disruption by colchicine reversibly enhances calcium signaling in intact ra...
7397519 - An analysis of histamine-induced inhibitory response in molluscan neurons.
19927399 - Kcl transport across an insect epithelium: i. tracer fluxes and the effects of ion subs...
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2008-12-12
Journal Detail:
Title:  FASEB journal : official publication of the Federation of American Societies for Experimental Biology     Volume:  23     ISSN:  1530-6860     ISO Abbreviation:  FASEB J.     Publication Date:  2009 Apr 
Date Detail:
Created Date:  2009-04-01     Completed Date:  2009-05-01     Revised Date:  2012-02-15    
Medline Journal Info:
Nlm Unique ID:  8804484     Medline TA:  FASEB J     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1138-45     Citation Subset:  IM    
Affiliation:
Department of Pharmacology and Therapeutics, University of Calgary, Calgary, Alberta, Canada.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acetylcholine / pharmacology
Adenosine Triphosphate / pharmacology
Animals
Arterioles / drug effects,  metabolism
Benzimidazoles / pharmacology*
Calcium / metabolism
Cell Line
Cytosol / metabolism
Dose-Response Relationship, Drug
Endothelial Cells / drug effects,  metabolism
Ethylamines / metabolism
Fluoresceins / metabolism
Fluorometry
Humans
Indoles / pharmacology*
Inhibitory Concentration 50
Male
Membrane Potentials / drug effects
NG-Nitroarginine Methyl Ester / pharmacology
Nitric Oxide / biosynthesis*
Oximes / pharmacology*
Patch-Clamp Techniques
Potassium Channels, Calcium-Activated / agonists,  metabolism*
Rats
Small-Conductance Calcium-Activated Potassium Channels / agonists,  metabolism*
Vasodilation / drug effects*,  physiology
Grant Support
ID/Acronym/Agency:
NHLBI-71796//PHS HHS
Chemical
Reg. No./Substance:
0/3-amino-4-monomethylamino-2',7'-difluorofluorecein; 0/5,6-dichloro-1-ethyl-1,3-dihydro-2H-benzimidazol-2-one; 0/6,7-dichloro-1H-indole-2,3-dione 3-oxime; 0/Benzimidazoles; 0/Ethylamines; 0/Fluoresceins; 0/Indoles; 0/Oximes; 0/Potassium Channels, Calcium-Activated; 0/Small-Conductance Calcium-Activated Potassium Channels; 10102-43-9/Nitric Oxide; 50903-99-6/NG-Nitroarginine Methyl Ester; 51-84-3/Acetylcholine; 56-65-5/Adenosine Triphosphate; 7440-70-2/Calcium
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Alzheimer disease specific phosphoepitopes of Tau interfere with assembly of tubulin but not binding...
Next Document:  Duox maturation factors form cell surface complexes with Duox affecting the specificity of reactive ...