NEUROPEPTIDE FF IN THE RAT SPINAL-CORD DURING CARRAGEENAN INFLAMMATION

The role of neuropeptide FF (NPFF) in the modulation of spinal nocicep tion was studied in rats with carrageenan inflammation in the hind paw . Normally no NPFF-ir neuronal cell bodies are found in the spinal cor d. During inflammation NPFF-neurons were seen in an area receiving inn ervation from the inflamed hind limb, but in rats pretreated with morp hine no NPFF-ir neurons were found. NPFF or IgG from NPFF immunoserum administered intrathecally had no effect in thermal and mechanical noc iceptive tests. Morphine produced significant antinociception in both tests in the inflamed paw, but the effect was not modified by NPFF. Th ese findings differ from the effects of intrathecal administration of NPFF and opioids in acute thermal tests when no inflammation is presen t. The role of NPFF in the modulation of nociception in the spinal cor d may be markedly changed during acute inflammation. (C) 1997 Elsevier Science Inc.