A new nitric oxide donor, NOC-18, exhibits a nociceptive effect in the rat formalin model

J Neurol Sci. 1996 Sep 15;141(1-2):1-5. doi: 10.1016/0022-510x(96)00102-5.


The utility of a new nitric oxide (NO) donor, NOC-18, and the contribution of the neurotransmitter NO to nociception in response to tissue injury in rats, were examined following the subcutaneous injection of formalin into the hindpaw. This model induces biphasic responses in pain-related behavior, such that C-fiber activation during the first phase triggers a state of central sensitization characterized by the second phase. Formalin-induced nociceptive behavior was facilitated by intracerebroventricular administration of NOC-18 in the second phase, but not the first phase. This enhancement was completely abolished by the soluble guanylate cyclase inhibitor, methylene blue. These findings indicate that NO causes nociception via the NO-cGMP pathway in the central nervous system and NOC-18 proved to be a convenient and useful tool for the investigation of nociception-related NO.

MeSH terms

  • Animals
  • Antidotes / pharmacology
  • Behavior, Animal / drug effects
  • Formaldehyde
  • Injections, Intraventricular
  • Injections, Subcutaneous
  • Male
  • Methylene Blue / pharmacology
  • Motor Activity / drug effects
  • Nitric Oxide / metabolism*
  • Nitric Oxide / pharmacology
  • Nitroso Compounds / metabolism
  • Nitroso Compounds / pharmacology*
  • Nociceptors / drug effects*
  • Pain / chemically induced
  • Pain / metabolism*
  • Rats
  • Rats, Sprague-Dawley


  • Antidotes
  • NOC 18
  • Nitroso Compounds
  • Formaldehyde
  • Nitric Oxide
  • Methylene Blue