Functional and fine structural characteristics of the sensory neuron blocking effect of capsaicin

  • J. Szolcsányi
  • Aurelia Jancsó-Gábor
  • F. Joó


In the eye of rats the long-lasting specific desensitization induced by local or systemic capsaicin treatment is characterized by three phases: 1. complete insensitivity, 2. decreased sensitivity and a tendency to rapid adaptation, 3. normal initial sensitivity with a tendency to rapid adaptation to chemical pain stimuli. A low density of microvesicles and swollen mitochondria were found after local capsaicin treatment in certain nerve endings of the cornea of rats, but no signs of axonal degeneration or alteration in fine structure of non-neural elements were seen. Systemic capsaicin desensitization induced selective mitochondrial swelling in B type of neurons of the trigeminal ganglion which was demonstrable even 60 days after the pretreatment. Actinomycin-D, 8-azaguanine, 6-azauracil, aminopterin, mannomustin or cycloheximide in high doses did not alter the desensitizing effect of systemic capsaicin treatment. However, pretreatment of rats with colchicine or vinblastine prolonged the desensitizing effect of local capsaicin application, probably by inhibiting the axonal flow. It is concluded that capsaicin is a specific sensory neuron blocking agent having a practically irreversible effect in rats and guineapigs.

Key words

Sensory Neuron Blockage Pain Capsaicin Cornea Ultrastructure 


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Copyright information

© Springer-Verlag 1975

Authors and Affiliations

  • J. Szolcsányi
    • 1
    • 2
  • Aurelia Jancsó-Gábor
    • 1
    • 2
  • F. Joó
    • 1
    • 2
  1. 1.Department of PharmacologyUniversity Medical SchoolPécsHungary
  2. 2.Electron Microscope LaboratoryBiological Research Center of Hungarian Academy of SciencesSzeged

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