Several studies have demonstrated that nitric oxide (NO) is involved in hyperalgesia induced by NMDA activity in Morphine tolerance and NO synthase inhibitors can attenuate hyperalgesia in morphine tolerance. In addition, one of the possible mechanisms in morphine tolerance is reduction of GABA inhibitory effect. For this reason, we used GABA agonists (muscimol and baclofen) to investigate the ...

Several studies have demonstrated that nitric oxide (NO) is involved in hyperalgesia induced by NMDA activity in Morphine tolerance and NO synthase inhibitors can attenuate hyperalgesia in morphine tolerance. In addition, one of the possible mechanisms in morphine tolerance is reduction of GABA inhibitory effect. For this reason, we used GABA agonists (muscimol and baclofen) to investigate the ...

Nerve growth factor (NGF) is a potent mediator of inflammatory hyperalgesia, in addition to roles in the development and maintenance of neurons. We provide evidence for the novel concept that microvascular endothelial cells play a critical primary role in NGF-mediated events that lead to inflammatory hyperalgesia in rat skin. We show that, surprisingly, neutrophils are not directly activated by...

The use of multiple loose ligations of the rat sciatic nerve has been proposed as a model for the study of allodynia and hyperalgesia. This pain hypersensitivity results from both an increase in the peripheral and central sensitization. The evidence indicating that the development of neuropathic thermal hyperalgesia and mechanical allodynia requires activation of spinal cord NMDA receptors. NMD...

The use of multiple loose ligations of the rat sciatic nerve has been proposed as a model for the study of allodynia and hyperalgesia. This pain hypersensitivity results from both an increase in the peripheral and central sensitization. The evidence indicating that the development of neuropathic thermal hyperalgesia and mechanical allodynia requires activation of spinal cord NMDA receptors. NMD...

We examined thermal hyperalgesia, excitability of dorsal root ganglion (DRG) neurons, and antinociceptive effects of N-methyl-d-aspartate (NMDA) receptor antagonists in rats with injury to different regions of DRG neurons. The central or peripheral branches of axons of DRG neurons were injured by partial dorsal rhizotomy (PDR) and chronic constriction injury of sciatic nerve (CCI), respectively...

BACKGROUND Several factors are believed to influence the development and experience of pain. Human clinical pain models are central tools, in the investigation of basic physiologic pain responses, and can be applied in patients as well as in healthy volunteers. Each clinical pain model investigates different aspects of the human pain response. Brief thermal sensitization induces a mild burn inj...

Introduction: Oxidative stress is an important factor in the induction of diabetes complications especially peripheral neuropathy and hyperalgesia, and it has been proven that regular aerobic exercise and vitamin E have antioxidant effects. Therefore, this study was designed to examine effects of regular aerobic exercise and vitamin E on thermal pain threshold in streptozocin-induced diabeti...

Intrathecal injection of a nitric oxide releasing compound, NOC-18, was used to define the role of nitric oxide (NO) in the spinal mechanism of neuropathic pain caused by unilateral chronic constriction injury to rat sciatic nerves. Paw withdrawal latency was used to evaluate nociception induced by thermal stimuli before surgery and afterwards at 1, 3, and 6 h, and on days 1, 2, 3, 4, 5, 8, and...

Tolerance to the analgesic effects of an opioid occurs after its chronic administration, a pharmacological phenomenon that has been associated with the development of abnormal pain sensitivity such as hyperalgesia. In the present study, we examined the role of spinal glutamate transporters (GTs) in the development of both morphine tolerance and associated thermal hyperalgesia. Chronic morphine ...