Search results for "Narcotic"
showing 10 items of 106 documents
Therapeutic Potential of Inhibitors of Endocannabinoid Degradation for the Treatment of Stress-Related Hyperalgesia in an Animal Model of Chronic Pain
2014
The occurrence of chronic stress, depression, and anxiety can increase nociception in humans and may facilitate the transition from localized to chronic widespread pain. The mechanisms underlying chronic widespread pain are still unknown, hindering the development of effective pharmacological therapies. Here, we exposed C57BL/6J mice to chronic unpredictable stress (CUS) to investigate how persistent stress affects nociception. Next, mice were treated with multiple intramuscular nerve growth factor (NGF) injections, which induced chronic widespread nociception. Thus, combination of CUS and NGF served as a model where psychophysiological impairment coexists with long-lasting hyperalgesia. We…
Amitriptyline in neuropathic cancer pain in patients on morphine therapy: A randomized placebo-controlled, double-blind crossover study
2002
Aims and Background Amitriptyline is the most common analgesic adjuvant used in cancer patients with neuropathic pain, even though no specific studies have demonstrated a benefit. A randomized placebo-controlled, double-blind crossover study was designed to evidence the effects of amitriptyline in patients with neuropathic cancer pain. Methods Sixteen advanced cancer patients with neuropathic pain on systemic morphine therapy, no longer receiving oncologic treatment, presenting moderate pain (about 4 or more, but less than 7, on a numerical scale of 0-10) in the last week, and given a stable morphine dose in the last 2 days were admitted to the study. During the first week of study, patient…
Improved effect of the combination naltrexone/D-penicillamine in the prevention of alcohol relapse-like drinking in rats
2014
Opioid antagonists are licensed drugs for treating alcohol use disorders; nonetheless, clinical studies have evidenced their limited effectiveness. Preclinical findings indicate that opioid receptor (OR) antagonists, such as naltrexone (NTX), reduce the alcohol deprivation effect (ADE). However, a detailed analysis of published data shows the existence of a delayed increase in ethanol consumption after continuous OR blockade, a phenomenon originally called as ‘delayed ADE’. We have recently reported that D-penicillamine (DP) is able to prevent ADE through a mechanism dependent on the inactivation of acetaldehyde, the main metabolite of ethanol. Hypothetically, OR activation would be trigge…
Induction of conditioned place preference and dopamine release by salsolinol in posterior VTA of rats: involvement of μ-opioid receptors.
2011
Salsolinol (Sal), locally administered into the posterior VTA (pVTA) of rats, produces psychomotor responses and reinforcing effects, probably, through the activation of μ-opioid receptors (MORs). The neurochemical correlates of these phenomena are, however, practically unknown. In this paper, we explore the neurochemical events and the mechanisms involved in these behaviors. To do that, we test the ability of Sal, directly microinjected into the pVTA, to induce conditioned place preference (CPP) and to increase dopamine levels in the nucleus accumbens shell. Bilateral injections of 30 pmol of Sal induced a strong CPP (rats spent around 70% of the total test time), a result that could be ex…
Antinociceptive and anti-inflammatory activities of Acacia pennata wild (Mimosaceae)
2005
The butanolic fraction of dried leaves of Acacia pennata (Mimosaceae) was tested for analgesic and anti-inflammatory activities in animal models. It showed significant protective effects against chemical stimuli (acetic acid and formalin) in the mouse. It also produced a significant increase of the threshold of sensitivity to pressure-induced pain in the rats. The extract revealed an inhibitory effect in carrageenin-induced rat paw oedema in the late phase. The results suggested that a peripheral mechanism is involved in the analgesic, associated to anti-inflammatory effect (NSAIDs-like). Among the class of compounds characterized in this fraction, flavonoids may be mainly responsible for t…
The gamma(2)-MSH peptide mediates a central analgesic effect via a GABA-ergic mechanism that is independent from activation of melanocortin receptors.
2001
Using the latency for tail-flick after thermal stimulation we have assessed the effects of alpha-, gamma(1)- and gamma(2)-MSH on nociceptive threshold in the mice. Intracisternal injections of gamma(2)-MSH induced a distinct analgesia, while gamma(1)-MSH in the same doses gave only a minor analgesia. Intracisternal alpha-MSH instead gave a short-term hyperalgesia. The effect of gamma(2)-MSH was not blocked by any of the MC(4)/MC(3)receptor antagonist HS014, naloxone or by the prior intracisternal administrations of gamma(1)-MSH. However, the gamma(2)-MSH analgesic response was completely attenuated by treating animals with the GABA(A)antagonist bicuculline. The gamma(2)-MSH analgesic effect…
Determinants of interest in extended-released buprenorphine: A survey among 366 French patients treated with buprenorphine or methadone
2021
International audience; Aim: To explore the factors determining the interest in extended-release buprenorphine (XR-BUP) injections among patients receiving opioid agonist treatment (OAT) in France.Methods: 366 patients receiving OAT for opioid use disorder, recruited in 66 French centers, were interviewed from 12/2018 to 05/2019. A structured questionnaire assessed their interest in XR-BUP using a [1-10] Likert scale. 'More' vs. 'less' interested groups were defined using the median score of interest, and their characteristics were explored using adjusted odds ratios (aORs) and 95 % confidence interval (95 %CI). Independent variables were as follows: sociodemographic characteristics, OAT-re…
Environment associated with morphine and experience of aggression modulate behaviors of postdependent mice
2002
Contexts associated with drug use can acquire secondary reinforcing properties. Furthermore, context-specific withdrawal has been observed to reflect a relatively long-lasting learned response. The aim of this study was to evaluate the effect of the environment paired with morphine after 15 days of abstinence. In the first experiment, isolated male mice received saline or morphine either in their home cage or in the distinctive environment, performing two agonistic encounters in the distinctive environment during spontaneous withdrawal. Similar groups were assigned but without aggression encounters during withdrawal. In the second experiment, animals received saline or morphine as previousl…
Morphine potentiates the impairing effects of neuroleptics on two-way active conditioned avoidance response in male mice
2004
The dopaminergic and opioid systems have effects on the conditioned avoidance response (CAR), although the possible interaction between these systems on this behaviour has not been studied. The effects of morphine (12.6 mg/kg), haloperidol (0.075 mg/kg), sulpiride (20 mg/kg) and risperidone (0.1 mg/kg) alone as well as morphine combined with these dopamine (DA) antagonists on the acquisition and performance of the CAR were explored in mice. Morphine increased avoidances but this seemed secondary to a rise in activity levels. All DA antagonists impaired CAR in the acquisition phase but only haloperidol disrupted performance. The combination of morphine plus neuroleptics impaired acquisition …
Involvement of nitric oxide synthesis in sensitization to the rewarding effects of morphine
2009
Abstract Knowledge about the specific brain changes and neural plasticity processes produced by repeated exposure to a drug is essential to progress in the field of neurobiology of addiction and the development of effective medication. In the present study, the influence of nitric oxide synthesis on sensitization to the rewarding effects of morphine has been evaluated. The effects of pre-treatment of mice with saline or 20 mg/kg of morphine plus the nitric oxide synthase inhibitor 7-nitroindazole (7NI) (12.5 or 25 mg/kg) on the place conditioning induced by a low dose of morphine (2 mg/kg) were assessed. The dose of 2 mg/kg of morphine was ineffective in animals pre-treated with saline but …