title: Effect of a 5-HT1A receptor agonist (8-OH-DPAT) on external urethral sphincter activity in a rat model of pudendal nerve injury.
abstract: Although serotonergic agents have been used to treat patients with stress urinary incontinence, the characteristics of the external urethral sphincter (EUS) activity activated by 5-HT receptors have not been extensively studied. This study examined the effects of the 5-HT(1A) receptor agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), on the EUS-electromyography and resistance of the urethra in a rat model with bilateral pudendal nerve injury (BPNI). Two measurements were utilized to assess the effects of the drug on bladder and urethral functions: the simultaneous recordings of transvesical pressure under isovolumetric conditions [isovolumetric intravesical pressure (IVP)] and urethral perfusion pressure, and the simultaneous recordings of IVP during continuously isotonic transvesical infusion with an open urethra (isotonic IVP) and EUS-electromyography. This study also evaluated the urethral continence using leak point pressure testing. The urethral perfusion pressure and leak point pressure measurements of BPNI rats reveal that 8-OH-DPAT significantly increased urethral resistance during the bladder storage phase, yet decreased resistance during the voiding phase. The entire EUS burst period was significantly prolonged, within which the average silent period increased and the frequency of burst discharges decreased. 8-OH-DPAT also improved the voiding efficiency, as evidenced by the detection of decreases in the contraction amplitude and residual volume, with increases in contraction duration and voided volume. These findings suggest that 8-OH-DPAT not only improved continence function, but also elevated the voiding function in a BPNI rat model.
authors.affiliation: Dept. of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, No. 250, Wuxing St., Taipei 11031, Taiwan.
authors.forename: Shih-Ching
authors.initials: SC
authors.lastname: Chen
authors.forename: Chen-Li
authors.initials: CL
authors.lastname: Cheng
authors.forename: Wen-Jia
authors.initials: WJ
authors.lastname: Fan
authors.forename: Jia-Jin Jason
authors.initials: JJ
authors.lastname: Chen
authors.forename: Chien-Hung
authors.initials: CH
authors.lastname: Lai
authors.forename: Chih-Wei
authors.initials: CW
authors.lastname: Peng
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D004576:Electromyography; D005260:Female; D008160:Lumbosacral Plexus / Q000293:injuries*; D023421:Models, Animal; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D010879:Piperazines / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044282:Receptor, Serotonin, 5-HT1A / Q000187:drug effects / Q000502:physiology; D058825:Serotonin 5-HT1 Receptor Agonists / Q000494:pharmacology* / Q000627:therapeutic use; D012702:Serotonin Antagonists / Q000494:pharmacology; D014521:Urethra / Q000187:drug effects* / Q000503:physiopathology*; D001743:Urinary Bladder / Q000294:innervation*; D014550:Urinary Incontinence, Stress / Q000503:physiopathology / Q000628:therapy
chemical_list: D010879:Piperazines; D011725:Pyridines; D058825:Serotonin 5-HT1 Receptor Agonists; D012702:Serotonin Antagonists; D044282:Receptor, Serotonin, 5-HT1A; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin