Novel Excitatory Effects of Adenosine Triphosphate on Contractile and Pacemaker Activity in Rabbit Urethral Smooth Muscle
2009; Lippincott Williams & Wilkins; Volume: 183; Issue: 2 Linguagem: Inglês
10.1016/j.juro.2009.09.075
ISSN1527-3792
AutoresEamonn Bradley, Sonia Kadima, Bernard T. Drumm, Mark A. Hollywood, K. D. Thornbury, Noel G. McHale, Gerard P. Sergeant,
Tópico(s)Restless Legs Syndrome Research
ResumoNo AccessJournal of UrologyInvestigative Urology1 Feb 2010Novel Excitatory Effects of Adenosine Triphosphate on Contractile and Pacemaker Activity in Rabbit Urethral Smooth Muscle Eamonn Bradley, Sonia Kadima, Bernard Drumm, Mark A. Hollywood, Keith D. Thornbury, Noel G. McHale, and Gerard P. Sergeant Eamonn BradleyEamonn Bradley , Sonia KadimaSonia Kadima , Bernard DrummBernard Drumm , Mark A. HollywoodMark A. Hollywood , Keith D. ThornburyKeith D. Thornbury , Noel G. McHaleNoel G. McHale , and Gerard P. SergeantGerard P. Sergeant View All Author Informationhttps://doi.org/10.1016/j.juro.2009.09.075AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract Purpose: Adenosine triphosphate is thought to be an important neurotransmitter in urethral smooth muscle but its physiological role is still unclear. We characterized the effects of adenosine triphosphate on contractile and pacemaker activity in rabbit urethral smooth muscle. Materials and Methods: Tension recordings were made from strips of rabbit proximal urethral smooth muscle. Membrane currents from freshly isolated smooth muscle cells and interstitial cells of Cajal were recorded using the patch clamp technique. Intracellular Ca2+ was measured using confocal microscopy. Results: Exogenous application of adenosine triphosphate (10 μM) evoked robust contractions that were inhibited by the type 2 purinergic receptor blocker suramin (100 μM) and the selective type 2 purinergic Y1 receptor antagonist MRS2500 (Tocris Bioscience, Ellisville, Missouri) (100 nM). Application of the type 2 purinergic Y receptor agonist 2-MeSADP (1 μM) mimicked the effects of adenosine triphosphate. When smooth muscle cells were studied under voltage clamp at −60 mV, adenosine triphosphate evoked a large single inward current (greater than 1.2 nA) but 2-MeSADP produced a small current (about 16 pA). In contrast, when interstitial cells of Cajal were held at −60 mV, they showed spontaneous transient inward currents that were increased in frequency by adenosine triphosphate and 2-MeSADP. These excitatory effects were inhibited by suramin and MRS2500. Interstitial cells of Cajal showed spontaneous Ca2+ waves that were increased in frequency by adenosine triphosphate and 2-MeSADP. These effects were also inhibited by suramin and MRS2500. Conclusions: Contractile effects of adenosine triphosphate in urethral smooth muscle are mediated by the activation of type 2 purinergic Y receptors on interstitial cells of Cajal. References 1 : Regulation of tone in pig urethral smooth muscle. J Urol1993; 150: 223. 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Google Scholar Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, County Louth, Ireland© 2010 by American Urological AssociationFiguresReferencesRelatedDetailsCited byBradley E, Kadima S, Kyle B, Hollywood M, Thornbury K, McHale N and Sergeant G (2011) P2X Receptor Currents in Smooth Muscle Cells Contribute to Nerve Mediated Contractions of Rabbit Urethral Smooth MuscleJournal of Urology, VOL. 186, NO. 2, (745-752), Online publication date: 1-Aug-2011. Volume 183Issue 2February 2010Page: 801-811 Advertisement Copyright & Permissions© 2010 by American Urological AssociationKeywordsurethramuscle contractionadenosine triphosphateurinary incontinencesmoothmuscleMetricsAuthor Information Eamonn Bradley More articles by this author Sonia Kadima More articles by this author Bernard Drumm More articles by this author Mark A. Hollywood More articles by this author Keith D. Thornbury More articles by this author Noel G. McHale More articles by this author Gerard P. 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