Articles: hyperalgesia.
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Journal of anesthesia · Dec 2018
Randomized Controlled TrialHigh-dose intraoperative remifentanil infusion increases early postoperative analgesic consumption: a prospective, randomized, double-blind controlled study.
The purpose of this study was to determine whether intraoperative infusion of remifentanil induces acute tolerance to opioids, and compare the postoperative pain and opioid consumption by the effect site concentrations of remifentanil. ⋯ Intraoperative infusion of remifentanil with 12 ng/ml of effect site concentration in patients undergoing gastrectomy increases early postoperative fentanyl requirement. Acute opioid tolerance would be developed by higher concentration of remifentanil than dosage of common anesthetic practice.
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Little is known about the functional relationship between endoplasmic reticulum (ER) stress and development of pain hypersensitivity after nerve injury. The aim of this study was to investigate the role of ER stress in the development of pain hypersensitivity in the dorsal root ganglion (DRG) after spinal nerve ligation (SNL). SNL was performed in male Sprague-Dawley rats. ⋯ Treatment with salubrinal inhibited CHOP expression in L5 DRG and alleviated pain hypersensitivity for 5 days after SNL. Tunicamycin induced ER stress in the DRG and pain hypersensitivity 2 h after treatment. These results demonstrated that ER stress is induced in the injured DRG and contributes to the development of pain hypersensitivity after nerve injury.
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Complex regional pain syndrome (CRPS) is a disorder that involves abnormal inflammation and nerve dysfunction frequently resistant to a broad range of treatments. Peripheral nerve stimulation with electroacupuncture (EA) has been widely used in different clinical conditions to control pain and inflammation; however, the use of EA in the treatment of CRPS is under investigation. In this study, we explore the effects of EA on hyperalgesia and edema induced in an animal model of chronic post-ischemia pain (CPIP model) and the possible involvement of endothelin receptor type B (ETB) in this effect. ⋯ Furthermore, the expression of peripheral ETB receptors was increased after EA treatments, as measured by western blot. These results may suggest that EA's analgesic effect is synergic with ETB receptor activation in the periphery, as well as central (spinal cord) ETB receptor blockade. These data support the use of EA as a nonpharmacological approach for the management of CRPS-I, in an adjuvant manner to ETB receptor targeting drugs.
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Neuroscience letters · Nov 2018
A new central post-stroke pain rat model: autologous blood injected thalamic hemorrhage involved increased expression of P2X4 receptor.
Stroke is the leading cause of disability and death in the world. Central post-stroke pain (CPSP), a central neuropathic pain syndrome occurring after cerebral stroke, is a serious problem. But on account of the lack of reliable animal models, the mechanisms underlying CPSP remains poorly understood. ⋯ A significant alleviation of mechanical allodynia was achieved following the administration of adrenergic antidepressants and antiepileptics. Meanwhile, we found a significant decrease in P2 × 4 receptor expression after treatment with these drugs. Taken together, our results suggest that targeting P2 × 4 receptor may be effective in the treatment of CPSP.
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Biological psychiatry · Nov 2018
Positive Allosteric Modulation of Cannabinoid Receptor Type 1 Suppresses Pathological Pain Without Producing Tolerance or Dependence.
Activation of cannabinoid CB1 receptors suppresses pathological pain but also produces unwanted central side effects. We hypothesized that a positive allosteric modulator of CB1 signaling would suppress inflammatory and neuropathic pain without producing cannabimimetic effects or physical dependence. We also asked whether a CB1 positive allosteric modulator would synergize with inhibitors of endocannabinoid deactivation and/or an orthosteric cannabinoid agonist. ⋯ Positive allosteric modulation of CB1-receptor signaling shows promise as a safe and effective analgesic strategy that lacks tolerance, dependence, and abuse liability.