Navegando por Palavras-chave "Opioid"

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    Acute and chronic exercise modulates the expression of MOR opioid receptors in the hippocampal formation of rats
    (Elsevier B.V., 2010-10-30) Rodrigues de Oliveira, Monica Silvia; Silva Fernandes, Maria Jose da [UNIFESP]; Scorza, Fulvio Alexandre [UNIFESP]; Persike, Danielle Suzete [UNIFESP]; Scorza, Carla Alessandra [UNIFESP]; Ponte, Jaqueline Botelho da; Albuquerque, Marly de; Cavalheiro, Esper Abrao [UNIFESP]; Arida, Ricardo Mario [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Univ Mogi das Cruzes NPT
    Exercise stimulates the release of beta-endorphin and other endogenous opioid peptides that are believed to be responsible for changes in mood perception of pain and also performance Although the vast majority of literature data support the role of physical exercise in increasing beta-endorphin levels indirect measures such as increased endorphin levels in peripheral blood do not reflect opioid levels in the central nervous system the purpose of the present study was to verify whether acute and chronic exercise using both voluntary and forced exercise procedures could modify the expression of mu-opioid receptors (MOR) in rat hippocampal formation Immunoblotting analysis showed significantly enhanced MOR expression in the hippocampal formation in the acute (forced and voluntary) exercise groups when compared to the control group Conversely a significant reduction of MOR expression was noted in the chronic forced and chronic voluntary exercise groups compared to the acute forced and voluntary groups respectively MOR expression was not significantly different in rats trained using both acute or chronic exercise Immunohistochemistry analysis showed a higher number of MOR-positive cells for acute forced and voluntary exercise groups in the CA1 CA3 hilus and dentate gyrus regions compared to the control group Our findings indicate that acute and chronic exercise modulates MOR expression in the hippocampal formation of rats (C) 2010 Elsevier Inc All rights reserved
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    AGH is a new hemoglobin alpha-chain fragment with antinociceptive activity
    (Elsevier B.V., 2013-10-01) Ribeiro, Natalia M.; Toniolo, Elaine F.; Castro, Leandro M. [UNIFESP]; Russo, Lilian C.; Rioli, Vanessa; Ferro, Emer S.; Dale, Camila S.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); Butantan Inst
    Limited proteolysis of certain proteins leads to the release of endogenous bioactive peptides. Hemoglobin-derived peptides such as hemorphins and hemopressins are examples of intracellular protein-derived peptides that have antinociceptive effects by modulating G-protein coupled receptors activities. in the present study, a previously characterized substrate capture assay that uses a catalytically inactive form of the thimet oligopeptidase was combined with isotopic labeling and mass spectrometry in order to identify new bioactive peptides. Indeed, we have identified the peptide AGHLDDLPGALSAL (AGH), a fragment of the hemoglobin alpha-chain, which specifically bind to the inactive thimet oligopeptidase in the substrate capture assay. Previous peptidomics studies have identified the AGH as well as many other natural peptides derived from hemoglobin alpha-chain containing this sequence, further suggesting that AGH is a natural endogenous peptide. Pharmacological assays suggest that AGH inhibits peripheral inflammatory hyperalgesic responses through indirect activation of mu opioid receptors, without having a central nervous system activity. Therefore, we have successfully used the substrate capture assay to identify a new endogenous bioactive peptide derived from hemoglobin alpha-chain. (C) 2013 Elsevier Inc. All rights reserved.
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    Effects of morphine or naloxone on cocaine-induced genital reflexes in paradoxical sleep-deprived rats
    (Elsevier B.V., 2004-11-01) Andersen, Monica Levy [UNIFESP]; Frussa-Filho, Roberto [UNIFESP]; Tufik, Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    The involvement of opioidergic neurotransmission in the modulation of genital reflexes induced by paradoxical sleep deprivation (PSD) and cocaine in rats was the aim of the present study. Morphine (0, 1, 5 and 10 mg/kg) and naloxone (0, 0.3, 3 and 30 mg/kg) were administered prior to saline or cocaine to rats that had been deprived of sleep and the incidence of penile erections (PE) and ejaculations (EJ) was measured. PSD alone induced PE in 50% and EJ in 20% of the rats, but these behaviors were not influenced by morphine or naloxone. Cocaine potentiated the incidence of genital reflexes in PSD rats to 90% (PE) and 70% (EJ). Morphine and not naloxone significantly reduced the percentage of rats displaying this response at the highest doses. Morphine also significantly reduced PE and EJ frequencies at 10 mg/kg. Furthermore, this inhibitory effect of morphine on genital reflexes was prevented by the prior injection of naloxone. Although a number of factors are involved in such a complex phenomenon as PE and EJ, our data show that activation of the opioidergic systems by the agonist morphine reduces genital reflexes-induced by cocaine in PSD males while the antagonist, naloxone, did not have any significant effect. the findings suggest that the stimulating effects of cocaine in potentiating genital reflexes in PSD rats can be unidirectionally modified by opioidergic systems. (C) 2004 Elsevier Inc. All rights reserved.
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    Estudo prospectivo randomizado da avaliação do efeito analgésico da associação de metadona com morfina para dor do câncer
    (Universidade Federal de São Paulo (UNIFESP), 2020-03-26) Duarte, Feliciano Contardo Nepomuceno [UNIFESP]; Sakata, Rioko Kimiko [UNIFESP]; Universidade Federal de São Paulo
    Background and Objectives: Opioids are the most important analgesics for cancer pain, but tolerance and hyperalgesia may occur with the use of these drugs, reducing the effect or increasing the pain intensity. N-methyl-D-aspartate (NMDA) receptor antagonists may prevent or reduce the development of tolerance and hyperalgesia. Methadone is a weak NMDA receptor antagonist and its association with other opioids could prevent these effects, improving the analgesic effect of morphine. The primary objective of this study was to determine whether the combination of low dose methadone with morphine promotes a better analgesic effect and reduces the total morphine dose used. Methods: The study was prospective, randomized. Forty-one participants with cancer pain, starting morphine use in the third step of the analgesic ladder were studied. Those in group methadone + morphine (MM) received methadone (2,5mg / 12h) with morphine and those in group morphine (M) received morphine isolated. Both groups used morphine dose as needed. There were evaluated: pain intensity before treatment and after 2 weeks, 1 month, 2 months and 3 months; total dose of morphine used and adverse effects. Results: Pain intensity was lower in the methadone group after 2 weeks (3,6 ± 3,0 versus 6,6 ± 1,8), without significant statistical difference in the other times. There was no statistically significant difference in morphine dose, but after conversion of methadone to morphine equivalent, the total morphine dose was higher in the MM group after 2 weeks (41,7 ± 9,0 versus 32,8 ± 15,1). There was no difference in adverse effects between the groups in the evaluated times. Conclusions: The combination of methadone at a dose of 2.5 mg / 12 h with morphine for cancer pain treatment promoted faster pain control, on average ± SD from 8.3 ± 1.7 to 3.6 ± 3.0, without increasing adverse effects, but with increased total opioid dose, as a result of the sum of methadone dose converted to morphine.
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    Methadone Increases and Prolongs Detomidine-Induced Arterial Hypertension in Horses, but These Effects Are Not Mediated by Increased Plasma Concentrations of Arginine Vasopressin or Serum Concentrations of Catecholamines
    (Elsevier Science Inc, 2016) Pignaton, Wangles; Luna, Stelio Pacca Loureiro; Teixeira Neto, Francisco Jose; de Oliveira, Flavia Augusta; de Castro Neto, Eduardo Ferreira [UNIFESP]; Naffah-Mazzacoratti, Maria da Graca [UNIFESP]; Gozalo-Marcilla, Miguel
    Catecholamines and arginine vasopressin (AVP) release can affect arterial blood pressure (ABP) and hemodynamic stability in standing, sedated horses. Six mature horses were included in this prospective, randomized, crossover, blinded, experimental study. All the horses were sedated with detomidine (DET) alone (0.01 mg/kg, IV) or combined with methadone (MET) (0.01 mg/kg DET and 0.2 mg/kg MET, IV). Cardiopulmonary data and blood samples were collected 30 minutes before (prebaseline and baseline) and for 120 minutes postinjection. The combination DET/MET produced a significant increase (31%) in mean ABP (MAP) 5 minutes after drug administration which lasted for 120 minutes. Detomidine alone induced only a short-term increase in MAP (15%) at 5 minutes compared with baseline. There were significant differences between groups at 5, 15, and from 60 to 120 minutes. Plasma AVP concentrations were higher in horses receiving the treatment DET from 60 to 120 minutes than those in the combination group, for the same period. There were no significant differences in norepinephrine and epinephrine serum concentrations respect to baseline and between treatments. Detomidine induces a short-term MAP increase, and this effect was prolonged and potentiated by MET association. There is no evidence of AVP, norepinephrine, and epinephrine involvement in this effect. (C) 2016 Elsevier Inc. All rights reserved.
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    Methadone Increases and Prolongs Detomidine-Induced Arterial Hypertension in Horses, but These Effects Are Not Mediated by Increased Plasma Concentrations of Arginine Vasopressin or Serum Concentrations of Catecholamines
    (Elsevier Science Inc, 2016) Pignaton, Wangles; Luna, Stelio Pacca Loureiro; Teixeira Neto, Francisco Jose; de Oliveira, Flavia Augusta; de Castro Neto, Eduardo Ferreira [UNIFESP]; Naffah-Mazzacoratti, Maria da Graca [UNIFESP]; Gozalo-Marcilla, Miguel
    Catecholamines and arginine vasopressin (AVP) release can affect arterial blood pressure (ABP) and hemodynamic stability in standing, sedated horses. Six mature horses were included in this prospective, randomized, crossover, blinded, experimental study. All the horses were sedated with detomidine (DET) alone (0.01 mg/kg, IV) or combined with methadone (MET) (0.01 mg/kg DET and 0.2 mg/kg MET, IV). Cardiopulmonary data and blood samples were collected 30 minutes before (prebaseline and baseline) and for 120 minutes postinjection. The combination DET/MET produced a significant increase (31%) in mean ABP (MAP) 5 minutes after drug administration which lasted for 120 minutes. Detomidine alone induced only a short-term increase in MAP (15%) at 5 minutes compared with baseline. There were significant differences between groups at 5, 15, and from 60 to 120 minutes. Plasma AVP concentrations were higher in horses receiving the treatment DET from 60 to 120 minutes than those in the combination group, for the same period. There were no significant differences in norepinephrine and epinephrine serum concentrations respect to baseline and between treatments. Detomidine induces a short-term MAP increase, and this effect was prolonged and potentiated by MET association. There is no evidence of AVP, norepinephrine, and epinephrine involvement in this effect. (C) 2016 Elsevier Inc. All rights reserved.
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    Morfina: aspectos biofarmacêuticos e de farmacovigilância
    (Universidade Federal de São Paulo, 2021-02-12) Cunha, Paloma Santos [UNIFESP]; Duque, Marcelo Dutra [UNIFESP]; http://lattes.cnpq.br/7085580900560038; http://lattes.cnpq.br/2205629648227494
    A morfina é conhecida por ser o fármaco de escolha para o tratamento de dor aguda moderada e severa, principalmente quando se trata da dor oncológica. Este fármaco, um análogo opioide, possui um alto poder de analgesia devido ao seu mecanismo de ação no sistema nervoso central (SNC). Por meio de uma revisão bibliográfica, o objetivo, na presente monografia, foi apresentar as características biofarmacêuticas da morfina, que são primordiais para a compreensão dos aspectos farmacocinéticos e farmacodinâmicos deste fármaco. Além disso, foram abordadas as formas de apresentação da morfina que estão disponíveis no mercado nacional atualmente, bem como as diferenças existentes entre elas. Também foi feita uma contextualização da farmacovigilância aplicada sobre a classe de medicamentos da qual a morfina faz parte, os opioides. Desta maneira, foi possível trazer informações sobre os benefícios de um fármaco tão potente como a morfina, bem como os riscos inerentes a ele, sendo o principal deles, a depressão respiratória. Sendo assim, os aspectos físico-químicos e a classificação biofarmacêutica da morfina foram discutidos de forma a atingir os objetivos acima descritos, bem como todo o processo de absorção, metabolização, distribuição e eliminação do fármaco do organismo. Foram também discutidos os eventos adversos que este fármaco pode causar, visando atender as suas indicações e contraindicações. Dessa forma, concluiu-se que atualmente a morfina ainda é muito utilizada na clínica, mesmo com o advento de novos analgésicos opioides. Por fim, inferiu-se que portarias e diretrizes normativas são essenciais para que a dispensação e prescrição desse medicamento seja feita de forma controlada e segura, visando o bem-estar do paciente e da comunidade que o cerca, por meio de sua farmacovigilância.
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    Nalmefene Reduces Reward Anticipation in Alcohol Dependence: An Experimental Functional Magnetic Resonance Imaging Study
    (Elsevier Science Inc, 2017) Quelch, Darren R.; Mick, Inge; McGonigle, John; Ramos, Anna C. [UNIFESP]; Flechais, Remy S. A.; Bolstridge, Mark; Rabiner, Eugenii; Wall, Matthew B.; Newbould, Rexford D.; Steiniger-Brach, Bjoern; van den Berg, Franz; Boyce, Malcolm; Nilausen, Dorrit Ostergaard; Sluth, Lasse Breuning; Meulien, Didier; von der Goltz, Christoph; Nutt, David; Lingford-Hughes, Anne
    BACKGROUND: Nalmefene is a mu and delta opioid receptor antagonist,. opioid receptor partial agonist that has recently been approved in Europe for treating alcohol dependence. It offers a treatment approach for alcohol-dependent individuals with "high-risk drinking levels" to reduce their alcohol consumption. However, the neurobiological mechanism underpinning its effects on alcohol consumption remains to be determined. Using a randomized, double-blind, placebo-controlled, within-subject crossover design we aimed to determine the effect of a single dose of nalmefene on striatal blood oxygen level-dependent (BOLD) signal change during anticipation of monetary reward using the monetary incentive delay task following alcohol challenge. METHODS: Twenty-two currently heavy-drinking, non-treatment-seeking alcohol-dependent males were recruited. The effect of single dose nalmefene (18 mg) on changes in a priori defined striatal region of interest BOLD signal change during reward anticipation compared with placebo was investigated using functional magnetic resonance imaging. Both conditions were performed under intravenous alcohol administration (6% vol/vol infusion to achieve a target level of 80 mg/dL). RESULTS: Datasets from 18 participants were available and showed that in the presence of the alcohol infusion, nalmefene significantly reduced the BOLD response in the striatal region of interest compared with placebo. Nalmefene did not alter brain perfusion. CONCLUSIONS: Nalmefene blunts BOLD response in the mesolimbic system during anticipation of monetary reward and an alcohol infusion. This is consistent with nalmefene's actions on opioid receptors, which modulate the mesolimbic dopaminergic system, and provides a neurobiological basis for its efficacy.
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    Restless Legs Syndrome and Pain Disorders: What's in common?
    (Springer, 2014-11-01) Goulart, Leonardo Ierardi; Delgado Rodrigues, Raimundo Nonato; Peres, Mario Fernando Prieto [UNIFESP]; Hosp Israelita Albert Einstein; Universidade de Brasília (UnB); Universidade Federal de São Paulo (UNIFESP)
    Between 10 % and 30 % of the population report chronic pain. More than half of these also have sleep complaints. From considering these data, it can be inferred there is a significant overlapping between these conditions. Restless Legs Syndrome/Willis-Ekbom Disease (RLS/WED) is characterized by complaints of an urge to move frequently associated with dysesthesias. From that perspective, these sensations can also have painful characteristics. By the same token, the presence of comorbid diseases as predicted by a higher prevalence RLS/WED, have many of them with pain as an important complaint. Pain is a multidimensional response involving several levels of expression ranging from somatosensory to emotional. the potential shared mechanisms between RLS/WED and pain may involve sleep deprivation/fragmentation effect, inducing an increase in markers of inflammation and reduction in pain thresholds. These are modulated by several different settings of neurotransmitters with a huge participation of monoaminergic dysfunctional circuits. A thorough comprehension of these mechanisms is of utmost importance for the correct approach and treatment choices.