Articles: neuralgia.
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There is some evidence implicating receptor for advanced glycation end products (RAGE) signaling in the pathogenesis of neuropathic pain (NP). The objective was to investigate whether RAGE signaling in the dorsal root ganglion (DRG) might contribute to NP following peripheral nerve injury. ⋯ RAGE signaling may contribute to the pain hypersensitivity observed in the rat SNL model of NP. Although the precise mechanism remains to be established, NF-κB, TNF-α, and IL-1β likely play a role, together with the activation of SGCs.
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Systemic administration of oxaliplatin has no effect on the tumors in the central nervous system (CNS) due to the limited concentration of oxaliplatin in the cerebrospinal fluid (CSF), while it was clinically reported that oxaliplatin can induce acute encephalopathy. Currently, the impairment of neuronal functions in the CNS after systemic administration of oxaliplatin remains uninvestigated. ⋯ The findings of this study suggested that oxaliplatin in CSF may directly impair the normal function of central neurons and contribute to the rapid development of CNS-related side effects during chemotherapy. This provides novel targets to prevent oxaliplatin-induced acute painful neuropathy and encephalopathy.
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Despite intense investigation, the mechanisms of the different forms of trigeminal neuropathic pain remain substantially unidentified. The transient receptor potential ankyrin 1 channel (encoded by TRPA1) has been reported to contribute to allodynia or hyperalgesia in some neuropathic pain models, including those produced by sciatic nerve constriction. However, the role of TRPA1 and the processes that cause trigeminal pain-like behaviours from nerve insult are poorly understood. ⋯ Nociception and hypersensitivity evoked by constriction of the infraorbital nerve was associated with intra- and perineural monocytic and macrophagic invasion and increased levels of oxidative stress by-products (hydrogen peroxide and 4-hydroxynonenal). Attenuation of monocyte/macrophage increase by systemic treatment with an antibody against the monocyte chemoattractant chemokine (C-C motif) ligand 2 (CCL2) or the macrophage-depleting agent, clodronate (both P < 0.05), was associated with reduced hydrogen peroxide and 4-hydroxynonenal perineural levels and pain-like behaviours (all P < 0.01), which were abated by perineural administration of HC-030031, α-lipoic acid or the anti-CCL2 antibody (all P < 0.001). The present findings propose that, in the constriction of the infraorbital nerve model of trigeminal neuropathic pain, pain-like behaviours are entirely mediated by the TRPA1 channel, targeted by increased oxidative stress by-products released from monocytes and macrophages clumping at the site of nerve injury.
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J Pharmacol Toxicol Methods · May 2016
Swing time ratio, a new parameter of gait disturbance, for the evaluation of the severity of neuropathic pain in a rat model of partial sciatic nerve ligation.
Dynamic weight bearing tests are used to evaluate the chronic pain severity in animal models of nociceptive pain (such as osteoarthritis); however, common tests frequently fail to collect the characteristics of neuropathic pain such as allodynia, because surgical intervention which is sometimes required to establish the models causes both nociceptive and neuropathic pain. ⋯ STR is sensitive to claudication of rats with PSL, providing a new scale to evaluate neuropathic pain in addition to conventional tests. Moreover, STR analysis enables us to evaluate walking function of animal models after neuropathic injury, which is quite important to judge the effectiveness of new treatments and analgesics.