Naunyn-Schmiedeberg's archives of pharmacology
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Naunyn Schmiedebergs Arch. Pharmacol. · May 2013
Cannabinoid-mediated diversity of antinociceptive efficacy of parecoxib in Wistar and Sprague Dawley rats in the chronic constriction injury model of neuropathic pain.
We studied nociceptive behavior and the effects of analgesics in Wistar (Wist) and Sprague Dawley (SPD) rats and in CB1 receptor-deficient mice with neuropathic pain experimentally. Neuropathic pain was induced by loose ligation of the sciatic nerve (chronic constriction injury, CCI). In CCI rats from both strains, cold allodynia and a reduced thermal pain threshold were detected, whereas no effect was found in the hot plate test. ⋯ Receptor binding experiments showed increased CB1 binding in parecoxib-treated CCI Wist rats. Levels of the CB1 receptor mRNA remained constant in both strains of rats 5 days after surgery. Differences in antinociceptive activity might be due to modification of the cannabinoid system.
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Naunyn Schmiedebergs Arch. Pharmacol. · Jan 2013
Comparative StudyPharmacological activation of heme oxygenase (HO)-1/carbon monoxide pathway prevents the development of peripheral neuropathic pain in Wistar rats.
Recent studies have emphasized the contribution of neuroinflammation and oxido-nitrosative stress to neuropathic pain. Both, heme oxygenase (HO)-1 and carbon monoxide (CO) play an important role in regulating free radical generation and inflammation. Herein, we investigated the role of HO-1/CO pathway, by using hemin, a selective HO activator, and CO-releasing molecule (CORM)-2, a CO-releasing agent, in rat sciatic nerve chronic constriction injury (CCI)-induced neuropathic pain. ⋯ Both hemin and CORM-2 produced ameliorative beneficial effects that paralleled with the extent of reduction of oxido-nitrosative stress and pro-inflammatory cytokines. Also, hemin and CORM-2 significantly improved the levels of HO-1 and activity of anti-oxidant enzymes such as superoxide dismutase and catalase. Thus, it may be concluded that chronic pharmacological activation of HO-1/CO pathway may prevent the development of behavioral symptoms of neuropathic pain, through an activation of anti-inflammatory and anti-oxidant mechanisms.
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Naunyn Schmiedebergs Arch. Pharmacol. · Jan 2013
Modulation by the noble gas argon of the catalytic and thrombolytic efficiency of tissue plasminogen activator.
Argon has been shown to provide cortical as well as, under certain conditions, subcortical neuroprotection in all models so far (middle cerebral artery occlusion, trauma, neonatal asphyxia, etc.). This has led to the suggestion that argon could be a cost-efficient alternative to xenon, a metabolically inert gas thought to be gold standard in gas pharmacology but whose clinical development suffers its little availability and excessive cost of production. However, whether argon interacts with the thrombolytic agent tissue plasminogen activator, which is the only approved therapy of acute ischemic stroke to date, still remains unknown. ⋯ Low and high concentrations of argon of 25 and 75 vol% respectively block and increase tPA enzymatic and thrombolytic efficiency. The possible use of argon at low and high concentrations in the treatment of acute ischemic stroke if given during ischemia or after tPA-induced reperfusion is discussed as regards to its neuroprotectant action and its inhibiting and facilitating effects on tPA-induced thrombolysis. The mechanisms of argon-tPA interactions are also discussed.
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Naunyn Schmiedebergs Arch. Pharmacol. · Nov 2012
CCL2 released at tumoral level contributes to the hyperalgesia evoked by intratibial inoculation of NCTC 2472 but not B16-F10 cells in mice.
The participation of the chemokine CCL2 (monocyte chemoattractant protein-1) in inflammatory and neuropathic pain is well established. Furthermore, the release of CCL2 from a NCTC 2472 cells-evoked tumor and its involvement in the upregulation of calcium channel α2δ1 subunit of nociceptors was demonstrated. In the present experiments, we have tried to determine whether the increase in CCL2 levels is a common property of painful tumors and, in consequence, the administration of a chemokine receptor type 2 (CCR2) antagonist can inhibit tumoral hypernociception. ⋯ Thermal hyperalgesia was also inhibited by the peritumoral administration of a neutralizing CCL2 antibody. In contrast, no change in CCL2 levels was observed in mice inoculated with B16-F10 cells, and RS 504393 did not inhibit the hypernociceptive reactions evoked by their intratibial inoculation. The peripheral release of CCL2 is involved in the development of thermal and mechanical hyperalgesia, but not mechanical allodynia evoked by the inoculation of NCTC 2472 cells, whereas this chemokine seems unrelated to the hypernociception induced by B16-F10 cells.
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Naunyn Schmiedebergs Arch. Pharmacol. · Aug 2012
(-)-Epigallocatechin-3-gallate (EGCG) attenuates functional deficits and morphological alterations by diminishing apoptotic gene overexpression in skeletal muscles after sciatic nerve crush injury.
Muscle degeneration and impairment following nerve injury could lead to apoptosis as a result of increased levels of reactive oxygen species. This activates the apoptotic cascade through mitochondrial dysfunction and damage to lipids, proteins, and DNA. In considering of the multifactorial protective properties of green tea polyphenols (-)-epigallocatechin-3-gallate (EGCG), this study investigates whether EGCG treatment does improve skeletal muscle function impairments, induced by crushing of the sciatic nerve. ⋯ Semi-quantitative desmin immunohistochemistry revealed intense staining in the saline-treated injured animals, whereas EGCG treatment decreased the desmin immunoreactivity back to sham control levels. Using RT-PCR, EGCG treatment induced a significant anti-apoptotic effect in injured muscle tissues by normalizing the Bax/Bcl-2 ratio back to baseline levels and inhibiting overexpression of the p53 apoptotic gene at days 3 and 7 post-surgery. In conclusion, our results demonstrate that EGCG enhances functional recovery, protects muscle fibers from cellular death by activating anti-apoptotic signaling pathway, and improves morphological recovery in skeletal muscle after nerve injuries.