Articles: hyperalgesia.
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A burn is a severe injury, and the resulting pain can be very significant. Currently, opioids are the primary method of pain management, but these drugs have side effects; thus, it is of prime focus to research the mechanisms of pain formation and analgesic drugs. ⋯ TMP alleviates nociceptive transmission of burn-injury pain mediated by the P2X3 receptor.
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Leconotide is an omega-conotoxin that blocks neuronal voltage sensitive calcium channels. This study compared the antihyperalgesic potencies of leconotide and ziconotide given intravenously alone and in combinations with a potassium channel modulator flupirtine, given intraperitoneally, in a rat model of diabetic neuropathic pain. ⋯ Leconotide could have wider clinical applications than ziconotide. Unlike ziconotide, powerful antihyperalgesia without side effects can be achieved by intravenous administration of leconotide thus avoiding the need for an intrathecal injection.
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Curcumin has diverse therapeutic effects, such as anti-inflammatory, anti-oxidant, anti-cancer, and antimicrobial activities. The vanilloid moiety of curcumin is considered important for activation of the transient receptor potential vanilloid 1 (TRPV1), which plays an important role in nociception. However, very little is known about the effects of curcumin on nociception. ⋯ Intraperitoneally administered curcumin blocked capsaicin-induced thermal hyperalgesia in a dose-dependent manner. Whereas curcumin reduced capsaicin-induced currents in a dose-dependent manner in both trigeminal ganglion neurons and TRPV1-expressing HEK 293 cells, curcumin did not affect heat-induced TRPV1 currents. Taken together, our results indicate that curcumin blocks capsaicin-induced TRPV1 activation and thereby inhibits TRPV1-mediated pain hypersensitivity.
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The aim of this study was to assess the preventative effect of ketamine on the exaggerated postoperative pain observed in sufentanil-treated mice and its ability to improve the analgesic effectiveness of morphine during the postoperative period in an orthopaedic model of pain. ⋯ Our results suggest that pre-emptive use of ketamine is useful in orthopaedic surgery in this mice model to diminish short- and long-term hyperalgesia, but also to improve morphine effectiveness leading to a better mobilization and more rapid rehabilitation.
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Animal models for mechanical pressure or heat nociception usually only measure the threshold response latency. In this study, the effect of typical sensitising treatments on the lasting nocifensive behaviour elicited after a supra-threshold heating stimulus - the hyperpathic component of hypernociception - was assessed. Male Wistar rats received either intra-plantar (i.pl.) injection of 350ng PGE(2) (50microL) or topical application (t.a.) of 100% dimethylsulfoxide (DMSO), and 10mM capsaicin. ⋯ Capsaicin neonatal treatment (CNT) (50mg/kg) reduced the sensitisation induced by DMSO and capsaicin (P<0.01), but not that induced by PGE(2). These data suggest that the heat-induced lasting nociception is probably conveyed by Aeth nociceptors, and PGE(2) seems to be more selective to induce this phenomenon than the thermal threshold lowering. In addition, this hyperpathic effect induced by DMSO and capsaicin seems to be indirectly mediated by PGE(2) and C-fibres.