It has been reported that morphine tolerance does not develop in the presence of chronic pain. Therefore, this study was conducted to find out whether chronic inflammatory pain is able to eliminate or attenuate the developed tolerance to analgesic effect of morphine and also to investigate the role of lumbar spinal cord as a candidate site for this interaction. Tolerance was induced in adult ma...

introduction: the nucleus paragigantocellularis lateralis (lpgi) is involved in the descending pain modulation. the neurostreoid, 17β-estradiol found in the pgi nucleus and modulates nociception by binding to estrogen receptors and also by allosteric interaction with nmda receptors. in this study, the role of nmda receptors in the 17β-estradiol-induced pain modulation was investigated by assess...

Morinda citrifolia (Rubiaceae, Noni) is a traditional medicine with various pharmacological activities. We investigated if the MeOH-, CHCl(3)- and BuOH-soluble phase and its main active component, damnacanthal, isolated from the Noni root, have antinociceptive and anti-inflammatory actions in mice. The CHCl(3)-soluble phase (3 g/kg, per os (p.o.)) significantly reduced pain-related behavior obs...

  In this study, the effects of lead acetate on two types of pain (nociception and inflammation) induced by formalin and its interaction with the opioid system and morphine-induced analgesia were examined. Male albino mice weighing 22-27 g were used in the experiments. Morphine was administered subcutaneously 30 minutes before formalin injection. Lead acetate was intraperitoneally administered ...

Introduction: Estradiol is a neuroactive steroid, which is found in several brain areas such as locus coeruleus (LC). Estradiol modulates nociception by binding to its receptors and also by allosteric interaction with other membranebound receptors like glutamate and GABAA receptors. LC is involved in noradrenergic descending pain modulation. Methods: In order to study the effect of 17β-estra...

Previous findings have shown that saffron (Crocus sativus L.) extract and its active constituents produce antinociceptive effects in the rat models of orofacial pain. In the present study, the central H2 histaminergic and alpha-2 adrenergic receptors involvement in crocetin-induced antinociception in orofacial formalin pain in rats was evaluated.The guide cannula was implant...

Objective(s): There are many reports about the role of rostral ventromedial medulla (RVM) in modulating stress-induced analgesia (SIA). In the previous study we demonstrated that temporal inactivation of RVM by lidocaine potentiated stress-induced analgesia. In this study, we investigated the effect of permanent lesion of the RVM on SIA by using formalin test as a model of acute inflammatory pa...

objective(s):based on the previous reports, silymarin can suppress nitric oxide, prostaglandin e2 (pge2), leukotrienes, cytokines production, and neutrophils infiltration. regarding the fact that inflammation plays an important role in neuropathic and formalin-induced pain, it was assumed that silymarin could reduce pain. the present study investigates the analgesic effects of silymarin in chem...

objective(s) celecoxib acts through both cox-2-dependent and -independent pathways. according to the paradoxical effect of no on the inflammatory and nociceptive signal processing, the present study designed to evaluate the probable contribution of no in the analgesic and anti-inflammatory properties of celecoxib. materials and methods different intensities of inflammatory pain were induced by ...