Calcium oscillations in interstitial cells of the rabbit urethra

Johnston, Louise and Sergeant, Gerard P. and Hollywood, Mark A. and McHale, Noel G. (2005) Calcium oscillations in interstitial cells of the rabbit urethra. J Physiol, 565 (2). pp. 449-461.

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Abstract

Measurements were made (using fast confocal microscopy) of intracellular Ca2+ levels in fluo-4 loaded interstitial cells isolated from the rabbit urethra. These cells exhibited regular Ca2+ oscillations which were associated with spontaneous transient inward currents recorded under voltage clamp. Interference with D-myo-inositol 1,4,5-trisphosphate (IP3) induced Ca2+ release using 100 microm 2-aminoethoxydiphenyl borate, and the phospholipase C (PLC) inhibitors 2-nitro-4-carboxyphenyl N,N-diphenylcarbamate and U73122 decreased the amplitude of spontaneous oscillations but did not abolish them. However, oscillations were abolished when ryanodine receptors were blocked with tetracaine or ryanodine. Oscillations ceased in the absence of external Ca2+, and frequency was directly proportional to the external Ca2+ concentration. Frequency of Ca2+ oscillation was reduced by SKF-96365, but not by nifedipine. Lanthanum and cadmium completely blocked oscillations. These results suggest that Ca2+ oscillations in isolated rabbit urethral interstitial cells are initiated by Ca2+ release from ryanodine-sensitive intracellular stores, that oscillation frequency is very sensitive to the external Ca2+ concentration and that conversion of the primary oscillation to a propagated Ca2+ wave depends upon IP3-induced Ca2+ release.

Item Type:	Article
Uncontrolled Keywords:	Interstitial cells; Calcium; Anesthetics; Local/pharmacology; Animals; Boron Compounds/pharmacology; Calcium/pharmacokinetics; Calcium Channels/metabolism; Calcium Signaling/drug effects; Calcium Signaling/physiology; Estrenes/pharmacology; Female; Inositol 1,4,5-Trisphosphate Receptors; Male; Membrane Potentials/drug effects; Membrane Potentials/physiology; Patch-Clamp Techniques; Phosphodiesterase Inhibitors/pharmacology; Pyrrolidinones/pharmacology; Rabbits; Receptors; Cytoplasmic and Nuclear/antagonists & inhibitors; Cytoplasmic and Nuclear/metabolism; Ryanodine/pharmacology; Ryanodine Receptor Calcium Release Channel/metabolism; Tetracaine/pharmacology; Type C Phospholipases/antagonists & inhibitors; Type C Phospholipases/metabolism; Urethra/cytology; Urethra/physiology; Smooth muscle
Subjects:	Science
Research Centres:	Smooth Muscle Research Centre
Depositing User:	Concepta Woods
Date Deposited:	07 Mar 2012 10:11
Last Modified:	11 Nov 2014 16:10
URI:	https://eprints.dkit.ie/id/eprint/190

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