TRPV1 mediates the uterine capsaicin-induced NMDA NR2B-dependent cross-organ reflex sensitization in anesthetized rats

Hsien Yu Peng, Hung Ming Chang, Shin Da Lee, Pei Chen Huang, Gin Den Chen, Cheng Hung Lai, Cheng Yuan Lai, Chun Hsien Chiu, Kwong Chung Tung, Tzer Bin Lin

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25 Citations (Scopus)

Abstract

Spinal cord-mediated cross-organ sensitization between the uterus and the lower urinary tract may underlie the high concurrence of obstetrical/ gynecological inflammation and chronic pelvic pain syndrome characterized by urogenital pain. However, the neural pathway and the neurotransmitters involved are still unknown. We tested the hypothesis that the excitation of capsaicin-sensitive primary afferent fibers arising from the uterus through the stimulation of transient receptor potential vanilloid 1 (TRPV1) induces cross-organ sensitization on the pelvic-urethra reflex activity. Capsaicin (1-1,000 μM, 0.05 ml) was instilled into the uterus to induce cross-organ reflex sensitization. Activation of capsaicin-sensitive primary afferent fibers by capsaicin instillation into the uterine horn sensitized the pelvic-urethra reflex activity that was reversed by an intrauterine pretreatment with capsaizepine, a TRPV1-selective antagonist. Intrathecal injection of AP5, a glutamatergic N-methyl-D-aspartate (NMDA) antagonist, and Co-101244, an NMDA NR2B-selective antagonist, both abolished the cross-organ reflex sensitization caused by capsaicin instillation. These results demonstrated that TRPV1 plays a crucial role in contributing to the capsaicin-sensitive primary afferent fibers mediating the glutamatergic NMDA-dependent cross-organ sensitization between the uterus and the lower urinary tract when there is a tissue injury.

Original languageEnglish
JournalAmerican Journal of Physiology - Renal Physiology
Volume295
Issue number5
DOIs
Publication statusPublished - Nov 2008
Externally publishedYes

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Keywords

  • C-fiber
  • Desensitization
  • Pain
  • Spinal cord

ASJC Scopus subject areas

  • Physiology
  • Urology

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