Biphasic effects of intracerebroventricular interleukin-1 beta on mechanical nociception in the rat.
The effects of interleukin-1 beta on the mechanical nociceptive threshold in rat were examined using the paw-pressure test. An intracerebroventricular (i.c.v.) injection of interleukin-1 beta at doses of 10 and 100 pg/rat caused hyperalgesia to mechanical stimuli. Higher doses of interleukin-1 beta (1 and 10 ng/rat) induced an analgesic effect. The coadministration of the interleukin-1 receptor antagonist completely antagonized the hyperalgesic and analgesic effects of interleukin-1 beta. An i.c.v. injection of alpha-helical-corticotropin-releasing factor [9-41] 15 min prior to interleukin-1 beta administration completely blocked the hyperalgesic and analgesic effects of interleukin-1 beta. An i.c.v. injection of sodium salicylate 15 min prior to interleukin-1 beta administration inhibited the hyperalgesic effect of interleukin-1 beta, but not the analgesic effect. These results suggest that interleukin-1 beta produces biphasic effects on the mechanical nociceptive threshold through the interleukin-1 receptor in the brain and that a corticotropin-releasing factor-mediated pathway is involved. Furthermore, the hyperalgesic effect of interleukin-1 beta may be mediated by prostaglandins.
Yabuuchi
K
K
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kyoto University, Japan.
Nishiyori
A
A
Minami
M
M
Satoh
M
M
D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology; D006727:Hormone Antagonists / Q000494:pharmacology; D006930:Hyperalgesia / Q000209:etiology / Q000503:physiopathology*; D007276:Injections, Intraventricular; D007375:Interleukin-1 / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017472:Receptors, Interleukin-1 / Q000037:antagonists & inhibitors; D012980:Sodium Salicylate / Q000494:pharmacology
D006727:Hormone Antagonists; D007375:Interleukin-1; D010446:Peptide Fragments; D017472:Receptors, Interleukin-1; D003346:Corticotropin-Releasing Hormone; C045089:corticotropin releasing hormone (9-41); D012980:Sodium Salicylate