Articles: hyperalgesia.
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Neurogastroenterol. Motil. · Dec 2014
Probiotic Lactobacillus rhamnosus GG (LGG) and prebiotic prevent neonatal inflammation-induced visceral hypersensitivity in adult rats.
Increasing evidence indicates a positive effect of probiotics on the nervous system. The objective of this study was to determine if probiotic Lactobacillus rhamnosus GG (LGG) and/or prebiotics polydextrose/galactooligosaccharide (PDX/GOS) can alter the colonic sensitivity in a neonatal rat model of chronic visceral hyperalgesia and to determine whether altered sensitivity is associated with changes in neurotransmitter levels in the brain. ⋯ Results document that in rats LGG can attenuate neonatally induced chronic visceral pain measured in adulthood. Prolonged intake of LGG alters some key brain neurotransmitters and biogenic amines that could be involved in pain modulation.
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Remifentanil administration may subsequently cause paradoxical hyperalgesia in animals and humans, but mechanisms remain unclear. Manganese superoxide dismutase (MnSOD) nitration and inactivation caused by generation of reactive oxygen species and activation of N-methyl-D-aspartate (NMDA) receptors are involved in the induction and maintenance of central neuropathic pain. Hydrogen which selectively removes superoxide has gained much attention in recent years. ⋯ Ro25-6981 not 5 μg but 10 and 50 μg dosage-dependently attenuated hyperalgesia, and inhibited MnSOD nitration. Hyperalgesia and MnSOD nitration were attenuated after the combination of HRS (2.5 ml/kg) and Ro25-6981 (5 μg). In conclusion, HRS (10 ml/kg) might reverse remifentanil-induced hyperalgesia, through regulating NR2B-containing NMDAR trafficking to control MnSOD nitration and enhance MnSOD activity.
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Neuroscience letters · Nov 2014
The antiallodynic effect of intrathecal tianeptine is exerted by increased serotonin and norepinephrine in the spinal dorsal horn.
The purpose of this study was to validate the effects of tianeptine on serotonergic and noradrenergic neurotransmission in a rat model of neuropathic pain. Neuropathic pain was induced by ligating the L5 and L6 spinal nerves in male Sprague-Dawley rats, and mechanical allodynia was assessed using von Frey filaments. The effects of intrathecally administered tianeptine on mechanical allodynia were assessed. ⋯ Intrathecal tianeptine significantly increased the paw withdrawal thresholds in a dose-dependent manner and the antiallodynic effect was antagonized by dihydroergocristine and yohimbine. Microdialysis studies revealed that tianeptine increased the levels of 5-HT and NE in the spinal dorsal horn. These findings suggest that tianeptine may be effective for the management of neuropathic pain and that its analgesic mechanism is exerted by increased levels of 5-HT and NE in the synaptic cleft at the spinal level.
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Neuropathic pain is a debilitating condition caused by a lesion or disease of the somatosensory nervous system. Statins inhibit the rate-limiting step in cholesterol biosynthesis by blocking 3-hydroxy-3-methyl glutaryl coenzyme A reductase. Apart from the cholesterol-reducing actions of statins, recent studies have shown their pleiotropic actions; accordingly, their usefulness in attenuating different disease states has been described in preclinical studies. Studies in animals have also suggested their beneficial effects in attenuating neuropathic pain in various animal models of neuropathy. In these studies, their usefulness has been ascribed to cholesterol-independent actions, including anti-inflammatory, antioxidant, and neuromodulatory effects. On the contrary, clinical evidence suggests that statin administration in patients is associated with development of neuropathy, suggesting the dichotomous role of statins in neuropathic pain. The present review discusses the pain-attenuating as well as pain-inducing role of statins in preclinical and clinical studies, respectively. Furthermore, the review provides mechanistic insight to explain the paradoxical nature of this class of drugs in neuropathy in preclinical and clinical studies. ⋯ The article reviews the pain-inducing role of statins in clinical studies and its neuropathic pain-attenuating role in preclinical studies with possible mechanisms. Understanding key differences in mechanisms may help to attenuate pain induction in the clinical setting and may possibly project statins as neuropathic pain-attenuating agents.
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Eur Rev Med Pharmacol Sci · Nov 2014
Randomized Controlled TrialAcute high dose-fentanyl exposure produces hyperalgesia and tactile allodynia after coronary artery bypass surgery.
Opioid-induced hyperalgesia is well known complication of acute high dose and chronic opioid therapy. In this study, we evaluated development of opioid-induced hyperalgesia following intraoperative short-term use of µ-opioid agonist fentanyl after coronary artery bypass surgery. ⋯ Our results showed that patients undergoing coronary artery bypass surgery receiving fentanyl anesthesia developed postoperative tactile allodynia and thermal hyperalgesia and this was more prominent in high dose group.