Protective action of ruthenium red toward capsaicin desensitization of sensory fibers

Neurosci Lett. 1988 May 26;88(2):201-5. doi: 10.1016/0304-3940(88)90126-7.


In the rat isolated urinary bladder, exposure to capsaicin (1 microM) produced a contraction thought to involve neuropeptide(s) release from sensory nerves. A second application of the drug had no motor effect indicating desensitization. The establishment of the desensitized state requires the presence of extracellular calcium. In the presence of Ruthenium red 9RR, 30 nM-10 microM) the first response to capsaicin was reduced and a concentration-dependent protection from capsaicin desensitization was observed. RR up to 10 microM had no inhibitory effect toward contractions produced by exogenous substance P nor by electrical stimulation of efferent nerves.

MeSH terms

  • Animals
  • Capsaicin / pharmacology*
  • Electric Stimulation
  • In Vitro Techniques
  • Male
  • Muscle Contraction / drug effects*
  • Muscles / drug effects
  • Muscles / innervation*
  • Muscles / physiology
  • Neurons, Afferent / drug effects
  • Neurons, Afferent / physiology*
  • Rats
  • Rats, Inbred Strains
  • Ruthenium / pharmacology*
  • Ruthenium Red / pharmacology*
  • Urinary Bladder / drug effects
  • Urinary Bladder / innervation
  • Urinary Bladder / physiology


  • Ruthenium Red
  • Ruthenium
  • Capsaicin