Cyclooxygenase-2 inhibitor SC-236 attenuates mechanical allodynia following nerve root injury in rats

• Published in: Journal of orthopaedic research Vol. 18; no. 6; p. 977
• Main Authors: Deleo, T A, Hashizume, H, Rutkowski, M D, Weinstein, T N
• Format: Journal Article
• Language: English
• Published: United States 01-11-2000
• Subjects: Animals; Cyclooxygenase Inhibitors - pharmacology; Denervation - adverse effects; Disease Models, Animal; Hyperalgesia - drug therapy; Hyperalgesia - etiology; Hyperalgesia - physiopathology; Low Back Pain - drug therapy; Low Back Pain - etiology; Low Back Pain - physiopathology; Male; Mechanoreceptors - drug effects; Mechanoreceptors - pathology; Mechanoreceptors - physiopathology; Pain Threshold - drug effects; Pain Threshold - physiology; Physical Stimulation - adverse effects; Pyrazoles - pharmacology; Radiculopathy - complications; Radiculopathy - drug therapy; Radiculopathy - physiopathology; Rats; Rats, Sprague-Dawley; Spinal Nerve Roots - drug effects; Spinal Nerve Roots - injuries; Spinal Nerve Roots - physiopathology; Sulfonamides - pharmacology
• ISSN: 0736-0266
• DOI: 10.1002/jor.1100180618

Low back pain is a common problem, affecting approximately two-thirds of the adult population. Of these individuals, a significant percentage will exhibit symptoms of radicular pain or sciatica. The purpose of this study was to determine the effect of one systemic (2 mg/kg) or intrathecal (0.2 mg/kg) dose of a selective cyclooxygenase-2 inhibitor (SC-236) in decreasing existing mechanical allodynia in a rat model of radiculopathy. Gait disturbance and mechanical allodynia (increased response to non-noxious von Frey monofilament stimuli) were assessed daily until the rats were killed 7 days after surgery. Robust mechanical allodynia developed in the rats in all groups except for those in the sham group by day 1 after surgery. Mechanical allodynia was significantly lower in the rats that received the systemic or the intrathecal dose of SC-236 than in those in the vehicle control group (analysis of variance followed by Bonferroni multiple comparison test, p = 0.002). The intrathecal drug route of administration produced greater attenuation in allodynia than the systemic dose, supporting a central mechanism of action of the cyclooxygenase-2 inhibitor (p = 0.002). The hypothesis that cyclooxygenase-2 is involved in spinal nociceptive processing after a nerve root injury was supported by this study. In addition, these data support continued basic science research to further elucidate central inflammatory processes that follow nerve root injury.