Extracellular signal-regulated kinase (ERK), a mitogen-activated protein kinase (MAPK), transduces a broad range of extracellular stimuli into diverse intracellular responses. It has been reported that ERK is involved in the modulation of nociceptive information and central sensitization produced by intense noxious stimuli or peripheral tissue inflammation. Our previous studies showed that the ...

The present study has been designed to investigate the effect of piracetam on morphine/ buprenorphine-induced antinociception in rats and effect of piracetam on morphine or minoxidil induced relaxation in KCl-precontracted isolated rat aortic ring preparation. Nociceptive threshold was measured by the tail flick test in rats. The cumulative dose responses of morphine or minoxidil were recorded ...

introduction:adenosine as a potent vasodilator has physiological role in regulation of regional cerebral blood flow (rcbf). metod: laser-dِoppler flowmetry technique was used to study pial vessels blood flow responses to adenosine receptors agonists and antagonist. male sprague dawley rats (250-350g) that were housed in standard conditions, were anesthetized with urethane (1.5g/kg). adenosine (g...

In the present study, we investigated the protective effect of bacoside-A the active principle isolated from the plant Bacopa monniera against oxidative damage induced by morphine in rat brain. Morphine intoxicated rats received 10-160 mg/kg b.w. of morphine hydrochloride intraperitoneally for 21 days. Bacoside-A pretreated rats were administered with bacoside-A (10 mg/kg b.w/day) orally, 2 h b...

The effect of morphine on the binding of 3H-nitrendipine was studied in rat hippocampal preparations. Treatment of slices with morphine followed by the preparation of membrane fractions revealed the presence of low affinity binding sites. The effect of morphine was antagonized by naloxone. The effect was not observed when the membrane fraction was incubated with morphine. These results suggest ...

Spinal intrathecal injections of the nonsteroidal antiinflammatory analgesics (NSAIAs) indomethacin and acetylsalicylic acid, which inhibit prostaglandin synthesis, cause dose-dependent hypoalgesia in the rat. Intrathecal injections of prostaglandin-E2 (PGE2) produce dose-dependent hyperalgesia. To determine whether this action of prostaglandins on the central nervous system is mediated through...

Abstract* Introduction: Chronic morphine exposure can cause addiction and affect synaptic plasticity, but the underlying neural mechanisms of this phenomenon remain unknown. Herein we used electrophysiologic approaches in hippocampal CA1 area to examine the effect of chronic morphine administration on short-term plasticity. Methods: Experiments were carried out on hippocampal slices taken f...

UNLABELLED Methadone is a synthetic opioid analgesic that is used as an alternate to morphine and hydromorphone for patients with severe pain. It is increasingly being used in opioid rotation schedules. Methadone has an asymmetric carbon atom resulting in 2 enantiomeric forms, the d and l isomers. The racemic mixture (dl-methadone) is the form commonly used clinically. Recent studies have revea...

objectives: crocin, a constituent of saffron and yellow gardenia, possesses anti-nociceptive effects. in the present study, we investigated the effects of intra-fourth ventricle injection of crocin in a rat model of orofacial pain. the contribution of opioid system was assessed using intra-fourth ventricle injection of naloxone, an opioid receptor antagonist. materials and methods: a guide cann...

Introduction: In order to study the alterations of beta 1 and 2 integrins mRNA level in rat lumbar spinal cord following the induction of chronic pain and its effect on the development of tolerance to morphine analgesia, we examined the level of expression of these genes in the presence of chronic pain, which is an inhibitor of morphine tolerance. We used induction of chronic pain alone and ...