Increase of nociceptive threshold induced by intrathecal injection of interleukin-1beta in normal and carrageenan inflammatory rat.
The present study was to investigate the effect of intrathecal (i.t.) injection of interleukin-1 beta (IL-1 beta) on nociception in normal and inflammatory rats. Peripheral inflammation was induced by intraplantar injection (i.pl.) of carrageenan into unilateral hind paw. The nociceptive threshold to noxious thermal stimulation was measured by the paw withdrawal latency (PWL). Intrathecal injection of IL-1 beta (10 ng, 100 ng) significantly increased PWL in normal rats, the peak occurred at 5 min and the effect lasted for 30 min. Similarly, IL-1 beta (10 ng, 100 ng, i.t.) significantly increased the PWL and lasted for more than 60 min in inflammatory rats. Both in normal and inflammatory rats, the IL-1 beta-induced antinociceptive effect was completely abolished by IL-1ra (50 ng, i.t.), and apparently attenuated by naloxone (10 microg, i.t.) or mianserin (20 microg, i.t.). These results suggest that IL-1 beta produces antinociceptive effect by binding IL-1 receptor at the spinal level, and is related to the activation of opioid and 5-HT systems.
Department of Neurobiology, State Key Laboratory of Medical Neurobiology, Medical Center of Fudan University, (The Former Shanghai Medical University), Shanghai, 200032, China.
Guang-Chen
GC
Ji
Yu-qui
YQ
Zhang
Fei
F
Ma
Gen-Cheng
GC
Wu
D000818:Animals; D002351:Carrageenan / Q000494:pharmacology*; D007249:Inflammation / Q000188:drug therapy; D007278:Injections, Spinal; D007375:Interleukin-1 / Q000008:administration & dosage* / Q000627:therapeutic use*; D008297:Male; D008803:Mianserin / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010146:Pain / Q000188:drug therapy*; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012702:Serotonin Antagonists / Q000494:pharmacology; D013997:Time Factors
D007375:Interleukin-1; D009292:Narcotic Antagonists; D012702:Serotonin Antagonists; D008803:Mianserin; D009270:Naloxone; D002351:Carrageenan