Type

Other / n/a

Authors

Noel G McHale
Brian J Harvey
Akemichi Baba
Toshio T Matsuda
Keith T Thornbury
Mark A Hollywood
Gerard P Sergeant
Bernard T Drumm

Subjects

Pharmacology

Topics
medical sciences medical molecular biology smooth muscle cells interstitial cell of cajal smooth muscle calcium oscillations interstitial cells of cajal sodium calcium exchange

The effect of high [K(+)]o on spontaneous Ca(2+) waves in freshly isolated interstitial cells of Cajal from the rabbit urethra. (2014)

Abstract Interstitial cells of Cajal (ICC) act as putative pacemaker cells in the rabbit urethra. Pacemaker activity in ICC results from spontaneous global Ca(2+) waves that can be increased in frequency by raising external [K(+)]. The purpose of this study was to elucidate the mechanism of this response. Intracellular [Ca(2+)] was measured in fluo-4-loaded smooth muscle cells (SMCs) and ICC using a Nipkow spinning disk confocal microscope. Increasing [K(+)]o to 60 mmol/L caused an increase in [Ca(2+)]i accompanied by contraction in SMCs. Raising [K(+)]o did not cause contraction in ICC, but the frequency of firing of spontaneous calcium waves increased. Reducing [Ca(2+)]o to 0 mmol/L abolished the response in both cell types. Nifedipine of 1 μmol/L blocked the response of SMC to high [K(+)]o, but did not affect the increase in firing in ICC. This latter effect was blocked by 30 μmol/L NiCl2 but not by the T-type Ca(2+) channel blocker mibefradil (300 nmol/L). However, inhibition of Ca(2+) influx via reverse-mode sodium/calcium exchange (NCX) using either 1 μmol/L SEA0400 or 5 μmol/L KB-R7943 did block the effect of high [K(+)]o on ICC. These data suggest that high K(+) solution increases the frequency of calcium waves in ICC by increasing Ca(2+) influx through reverse-mode NCX.
Collections Ireland -> Royal College of Surgeons in Ireland -> Molecular Medicine Articles
Ireland -> Royal College of Surgeons in Ireland -> Department of Molecular Medicine

Full list of authors on original publication

Noel G McHale, Brian J Harvey, Akemichi Baba, Toshio T Matsuda, Keith T Thornbury, Mark A Hollywood, Gerard P Sergeant, Bernard T Drumm

Experts in our system

1
Noel G McHale
Dundalk IT
Total Publications: 35
 
2
Brian J Harvey
Royal College of Surgeons in Ireland
Total Publications: 102
 
3
Mark A Hollywood
Dundalk IT
Total Publications: 35
 
4
Gerard P Sergeant
Dundalk IT
Total Publications: 24
 
5
Bernard T Drumm
Royal College of Surgeons in Ireland
Total Publications: 5