Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0162473 (Frey)
 2,599 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have recently reported that injury to a lumbar root in a rat model of radiculopathy produces spinal glial activation associated with elevated proinflammatory cytokines. Based on our hypothesis that central neuroinflammatory processes may manifest clinically as radicular pain, we undertook pharmacological intervention using the immunosuppressive agent methotrexate (MTX). The L5 lumbar spinal root (central to the dorsal root ganglia) was exposed unilaterally and loosely constricted with chromic gut. In the prevention (phase I) study, MTX was administered intrathecally (1 mg/kg) and around the spinal root (1 mg/kg) at surgery and at days 2 and 4 postsurgery (group A). Saline injection was employed for the control group (group B). Sham operated animals were administered MTX to determine the potential for behavioral/neural side effects (group C). In the existing pain paradigm (phase II) study, the experiment was extended to day 14 with three additional groups. The same dose and method of delivery of MTX or saline was administered as in phase I in the first week on days 0, 2, and 4 and in the second week on days 7, 9, and 11 postsurgery. To measure the effects of MTX on existing behaviors saline was administered in the first week and MTX during the second (group D; Saline:MTX). The control group received saline during both weeks (group E; Saline:Saline). To examine the possible recurrence of radicular pain after MTX termination, MTX was given in the first week and saline in the second (group F; MTX:Saline). Gait disturbance and mechanical allodynia (using von Frey filaments) were assessed up to day 7 in the prevention study (Phase I) and day 14 in the existing pain paradigm (Phase II). The L5 spinal cord segments were harvested for assessment of immunohistochemical glial activation using the antibodies OX-42 (microglial marker) and glial fibrillary acidic protein (GFAP: astrocytic marker) and for the presence of Major Histocompatibility Complex (MHC) Class II expression. Group C (Sham+MTX) did not demonstrate any evidence of gait disturbance or mechanical allodynia after MTX administration. The rats in group B (Surgery+Saline) demonstrated mechanical allodynia from one day postsurgery to the time of euthanization. When allodynia was assessed using the 12 g von Frey filament, the MTX treated rats in group A showed significantly decreased mechanical allodynia as compared to the saline treated rats (group B) (repeated measured ANOVA, P<0.0001). In the phase II study, the rats in group D (Saline:MTX) and E (Saline:Saline) showed robust allodynia in the first week after the surgery. In the second week, mechanical allodynia significantly decreased in group D, while mechanical allodynia continued in the saline treated group (repeated measured ANOVA, P=0.0121). Allodynia was significantly attenuated in group F (MTX: Saline) as compared to the response in groups D and E at day 7 (one-way ANOVA, P<0.0001) and remained significantly lower as compared to group E up to day 11 postsurgery (one-way ANOVA, P9=0. 0013: P11=0.0048). OX-42 and GFAP expression were elevated in the gray matter of the L5 spinal section in all groups that underwent the root ligature with chromic gut (Groups A, B, D-F). There were no significant differences in glial activation between the groups. However, spinal expression of MHC II was markedly reduced in the MTX treated group as compared with the saline treated group. The exact mechanism of action of MTX in attenuating mechanical allodynia has not yet been elucidated. The present results indicate that MTX administration may offer a new treatment modality for radicular pain with or without disc herniation as well as directing new research into the development of novel immunomodulators for the treatment of chronic neuropathic and radicular pain.
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PMID:Central administration of methotrexate reduces mechanical allodynia in an animal model of radiculopathy/sciatica. 1092 9

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.
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PMID:Cyclooxygenase-2 inhibitor SC-236 attenuates mechanical allodynia following nerve root injury in rats. 1119 59