Skip to main content
Log in

Nociceptin protects capsaicin-sensitive afferent fibers in the rat urinary bladder from desensitization

  • Original Article
  • Published:
Naunyn-Schmiedeberg's Archives of Pharmacology Aims and scope Submit manuscript

Abstract.

Chemical stimulation of primary afferent nerves in the rat urinary bladder in vivo with topical capsaicin (1 µg in 50 µl saline) determines a dual motor response, consisting of a contractile effect mediated by tachykinins released from sensory nerves in the bladder wall and a transient activation of a bladder-to-bladder micturition reflex organized at the supraspinal level (chemoceptive micturition reflex). Both responses undergo complete desensitization upon repeated applications of capsaicin. The i.v. administration of the novel neuropeptide nociceptin (100 nmol/kg) produced a long-lasting protection from capsaicin desensitization of afferent nerves which mediate the chemoceptive micturition reflex. In fact a chemoceptive micturition reflex could be repeatedly evoked by topical capsaicin in nociceptin-pretreated rats. In sharp contrast, nociceptin did not influence the development of desensitization of the local response to capsaicin, corresponding to the 'efferent' function of capsaicin-sensitive afferent neurons. These results suggest that the afferent and 'efferent' function of capsaicin-sensitive primary afferent neurons (CSPANs) in the rat bladder are differentiated by nociceptin. Alternative mechanisms underlying this phenomenon are discussed.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Author information

Authors and Affiliations

Authors

Additional information

Electronic Publication

Rights and permissions

Reprints and permissions

About this article

Cite this article

Giuliani, S., Lecci, A., Tramontana, M. et al. Nociceptin protects capsaicin-sensitive afferent fibers in the rat urinary bladder from desensitization. Naunyn-Schmiedeberg's Arch Pharmacol 360, 202–208 (1999). https://doi.org/10.1007/s002109900047

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s002109900047

Navigation