These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Characterization and regulation of Ca2+-dependent K+ channels in human esophageal smooth muscle.
    Author: Hurley BR, Preiksaitis HG, Sims SM.
    Journal: Am J Physiol; 1999 Apr; 276(4):G843-52. PubMed ID: 10198326.
    Abstract:
    We examined the properties of K+ channels in smooth muscle cells dissociated from human esophagus using patch-clamp recording in the cell-attached configuration. The predominant channel observed had a conductance of 224 +/- 4 pS, and current reversal was dependent on K+ concentration. Channel activity was voltage dependent and increased with elevation of intracellular free Ca2+ concentration ([Ca2+]i), consistent with this being the large-conductance Ca2+-dependent K+ (KCa) channel. ACh as well as caffeine caused transient increases in KCa channel activity, and the effects of ACh persisted in Ca2+-free solution, indicating that Ca2+ release from stores contributed to channel activation. Simultaneous patch clamp and fluorescence revealed that KCa channel activity was well correlated with elevation of [Ca2+]i. The functional role of KCa channels in esophagus was studied by measuring ACh-induced contraction of strips of muscle. Tetraethylammonium and iberiotoxin, blockers of KCa channels, increased ACh-induced contraction, consistent with a role for K+ channels in limiting excitation and contraction. These studies are the first to characterize KCa channels and their regulation in human esophageal smooth muscle.
    [Abstract] [Full Text] [Related] [New Search]