Navegando por Palavras-chave "opioid"

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    Effects of nociceptin/orphanin FQ in the acquisition of contextual and tone fear conditioning in rats
    (Amer Psychological Assoc, 2008-02-01) Fornari, Raquel V. [UNIFESP]; Soares, Juliana C. K. [UNIFESP]; Ferreira, Tatiana L. [UNIFESP]; Moreira, Karin M. [UNIFESP]; Oliveira, Maria G. M. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Nociceptin, or orphanin FQ (N/OFQ), the endogenous ligand of NOP receptors, is known to regulate learning and memory processes. To verify the role of N/OFQ in the acquisition of contextual (CFC) and tone fear conditioning (TFC), Wistar male rats received intracerebroventricular injections of N/OFQ (0.1-5.0 nmol) before training, and were tested 24 and 48 hr later to access the freezing response to context and tone, respectively. the intermediate doses (1.0 and 2.5 nmol) impaired the CFC test, sparing TFC. the highest dose (5.0 nmol) reduced freezing during both tests, a result that may be due to nonspecific effects. the posttraining injection of N/OFQ (1 or 5 nmol) did not interfere with CFC and TFC, suggesting a specific effect of the peptide in acquisition processes. Moreover, the impairment observed with N/OFQ (1 nmol) in CFC cannot be attributed to a state-dependent learning because it was not reversed by its pretest administration. the data support the negative role of N/OFQ in the acquisition of aversively motivated tasks, which encompass a spatial component and depend on the hippocampus.
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    Pro-epileptic effect of alfentanil in rats subjected to pilocarpine-induced chronic epilepsy
    (Elsevier B.V., 2006-05-15) Garrido Sanabria, Emilio Rafael; D'Andrea Vieira, Isabella; Fernanda Da Silveira Pereira, Maria; Coutinho Faria, Leonardo; Da Silva, Andre Cesar; Abrao Cavalheiro, Esper; Silva Fernandes, Maria Jose da; Universidade Federal de São Paulo (UNIFESP); Univ Brownsville
    Pharmacological induction of epileptiform activity is a complementary method to study the epileptogenic area in drug-resistant epileptic patients. Among the different activation methods, fentanyl derivatives (e.g. alfentanil) provide one of the most efficient tools in triggering epileptiform abnormalities in surgical candidates. in this study, we tested the pro-epileptic effect of different concentrations of alfentanil in hippocampal slices obtained from control and pilocarpine-treated chronic epileptic rats. the pro-convulsant action of alfentanil was also studied in control and pilocarpine-treated epileptic rats implanted with subdural and hippocampal electrodes for electroencephalographic recordings. in 90% of slices from control animals, application of affentanil (0.1-5 mu M) induced a significant enhancement in amplitude and number of population spikes recorded in the hippocampal CA1 region. in contrast, alfentanil produced a significant reduction in the amplitude of population spikes in slices from pilocarpine-treated epileptic rats. These changes were accompanied by a significant increase in the number of population spikes in the form of epileptiform multispike responses of epileptic slices. Naloxone (20 mu M) antagonized the effect of alfentanil in both control and epileptic slices, reducing the number of population spikes in slices from epileptic rats. in control rats, alfentanil induced epileptiform abnormalities in the hippocampal and cortical electroencephalographic recordings but only at concentrations higher than 200 [mu g/kg (e.g. 350 mu g/kg). Lower doses of affentanil (25 mu g/kg) elicited epileptiform abnormalities only in chronic epileptic rats. the potent action of a minimal dose of alfentanil in inducing epileptiform activity suggests an enhancement of the pro-convulsant action of mu-receptor opioids in chronic temporal lobe epilepsy. (c) 2006 Elsevier Inc. All rights reserved.
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    Sedação em medicina intensiva: uso de remifentanil na prática clínica
    (Associação de Medicina Intensiva Brasileira - AMIB, 2006-06-01) Leal, Patrícia Helena Da Rocha [UNIFESP]; Guimarães, Hélio Penna [UNIFESP]; Ivo, Ricardo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Instituto Dante Pazzanese de Cardiologia Divisão de Pesquisa
    BACKGROUND AND OBJECTIVES: Critically ill patients frequently need to use sedative and analgesic drugs, as part of their treatment or during several procedures. It is a challenge for all intensive care providers to determine the best drug to be used for each patient, with less collateral effects. The objective of this study is to describe the background to give the use of remifentanil in intensive care clinical practice. CONTENTS: Remifentanil is a short acting opioid agonist little used in intensive care medicine. Several studies have been published, showing that remifentanil is a safe drug to be used for the sedation and analgesia for intensive care patients, still needing more information regardless to septic shock patients. CONCLUSIONS: Because remifentanil is a relatively new drug, it is not yet part of the routine drugs used for intensive care providers, although solid evidences of its safety and efficiency for critically ill patients.