Search results for "analgesic"
showing 10 items of 365 documents
Long-lasting rewarding effects of morphine induced by drug primings.
2005
To evaluate the persistence of the rewarding effects of morphine, the acquisition, maintenance, extinction and reinstatement of a conditioned place preference (CPP) was assessed in OF1 mice. In Experiment 1, the persistence of morphine-induced CPP was evaluated weekly. Mice showed CPP after four sessions of conditioning with 5, 10, 20 and 40 mg/kg of morphine, which lasted 0, 1, 2 and 4 weeks, respectively. In Experiment 2, after four sessions of conditioning with 40 mg/kg of morphine, the effects of four schedules of extinction differing in the time interval (2, 4, 6 or 8 weeks) between sessions were evaluated. CPP was no longer evident after 8 weeks for the groups examined each 2 or 8 wee…
Insights About the Neuroplasticity State on the Effect of Intramuscular Electrical Stimulation in Pain and Disability Associated With Chronic Myofasc…
2018
Background: There is limited evidence concerning the effect of intramuscular electrical stimulation (EIMS) on the neural mechanisms of pain and disability associated with chronic Myofascial Pain Syndrome (MPS). Objectives: To provide new insights into the EIMS long-term effect on pain and disability related to chronic MPS (primary outcomes). To assess if the neuroplasticity state at baseline could predict the long-term impact of EIMS on disability due to MPS we examined the relationship between the serum brain-derived-neurotrophic-factor (BDNF) and by motor evoked potential (MEP). Also, we evaluated if the EIMS could improve the descending pain modulatory system (DPMS) and the cortical exci…
Novel Analgesic Agents Obtained by Molecular Hybridization of Orthosteric and Allosteric Ligands
2019
AbstractDespite the high incidence of acute and chronic pain in the general population, the efficacy of currently available medications is unsatisfactory. Insufficient management of pain has a profound impact on the quality of life and can have serious physical, psychological, social, and economic consequences. This unmet need reflects a failure to develop novel classes of analgesic drugs with superior clinical properties and lower risk of abuse. Nevertheless, recent advances in our understanding of the neurobiology of pain are offering new opportunities for developing different therapeutic approaches. Among those, the activation of M2 muscarinic acetylcholine receptors, which play a key ro…
The effects of morphine on the temporal structure of Wistar rat behavioral response to pain in hot-plate
2016
Rationale: The largest amount of researches on the hot-plate test was carried out using quantitative assessments. However, the evaluation of the relationships among the different elements that compose the behavioral response to pain requires different approaches. Although previous studies have provided clear information on the behavioral structure of the response, no data are available on its temporal structure. Objectives: The objective of this study was to investigate the temporal structure of the behavioral response to pain in Wistar rat tested in hot-plate and how this structure was influenced by morphine-induced analgesia. Methods: The behavior of four groups of subjects tested in hot-…
Spontaneous Cingulate High-Current Spikes Signal Normal and Pathological Pain States
2019
Prominent 7–12 Hz oscillations in frontal cortical networks in rats have been reported. However, the mechanism of generation and the physiological function of this brain rhythm have not yet been clarified. Multichannel extracellular field potentials of the ACC were recorded and analyzed using the current source density method in halothane-anesthetized rats. Spontaneous high-current spikes (HCSs) were localized in the deep part of layer II/III and upper part of layer V of the ACC. The frequency of HCSs in the ACC was 7–12 Hz, with an amplitude of 6.5 ± 0.76 mV/mm(2) and duration of 55.24 ± 2.43 ms. The power density significantly decreased (84.56 ± 6.93%, p < 0.05, t test) after pinching the…
Synthesis and pharmacological evaluation of 1-methyl-5- [substituted-4(3H)-oxo-1,2,3-benzotriazin-3-yl]-1H-pyrazole-4-acetic acid derivatives
1998
Several new 1-methyl-5-[substituted-4-oxo-1,2,3-benzotriazin-3-yl] -1H-pyrazole-4-acetic acids and their ethyl ester derivatives were prepared. The compounds were tested for analgesic and antiinflammatory activities, acute toxicity, ulcerogenic effect, and as in vitro inhibitors of 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD), since it is claimed that the inhibition of such an enzyme predicts in vivo antiinflammatory activity. Some compounds were more active than phenylbutazone in the phenylbenzoquinone and acetic acid peritonitis tests, and equiactive to the same drug in the carrageenin paw edema test. All the compounds inhibited the 3 alpha-HSD, but no correlation was observed with …
7-Nitroindazole blocks conditioned place preference but not hyperactivity induced by morphine.
2003
The effects of 7-nitroindazole (7-NI), a neural nitric oxide synthase (nNOS) inhibitor, on spontaneous locomotor activity, morphine-induced hyperactivity, acquisition of place conditioning and morphine-induced conditioned place preference (CPP) were evaluated in male mice. In experiment 1, animals treated with 7-NI (25, 50 and 100 mg/kg), morphine (40 mg/kg) or morphine (40 mg/kg) plus 7-NI (25, 50 or 100 mg/kg) were placed in an actimeter for 3 h. In experiment 2, animals treated with the same drugs and doses were conditioned following an unbiased procedure. 7-NI did not affect the spontaneous locomotor activity or hyperactivity induced by morphine. However, the moderate and high doses of …
Deep dry needling of trigger points located in the lateral pterygoid muscle: efficacy and safety of treatment for management of myofascial pain and t…
2014
Background To determine whether deep dry needling (DDN) of trigger points (TPs) in the lateral pterygoid muscle (LPM) would significantly reduce pain and improve function, compared with methocarbamol/paracetamol medication. Material and Methods Forty-eight patients with chronic myofascial pain located in the LPM were selected and randomly assigned to one of two groups (DDN test group, n=24; drug-treated control group, n=24). The test group received three applications of needling of the LPM once per week for three weeks, while control group patients were given two tablets of a methocarbamol/paracetamol combination every six hours for three weeks. Assessments were carried out pretreatment, 2 …
Shell/core differences in mu- and delta-opioid receptor modulation of dopamine efflux in nucleus accumbens
2008
The mu- and delta-opioid receptors located at the terminal level in nucleus accumbens are involved in the opiate modulation of dopamine release in this brain area. However, recent studies suggest that the effects of opioid drugs on the core subregion of nucleus accumbens may completely differ from those observed in the shell. We used in vivo microdialysis to simultaneously apply selective mu- and delta-opioid receptor agonists and to measure extracellular levels of dopamine in three subregions of the accumbens, namely shell, core, and the transition zone between them. The regional analysis of these subregions of the accumbens demonstrated that basal levels of dopamine and its metabolites we…
Efficacy of Periportal Infiltration and Intraperitoneal Instillation of Ropivacaine After Laparoscopic Surgery in Children
2009
Postoperative pain is less intense after laparoscopic than after open surgery. However, minimally invasive surgery is not a a pain-free procedure. Many trials have been done in adults using intraperitoneal and/or incisional local anesthetic, but similar studies have not yet been reported in the literature in children. Aim: The aim of this study was to evaluate the analgesic effect of periportal infiltration and intraperitoneal instillation of ropivacaine in children undergoing laparoscopic surgery. Materials and Methods: Thirty patients who underwent laparoscopic surgery were randomly allocated to one of three groups. Group A (n 10) received local infiltration of port sites with 10 mL of ro…