Repeated activation of delta opiod receptors counteracts nerve injury-induced TNF-α up-regulation in the sciatic nerve of rats with neuropathic pain: A possible correlation with delta opiod receptors-mediated antiallodinic effect.

Despite mu opioid receptor agonists are the cornerstones of moderate-to-severe acute pain treatment, their effectiveness in chronic pain conditions is controversial. In contrast to mu opioid receptor agonists, a number of studies have reported the effectiveness of delta opioid receptor agonists on neuropathic pain strengthening the idea that delta opioid receptors gain importance when chronic pain develops. Among other effects, it has been shown that delta opioid receptor activation in optic nerve astrocytes inhibits tumor necrosis factor-α-mediated inflammation in response to severe hypoxia.

The antagonistic effect of the sigma 1 receptor ligand (+)-MR200 on persistent pain induced by inflammation.

Objective And Design: The sigma 1 (σ1) receptor, which is widely distributed in the CNS in areas that are known to be important for pain control, may play a role in persistent pain characterized by the hypersensitivity of nociceptive transmission. Here, we investigated the effect of σ1 blockade in an inflammatory pain model.

Treatment And Methods: An intraplantar injection of carrageenan (2 %) was used to induce paw inflammation.

Effects of a selective sigma 1 antagonist compound on inflammatory pain.

The compound (−)-MRV3 [(−)-Methyl (1S,2R)-2-[(4-Hydroxy-4-phenylpiperidin-1-yl)-methyl]-1-phenylcyclopropanecarboxylate] has an assessed antagonistsigma 1 (σ1) profile and showed improved σ1/σ2 selectivity with respect to the parent compound(+)-MR200. The σ1 receptor is reported to play arole in both central sensitization and pain hypersensitivity,which suggests a potential use of σ1 antagonists forthe treatment of persistent pain conditions. The present study was performed to assess the effects of theselective σ1 antagonist (−)-MRV3, in carrageenan-inducedinflammatory hyperalgesia, allodynia and edema.

Trail interacts redundantly with nitric oxide in rat astrocytes: potential contribution to neurodegenerative processes.

The proapoptotic cytokine TRAIL has been shown to enhance amyloid-beta-dependent neurotoxicity. Here are reported interactions between TRAIL and nitric oxide (NO) in cultured rat astrocytes in vitro. Rat astrocytes expressed all TRAIL receptor mRNAs and proteins.

In vivo evaluation of (+)-MR200 as a new selective sigma ligand modulating MOP, DOP and KOP supraspinal analgesia.

The compound (+)-MR200 [(+)-methyl (1R,2S)-2-{[4-(4-chlorophenyl)-4-hydroxypiperidin-1-yl]methyl}-1-phenylcyclopropanecarboxylate] is a sigma ligand with increased affinity and selectivity compared to the structurally related ligand haloperidol. From the results of a previous study on the modulation of a systemically injected KOP opioid agonist analgesia by (+)-MR200, we analysed the influence of this sigma ligand on the antinociceptive effect of centrally injected MOP, DOP, and KOP selective agonists using the tail-flick test in rats. The results obtained confirmed that systemic administration of (+)-MR200 (1mg/Kg s.

Effect of supraspinal Nocistatin on Nociceptin/Orphanin FQ antagonism of selective opioid analgesia.

Nocistatin and Nociceptin/Orphanin FQ are two neuropeptides derived from the same precursor protein, pre-pro-Nociceptin. Nocistatin does not bind to Nociceptin/Orphanin FQ peptide (NOP) receptor but it antagonizes the allodynic and hyperalgesic effect of intrathecal (i.t.

Growth hormone protects human lymphocytes from irradiation-induced cell death.

1. Undesired effects of cancer radiotherapy mainly affect the hematopoietic system. Growth hormone (GH) participates in both hematopoiesis and modulation of the immune response.