Analgesic tolerance to opioids has been described in both experimental and clinical conditions and may limit the clinical utility of these drugs. We have previously shown that systemic gabapentin (GBP), a non-opioid drug, prevents and reverses tolerance to systemic morphine in the rat. In this study, we investigated the effect of intrathecal GBP on spinal morphine tolerance. Studied rats were g...

antidepressants are widely used for the treatment of various neuropathic pain conditions in humans. recent studies have demonstrated that bupropion is effective for the treatment of neuropathic pain. also antidepressants like bupropion showed anti-inflammatory properties. so in the present study, the analgesic and anti-inflammatory effects of bupropion in mice and rat were investigated. the ace...

GABAergic drugs can change analgesic effect of morphine. Wide dynamic range (WDR) neurons play an important role in pain transmission and may change behaviors in morphine tolerance. In this study WDR neuron behaviors in morphine tolerant rats and rats treated with GABA agonists, were recorded to elucidate the effect of morphine and GABA agonists on WDR behavioral changes. Rats were divided to 4...

GABAergic drugs can change analgesic effect of morphine. Wide dynamic range (WDR) neurons play an important role in pain transmission and may change behaviors in morphine tolerance. In this study WDR neuron behaviors in morphine tolerant rats and rats treated with GABA agonists, were recorded to elucidate the effect of morphine and GABA agonists on WDR behavioral changes. Rats were divided to 4...

BACKGROUND Lumbar spine surgery demands intense analgesia. Preemptive multimodal analgesia (MMA) is a novel approach to attenuate the stress response to surgical stimulus. AIMS The aim of the study was to assess the intraoperative morphine consumption in patients undergoing lumbar spine surgery. PATIENTS AND METHODS A randomized, prospective, double-blind study involving 42 patients belongi...

OBJECTIVE The levels of corticosterone and noradrenalin as the two nociception modulators modify after stress condition. The propose of current study was to investigate the effect of chrysin on formalin-induced nociceptive behaviors and serum levels of corticosterone and noradrenalin in rats. MATERIALS AND METHODS Pain was induced by applying 20 μL of 5% formalin in distilled water in the sub...

Introduction: Several researches have reported that stress is able to inhibit the development of morphine tolerance via activating of Hypothalamic-Pituitary-Adrenal (HPA) axis. In the present study we tried to examine the effect of epinephrine, the product of adrenal medulla, on the development of morphine tolerance. Methods: Analgesic tolerance was induced by intrathecal (i.t.) injection of...

Pleiotrophin (PTN) is a growth factor that exhibits neurotrophic actions and is upregulated at sites of nerve injury. Upregulation of PTN levels in injured dorsal root ganglion correlates with decreased mechanical allodynia and faster recovery from Chronic Constriction Injury of the rat sciatic nerve. Despite the evidence pointing to a role of PTN in the development of chronic pain, the role of...

Agonists acting at alpha2 adrenergic and opioid receptors have analgesic properties and act synergistically when co-administered in the spinal cord; this synergy may also contribute to the potency and efficacy of spinally administered morphine. The lack of subtype-selective pharmacological agents has previously impeded the definition of the adrenergic receptor subtype(s) mediating these effects...

Exogenous and endogenous opioids have been shown to modulate the immune system. Morphine-induced immunosuppression has been investigated extensively. However, the immune-regulating function of endogenous opioid peptides is unclear. The present study aimed to evaluate the difference in effects on cellular immune function between recombinant rat β-endorphin (β-EP; 50 µg/kg) and plant source morph...