Involvement of nitric oxide in the nociception of kyotorphin, TYR-CAV and MIF-s analogues in the rat spinal cord.

Abstract

The spinal analgesic effects of Kyotorphin (Kyo) and Melanocyte-inhibiting factor (MIF-l) were studied during acute pain in rats chronically implanted with intrathecal (i.t.) cannulas. Kyo (5 micrograms), t-Cav (5 micrograms), Tyr-Cav (5 micrograms), L-NAME (1500 micrograms), MIF-Cav (200-400 micrograms) and MIF-sLeu (200 micrograms) exerted antinociceptive effects in both tests. The coadministration of Kyo + L-NAME enhanced the nociceptive effect compared with L-NAME (PP) or Kyo alone (PP, TF). The combination of Tyr-Cav + L-NAME enhanced the antinociceptive effect compared with L-NAME (PP) or Tyr-Cav alone (TF, PP). MIF-l (200 micrograms) had a weak antinociceptive effect in both tests. The coadministration of MIF-Cav + L-NAME enhanced the nociceptive effect compared with L-NAME (TF) or MIF-Cav alone (TF). The combination of MIF-sLeu + L-NAME enhanced the antinociceptive effect compared with L-NAME (TF) or MIF-sLeu alone (TF, PP). The results suggest that nitric oxide (NO) is involved in the antinociceptive effects of neuropeptides in the rat spinal cord.

• Authors: A Bocheva, M Lazarova
• Journal: Methods and findings in experimental and clinical pharmacology (Methods Find Exp Clin Pharmacol) Vol. 25 Issue 2 Pg. 91-5 (Mar 2003) ISSN: 0379-0355 [Print] Spain
• PMID: 12731454 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Analgesics
• Endorphins
• kyotorphin
• Nitric Oxide
• MSH Release-Inhibiting Hormone
• Nitric Oxide Synthase
• NG-Nitroarginine Methyl Ester

Topics

• Acute Disease
• Analgesics (pharmacology)
• Animals
• Drug Interactions
• Drug Synergism
• Endorphins (metabolism, pharmacology)
• Injections, Spinal
• MSH Release-Inhibiting Hormone (analogs & derivatives, metabolism, pharmacology)
• Male
• NG-Nitroarginine Methyl Ester (pharmacology)
• Nitric Oxide (metabolism)
• Nitric Oxide Synthase (antagonists & inhibitors)
• Pain (drug therapy, metabolism, physiopathology)
• Pain Threshold (drug effects)
• Rats
• Rats, Wistar
• Spinal Cord (drug effects, metabolism)
• Time Factors