262 MODULATION OF BLADDER AFFERENT SIGNALS IN NORMAL AND SPINAL CORD INJURED RATS BY P2X3 AND P2X2/3 PURINERGIC RECEPTORS

Abstract

You have accessJournal of UrologyBladder and Urethra: Anatomy, Physiology and Pharmacology I1 Apr 2012262 MODULATION OF BLADDER AFFERENT SIGNALS IN NORMAL AND SPINAL CORD INJURED RATS BY P2X3 AND P2X2/3 PURINERGIC RECEPTORS Alvaro Munoz, George Somogyi, Timothy Boone, Anthony Ford, and Christopher Smith Alvaro MunozAlvaro Munoz Houston, TX More articles by this author , George SomogyiGeorge Somogyi Houston, TX More articles by this author , Timothy BooneTimothy Boone Houston, TX More articles by this author , Anthony FordAnthony Ford San Mateo, CA More articles by this author , and Christopher SmithChristopher Smith Houston, TX More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.319AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The neural control of urinary tract function is compromised after spinal cord injury. The objective of this in vivo study was to evaluate the modulatory role of P2X3 and P2X2/3 purinergic receptors on bladder sensory activity using electrophysiologic and cystometric methods in normal (NL) or chronic spinal cord injured (SCI) rats. METHODS SCI was induced in female rats by T8/T9 cord transection and experiments were performed 4 weeks later, when bladder overactivity developed. NL rats were used as controls. Laminectomy was performed at the L1-L2 levels and field potentials were acquired with tungsten microelectrodes in response to noxious intravesical pressure-stimulation (60 cm-water) via a suprapubic catheter. Spinal neural activity was recorded in 1) control conditions; 2) after intravesical stimulation of purinergic receptors with 1mM ATP; and 3) following application of the P2X3/P2X2/3 purinergic antagonist AF-353 (10 mg/kg and 20 mg/kg; i.v.). Open cystometry (CMG) was performed in urethane-anesthetized rats that were intravesically infused with saline (0.1 ml/min). The antagonist AF-353 (10 mg/kg and 20mg/kg; i.v.) was applied after baseline recordings. Changes in the frequency of voiding (VC) and non-voiding (NVC) contractions were evaluated. RESULTS SCI rats exhibited a significantly higher frequency of field potentials following noxious pressure stimulation as well an increased frequency of VC and NVC during cystometric studies. Intravesically applied ATP increased field potential frequency in NL but not in SCI rats, while systemic AF-353 significantly reduced neuronal activity in both groups. In the CMG experiments, AF-353 reduced the frequency of VC in NL but not in SCI rats; however, the frequency of NVC in SCI animals was significantly decreased. CONCLUSIONS These results suggest that P2X3 / P2X2/3 purinergic receptors positively modulate bladder sensory activity and promote the development of NVC in SCI rats. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e106-e107 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Alvaro Munoz Houston, TX More articles by this author George Somogyi Houston, TX More articles by this author Timothy Boone Houston, TX More articles by this author Anthony Ford San Mateo, CA More articles by this author Christopher Smith Houston, TX More articles by this author Expand All Advertisement Advertisement Loading ...