Document Detail


Single-channel biophysical and pharmacological characterizations of native human large-conductance calcium-activated potassium channels in freshly isolated detrusor smooth muscle cells.
MedLine Citation:
PMID:  23344746     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
Recent studies have demonstrated the importance of large-conductance Ca(2+)-activated K(+) (BK) channels in detrusor smooth muscle (DSM) function in vitro and in vivo. However, in-depth characterization of human native DSM single BK channels has not yet been provided. Here, we conducted single-channel recordings from excised patches from native human DSM cells. Inside-out and outside-out recordings in high K(+) symmetrical solution (containing 140 mM KCl and ~300 nM free Ca(2+)) showed single-channel conductance of 215-220 pS, half-maximum constant for activation of ~+75 to +80 mV, and low probability of opening (P (o)) at +20 mV that increased ~10-fold at +40 mV and ~60-fold at +60 mV. Using the inside-out configuration at +30 mV, reduction of intracellular [Ca(2+)] from ~300 nM to Ca(2+)-free decreased the P (o) by ~85 %, whereas elevation to ~800 nM increased P (o) by ~50-fold. The BK channel activator NS1619 (10 μM) enhanced the P (o) by ~10-fold at +30 mV; subsequent application of the selective BK channel inhibitor paxilline (500 nM) blocked the activity. Changes in intracellular [Ca(2+)] or the addition of NS1619 did not significantly alter the current amplitude or single-channel conductance. This is the first report to provide biophysical and pharmacological profiles of native human DSM single BK channels highlighting their importance in regulating human DSM excitability.
Authors:
John Malysz; Eric S Rovner; Georgi V Petkov
Related Documents :
9103516 - Uptake and release of [3h]formycin b via sodium-dependent nucleoside transporters in mo...
9441706 - Sodium-calcium exchanger in cultured human retinal pigment epithelium.
8387506 - Evidence for involvement of the voltage-dependent na+ channel gating in depolarization-...
19592486 - Synthesis, solution structure, and phylum selectivity of a spider delta-toxin that slow...
17434266 - Effects of extracellular ph on neuronal calcium channel activation.
9739996 - A novel na+/ca2+ channel blocker ns-7 inhibits evoked but not spontaneous dopamine rele...
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2013-1-24
Journal Detail:
Title:  Pflugers Archiv : European journal of physiology     Volume:  -     ISSN:  1432-2013     ISO Abbreviation:  Pflugers Arch.     Publication Date:  2013 Jan 
Date Detail:
Created Date:  2013-1-24     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0154720     Medline TA:  Pflugers Arch     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
Department of Pharmaceutical and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Coker Life Sciences Building, Room 609D, 715 Sumter St., Columbia, SC, 29208, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

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


Previous Document:  Reversible myoclonus in a patient undergoing transcervical hysteroscopic surgery.
Next Document:  Aortic Valve Regurgitation and Ventricular Septal Defect Diagnosed 5 Years after Penetrating Cardiac...