Lidocaine prevents noxious excitation of bladder afferents induced by intravesical capsaicin without interfering with the ensuing sensory desensitization: an experimental study in the rat

J Urol. 1998 Feb;159(2):567-70. doi: 10.1016/s0022-5347(01)63985-5.


Purpose: The effects of the local anesthetic lidocaine on the noxious excitation and subsequent desensitization of bladder sensory fibers, produced by intravesical capsaicin, were evaluated through c-fos activation in the spinal cord.

Materials and methods: Noxious excitation was demonstrated by counting Fos-immunoreactive (IR) cells occurring in the rat spinal cord 2 hours after intravesical administration of 1 mM. capsaicin, preceded or not by 2% lidocaine. Desensitization was studied by comparing the number of Fos-IR cells induced by 1% acetic acid in rats treated 24 hours before with 1 mM. intravesical capsaicin preceded or not by 2% lidocaine.

Results: Lidocaine instilled previously markedly reduced the number of Fos-IR spinal cells responding to capsaicin-induced bladder afferent excitation. Numbers of Fos-IR cells induced by acetic acid instillation in bladders desensitized by capsaicin administrated 24 hours before were not changed by lidocaine application prior to capsaicin.

Conclusions: These findings suggest that local anesthetic pretreatment of the bladder with lidocaine reduces the capsaicin-induced noxious excitation of the sensory fibers without decreasing their subsequent desensitization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Intravesical
  • Anesthetics, Local / pharmacology*
  • Animals
  • Capsaicin / pharmacology*
  • Female
  • Lidocaine / pharmacology*
  • Rats
  • Rats, Wistar
  • Urinary Bladder / drug effects*
  • Urinary Bladder / innervation*


  • Anesthetics, Local
  • Lidocaine
  • Capsaicin