Pacemaker activity in urethral interstitial cells is not dependent on capacitative calcium entry.

Bradley, Eamonn and Hollywood, Mark A. and McHale, Noel G. and Thornbury, Keith D. and Sergeant, Gerard P. (2005) Pacemaker activity in urethral interstitial cells is not dependent on capacitative calcium entry. Am J Physiol Cell Physiol., 289 (3). pp. 625-632.

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The aim of the present study was to investigate the properties and role of capacitative Ca(2+) entry (CCE) in interstitial cells (IC) isolated from the rabbit urethra. Ca(2+) entry in IC was larger in cells with depleted intracellular Ca(2+) stores compared with controls, consistent with influx via a CCE pathway. The nonselective Ca(2+) entry blockers Gd(3+) (10 microM), La(3+) (10 microM), and Ni(2+) (100 microM) reduced CCE by 67% (n = 14), 65% (n = 11), and 55% (n = 9), respectively. These agents did not inhibit Ca(2+) entry when stores were not depleted. Conversely, CCE in IC was resistant to SKF-96365 (10 microM), wortmannin (10 microM), and nifedipine (1 microM). Spontaneous transient inward currents were recorded from IC voltage-clamped at -60 mV. These events were not significantly affected by Gd(3+) (10 microM) or La(3+) (10 microM) and were only slightly decreased in amplitude by 100 microM Ni(2+). The results from this study demonstrate that freshly dispersed IC from the rabbit urethra possess a CCE pathway. However, influx via this pathway does not appear to contribute to spontaneous activity in these cells.

Item Type: Article
Uncontrolled Keywords: Interstitial cells; Animals; Biological Clocks/physiology; Calcium/metabolism; Calcium Channel Blockers/pharmacology; Female; Gadolinium/pharmacology; Imidazoles/pharmacology; Lanthanum/pharmacology; Male; Membrane Potentials/drug effects; Membrane Potentials/physiology; Myocytes; Smooth Muscle/physiology; Nickel/pharmacology; Patch-Clamp Techniques; Rabbits; Urethra/cytology; Urethra/physiology
Subjects: Science
Research Centres: Smooth Muscle Research Centre
Depositing User: Concepta Woods
Date Deposited: 07 Mar 2012 10:00
Last Modified: 11 Nov 2014 16:10

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