Expression of two cyclooxygenases in spinal cords of formalin rats
ZHANG Fei-yu
L(U) Ya-lin
DONG Jian
ZHANG Jie-fu
LI Yan
Abstract：Objective To compare the expression of two cyclooxygenase (COX) isoforms (COX-1 and COX-2) in the spinal cord of rats with inflammatory pain following peripheral formalin injection. Methods Experiments were performed on adult male Sprague-Dawley rats. 100μl of 5% formalin were injected subcutaneously into plantar hind paw of 30 rats to induce pain. The changes of COX-1 and COX-2 expression were evaluated by western blot in 30 rats, respectively at 2 hours, 6 hours, 1 day, 3 days, 7 days and 14 days after injection. The control group rats were injected with 100 μl of 0.9% saline instead of formalin in 20 rats. Results The expression of COX-1 significantly increased at 1day, 3 days, 7 days and 14 days, but the expression of COX-2 only transiently increased at 2 hours. Conclusions COX-1 and COX-2 are increasingly expressed in the spinal cord, furthermore,spinal COX-2 expression is induced early and transiently increased. COX-1 is up-regulated later and remains elevated for long time, which may explain the long-term hyperalgesia evoked by formalin injection.
Keywords：PainFormalinEpoxide hydrolasesWestern blot
Publication Date：2011-01-01
Online Publishing Date：2026-09-14(First online date of this platform, not the publication date of the document)