Interleukin-1beta increases spinal cord wind-up activity in normal but not in monoarthritic rats.
Cytokines produced by spinal cord glia after peripheral inflammation, infection or trauma have a relevant role in the maintenance of pain states. The effect of intrathecally administered interleukin-1beta (IL-1beta) on spinal cord nociceptive transmission was studied in normal and monoarthritic rats by assessing wind-up activity in a C-fiber-mediated reflex paradigm evoked by repetitive (1 Hz) electric stimulation. Low i.t. doses of IL-1beta (0.03, 0.12, 0.5 and 2.0 ng) dose-dependently enhanced wind-up activity in normal rats, while higher doses (8.0 ng) only produced a marginal unsignificant effect. IL-1beta administration to monoarthritic rats did not significantly change wind-up scores at any dose. Adaptive changes developed in the spinal cord during chronic pain may underlie the ineffectiveness of exogenous IL-1beta to up-regulate nociceptive transmission.
Constandil
Luis
L
Laboratory of Neurobiology, Department of Biological Sciences, Faculty of Chemistry and Biology, University of Santiago of Chile, Casilla 40 Correo 33, Santiago, Chile.
Pelissier
Teresa
T
Soto-Moyano
Rubén
R
Mondaca
Mauricio
M
Sáez
Hernán
H
Laurido
Claudio
C
Muñoz
Carlos
C
López
Nandy
N
Hernández
Alejandro
A
D000818:Animals; D001169:Arthritis, Experimental / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D007278:Injections, Spinal / Q000379:methods; D007375:Interleukin-1 / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012018:Reflex / Q000187:drug effects*; D013116:Spinal Cord / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors
D007375:Interleukin-1