the involvement of supraspinal alpha-adrenergic receptors in tonic pain was assessed in formalin-induced pain in rats. the alpha2 adrenoceptor agonist clonidine, along with yohimbine and prazosin, α2 and α1 receptor antagonists, were introduced intracerebroventrically (icv) and/or systemically in different doses. the data show that 1) clonidine exerts an alpha adrenergic analgesic effect, in ad...

Introduction: 17β-Estradiol is a neuroactive steroid and its pain modulatory role has been well studied previously. 17β-Estradiol modulates nociception by binding to its receptors and also by allosteric interaction with other membrane - bound receptors such as glutamate and GABAA receptors. Paragigantocellularis lateralis (LPGi) is also involved in pain modulation and perception, in addition...

In the present study, the effects of intra-hippocampal microinjections of morphine (an opioid agonist) and naloxone (an opioid antagonist) were investigated in the formalin-induced orofacial pain in rats. Orofacial pain was induced by subcutaneous injection of formalin (1 %, 50 μl) in the upper lip region and the time spent of face rubbing was measured in 3-min blocks for 45 min. Formalin induc...

in this study, the effects of acute and chronic lithium on nociception induced by formalin and its interactions with morphine-induced analgesia were studied in mice. formalin test was selected to study nociception. subcutaneous injection of different doses of morphine (1.5, 3 and 6 mg/kg) induced analgesia in a dose dependent manner in both phases of the formalin test. intraperitoneal administr...

Introduction: It is known that acute and chronic stress induce hormonal and neuronal changes which affecting both pain threshold and nociceptive behaviours. Orexin plays an important role in modulation of pain and stress. Considering pain modulation during stress and the role of orexin in pain and stress, orexin might be involved in pain modulation during stress.We evaluated the involvement ...

objective(s): intracerebroventricular injection of orexin-a (hypocretin-1) antagonist has been shown to inhibit stress-induced analgesia. however the locations of central sites that may mediate these effects have not been totally demonstrated. this study was performed to investigate the role of rostral ventromedial medulla (rvm) orexin receptor 1 in stress-induced analgesia (sia). materials and...

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 ...

Background.  Many mechanisms are involved in pain transmission in the spinal cord.  Therefore, combination of drugs acting on different kinds of mechanisms might be useful for analgesia.  We investigated the interaction betweenγ-aminobutyric acid （GABA）B receptor agonist, baclofen, and N-methyl-D-aspartate （NMDA） receptor antagonist, AP-5, orα-amino-3-hydroxy-5-methylisoxazole-4-propionic acid ...

BACKGROUND Intraplantar administration of complete Freund's adjuvant (CFA) and formalin are two noxious stimuli commonly used to produce sustained pain-related behaviors in rodents for research on neurobiology and treatment of pain. One clinically relevant manifestation of pain is depression of behavior and mood. This study compared effects of intraplantar CFA and formalin on depression of posi...