Acute anal stretch inhibits NMDA-dependent pelvic-urethra reflex potentiation via spinal GABAergic inhibition in anesthetized rats

Sung Lang Chen, Yu Hui Huang, Yu Lin Kao, Gin Den Chen, Chen Li Cheng, Hsien Yu Peng, Jiuan Miaw Liao, Pei Chen Huang, Shih Jei Tsai, Tzer Bin Lin

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The impact of acute anal stretch on the pelvic-urethra reflex potentiation was examined in urethane-anesthetized rats by recording the external urethra sphincter electromyogram activity evoked by the pelvic afferent stimulation. Test stimulation (1 stimulation/30 s) evoked a baseline reflex activity with a single action potential that was abolished by gallamine (5 mg/kg iv). On the other hand, the repetitive stimulation (1 stimulation/1 s) induced spinal reflex potentiation (SRP) that was attenuated by intrathecal 6-cyano-7- nitroquinoxaline-2,4-dione (a glutamatergic α-amino-3-hydroxy-5-methyl-4- isoxazoleproprionat receptor antagonist, 100 μM, 10 μl) and D-2-amino-5-phosphonovalerate [a glutamatergic N-methyl-D-aspartate (NMDA) antagonist, 100 μM, 10 μl]. Acute anal stretch using a mosquito clamp with a distance of 4 mm exhibited no effect, whereas distances of 8 mm attenuated and 12 mm abolished the repetitive stimulation-induced SRP. Intrathecal NMDA (100 μM, 10 μl) reversed the abolition on SRP caused by anal stretch. On the other hand, pretreated bicuculline [γ-aminobutyric acid (GABA) A receptor antagonist, 100 μM, 10 μl] but not hydroxysaclofen (GABAB receptor antagonist) counteracted the abolition on the repetitive stimulation-induced SRP caused by the anal stretch. All of the results suggested that anal stretch may be used as an adjunct to assist voiding dysfunction in patients with overactive urethra sphincter and that GABAergic neurotransmission is important in the neural mechanisms underlying external urethra sphincter activity inhibited by anal stretch.

Original languageEnglish
JournalAmerican Journal of Physiology - Renal Physiology
Volume295
Issue number4
DOIs
Publication statusPublished - Oct 2008
Externally publishedYes

Keywords

  • Bicuculline
  • Glutamate
  • Hydroxysaclofen
  • Spinal cord
  • Voiding dysfunction

ASJC Scopus subject areas

  • Physiology
  • Urology

Fingerprint Dive into the research topics of 'Acute anal stretch inhibits NMDA-dependent pelvic-urethra reflex potentiation via spinal GABAergic inhibition in anesthetized rats'. Together they form a unique fingerprint.

  • Cite this