Induction of Bladder Sphincter Dyssynergia By κ-2 Opioid Receptor Agonists in the Female Rat
2004; Lippincott Williams & Wilkins; Volume: 171; Issue: 1 Linguagem: Inglês
10.1097/01.ju.0000092069.00376.5c
ISSN1527-3792
AutoresBaojun Gu, Matthew O. Fraser, Karl B. Thor, Paul C. Dolber,
Tópico(s)Pelvic floor disorders treatments
ResumoNo AccessJournal of UrologyINVESTIGATIVE UROLOGY1 Jan 2004Induction of Bladder Sphincter Dyssynergia By κ-2 Opioid Receptor Agonists in the Female Rat BAOJUN GU, MATTHEW O. FRASER, KARL B. THOR, and PAUL C. DOLBER BAOJUN GUBAOJUN GU More articles by this author , MATTHEW O. FRASERMATTHEW O. FRASER Financial interest and/or other relationship with Dynogen Pharmaceuticals. More articles by this author , KARL B. THORKARL B. THOR More articles by this author , and PAUL C. DOLBERPAUL C. DOLBER More articles by this author View All Author Informationhttps://doi.org/10.1097/01.ju.0000092069.00376.5cAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract Purpose: The nonselective κ opioid receptor agonist ethylketocyclazocine suppresses external urethral sphincter (EUS) reflexes in cats. We examined the role of spinal κ-opioid receptor subtypes in the control of EUS function in rats using selective κ-1 (U-50,488) or κ-2 (GR-89,696) opiate receptor agonists. Materials and Methods: Urethane anesthetized female rats were catheterized through the bladder dome for cystometry. EUS function was assessed electromyographically. Drugs were administered intrathecally or intravenously. Results: Micturition in rats is accompanied at different times by tonic (continuous) EUS spike activity and by phasic bursts of spikes separated by pauses. GR-89,696 (0.05 to 5 μg intrathecally) caused a dose dependent decrease in the number of bursts per micturition without affecting spike frequency within individual bursts or during periods of tonic activity. It resulted in decreased voiding efficiency and at high doses dyssynergia and overflow incontinence. The nonselective opiate receptor antagonist naloxone (1 mg/kg intravenously) blocked GR-89,696 effects. U-50,488H (0.05 to 15 μg intrathecally) caused no change in cystometric parameters or in EUS-electromyography. Conclusions: Efficient voiding in rats depends on a spinal pattern generator causing EUS motor neuron firing to occur in bursts, resulting in rapid urethral contraction and relaxation. Intrathecal κ-2-opiate receptor agonists suppress this pattern generator, decreasing the number of bursts occurring during each micturition without decreasing motor neuron spike frequency during individual bursts or during tonic spike activity associated with urethral closure. Resultant dyssynergia leads to decreased voiding efficiency. The relevance of κ-2 opioid receptors should be explored in higher species, especially regarding spinal cord injury induced dyssynergia. References 1 : The immunohistochemical localization of nine peptides in the sacral parasympathetic nucleus and the dorsal gray commissure in rat spinal cord. Neuroscience1984; 12: 855. 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(MOF, KBT), Morrisville, North Carolina© 2004 by American Urological Association, Inc.FiguresReferencesRelatedDetailsCited byChen J, Gu B, Wu G, Tu H, Si J, Xu Y and Andersson K (2018) The Effect of the 5-HT2A/2C Receptor Agonist DOI on Micturition in Rats with Chronic Spinal Cord InjuryJournal of Urology, VOL. 189, NO. 5, (1982-1988), Online publication date: 1-May-2013.Nakayama J, Takao T, Kiuchi H, Yamamoto K, Fukuhara S, Miyagawa Y, Aoki M, Iwatsuki K, Yoshimine T, Ueno M, Yamashita T, Nonomura N, Tsujimura A and Okuyama A (2018) Olfactory Mucosal Transplantation After Spinal Cord Injury Improves Voiding Efficiency by Suppressing Detrusor-Sphincter Dyssynergia in RatsJournal of Urology, VOL. 184, NO. 2, (775-782), Online publication date: 1-Aug-2010. Volume 171Issue 1January 2004Page: 472-477 Advertisement Copyright & Permissions© 2004 by American Urological Association, Inc.Keywordsbladderrats, Sprague-Dawleyurethraspinal cordreceptors, opioidMetrics Author Information BAOJUN GU More articles by this author MATTHEW O. FRASER Financial interest and/or other relationship with Dynogen Pharmaceuticals. More articles by this author KARL B. THOR More articles by this author PAUL C. DOLBER More articles by this author Expand All Advertisement PDF downloadLoading ...
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