Articles: hyperalgesia.
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Spinal toll like receptor 3 is involved in chronic pancreatitis-induced mechanical allodynia of rat.
Mechanisms underlying pain in chronic pancreatitis (CP) are incompletely understood. Our previous data showed that astrocytes were actively involved. However, it was unclear how astrocytic activation was induced in CP conditions. In the present study, we hypothesized that toll-like receptors (TLRs) were involved in astrocytic activation and pain behavior in CP-induced pain. ⋯ These results suggest a probable "TLR3-astrocytes-IL-1β/MCP-1" pathway as a positive feedback loop in the spinal dorsal horn in CP conditions. TLR3-mediated neuroimmune interactions could be new targets for treating persistent pain in CP patients.
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A preconditioning stimulus can trigger a neuroprotective phenotype in the nervous system - a preconditioning nerve lesion causes a significant increase in axonal regeneration, and cerebral preconditioning protects against subsequent ischemia. We hypothesized that a preconditioning nerve lesion induces gene/protein modifications, neuronal changes, and immune activation that may affect pain sensation following subsequent nerve injury. We examined whether a preconditioning lesion affects neuropathic pain and neuroinflammation after peripheral nerve injury. ⋯ These results suggest that prior exposure to a mild nerve lesion protects against adverse effects of subsequent neuropathic injury, and that this conditioning-induced inhibition of pain hypersensitivity is not dependent on neuroinflammation in DRGs and spinal cord. Identifying the underlying mechanisms may have important implications for the understanding of neuropathic pain due to nerve injury.
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Transient receptor potential vanilloid 1 (TRPV1) is primarily expressed in central and peripheral terminals of non-myelinated primary afferent neurons. We previously showed that AS1928370, a novel TRPV1 antagonist that can prevent ligand-induced activation but not proton-induced activation, ameliorates neuropathic pain in rats without hyperthermic effect. In this study, we investigated its analgesic profile in mice. ⋯ Intrathecal administration of AS1928370 (30 µg/body) also significantly suppressed mechanical allodynia. In addition, AS1928370 showed no effect on locomotor activity up to 30 mg/kg p.o. These results suggest that spinal TRPV1 has an important role in the transmission of neuropathic pain and that the central nervous system (CNS) penetrant TRPV1 receptor antagonist AS1928370 is a promising candidate for treating neuropathic pain.
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Randomized Controlled Trial
Effect of a single dose of pregabalin on herpes zoster pain.
The effect of pregabalin on acute herpes zoster pain has not been previously evaluated. ⋯ Compared to an earlier study of gabapentin 900 mg for acute zoster pain and allodynia that followed a nearly identical protocol, pregabalin had a similar effect on pain and was well tolerated, with no difference from placebo on sleepiness. Common side effects of light-headedness, unsteady gait, and slowed thinking were almost identical to that observed in the earlier study of gabapentin. Subject recruitment proved difficult in part due to the widespread off-label use of gabapentin and pregabalin for acute zoster pain in our region of the USA.
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Swiss medical weekly · Jan 2011
Randomized Controlled TrialThe ED50 and ED95 of ketamine for prevention of postoperative hyperalgesia after remifentanil-based anaesthesia in patients undergoing laparoscopic cholecystectomy.
Various research programmes have shown that intraoperative infusion of remifentanil has been associated with postoperative hyperalgesia. Previous studies have demonstrated that low-dose ketamine can inhibit central sensitisation and prevent opioid-induced hyperalgesia (OIH). However, the optimal ketamine dose to prevent OIH has not been determined. In the present study we aimed to determine the ED50 and ED95 of ketamine for prevention of postoperative hyperalgesia after remifentanil-based anaesthesia in patients undergoing laparoscopic cholecystectomy. ⋯ The ED50 and ED95 of ketamine for prevention of postoperative hyperalgesia after remifentanil-based anaesthesia in patients undergoing laparoscopic cholecystectomy were 0.24 mg/kg and 0.33 mg/kg respectively.