BACKGROUND Quantitative sensory testing (QST), with thermal threshold determinations, is a routine part of the comprehensive clinical workup of patients suffering from chronic pain, especially those with Complex Regional Pain Syndrome seen at our outpatient pain clinic. This is done to quantitatively assess each patient's small fiber and sensory function in a controlled manner. Most patients ha...

BACKGROUND Opioid-induced hyperalgesia can develop rapidly after opioid exposure. Neuropathic pain and opioid-induced hyperalgesia share common pathophysiologic mechanisms. Gabapentin is effective for the management of neuropathic pain and may therefore prevent opioid-induced hyperalgesia. This study tested the effectiveness of gabapentin for prevention of long-lasting hyperalgesia induced by a...

BACKGROUND Activation of NMDA receptors play an important role in the development of remifentanil-induced hyperalgesia. We hypothesized that in addition to ketamine, intrathecal MgSO4 could also relieve thermal and mechanical hyperalgesia in rats. METHODS Initially, 24 Sprague-Dawley rats were divided into control group, remifentanil group, surgical incision group and remifentanil combined wi...

RFamide-related peptide-3 (RFRP-3) and neuropeptide FF (NPFF) target two different receptor subtypes called FF1 (NPFF1R) FF2 (NPFF2R) that modulate several functions. However, the study of their respective role is severely limited by absence selective blockers. We describe here design a highly NPFF1R antagonist RF3286, which potently blocks RFRP-3-induced hyperalgesia in mice luteinizing hormon...

Previously, we demonstrated intrathecal administration of oxytocin strongly induced anti-hyperalgesia in male rats. By using an oxytocin-receptor antagonist (atosiban), the descending oxytocinergic pathway was found to regulate inflammatory hyperalgesia in our previous study using male rats. The activity of this neural pathway is elevated during hyperalgesia, but whether this effect differs in ...

Interleukin-12 (IL-12) is an inflammatory Th1-driving cytokine that has been clinically used as immune therapy and vaccine adjuvant. Recently, it was reported that patients receiving IL-12 presented hyperalgesia. In the present study, we investigated the mechanical hyperalgesic effect of IL-12 in rats using two tests: 1) paw constant pressure and 2) electronic pressure-meter. In both tests, int...

Noxious stimulation of the skin with either chemical, electrical or heat stimuli leads to the development of primary hyperalgesia at the site of injury, and to secondary hyperalgesia in normal skin surrounding the injury. Secondary hyperalgesia is inducible in most individuals and is attributed to central neuronal sensitization. Some individuals develop large areas of secondary hyperalgesia (hi...

The molecular mechanisms determining magnitude and duration of inflammatory pain are still unclear. We assessed the contribution of G protein-coupled receptor kinase (GRK)-6 to inflammatory hyperalgesia in mice. We showed that GRK6 is a critical regulator of severity and duration of cytokine-induced hyperalgesia. In GRK6⁻/⁻ mice, a significantly lower dose (100 times lower) of intraplantar inte...

introduction: pharmacological blockage of glial activity has been proved useful for treatment of neuropathic pain by lowering proinflammatory cytokines. the present study is to confirm the effect of post-injury administration of pentoxifylline on chronic constriction injury (cci)-induced neuropathic pain symptoms_ and improved the efficacy of morphine anti-nociception. methods: male wistar rats...