Several studies have demonstrated that the electromagnetic fields produce analgesic activity. The aim of this study was to investigate the effects of extremely low frequency (ELF) electromagnetic fields (EMF) on morphine analgesia and tolerance in rats. In the study, 78 adult male Wistar albino rats (approximately 240 ± 12 g) were used. The application of 50 Hz magnetic field, each day the same...

Objectives: Dependence and tolerance are major restricting factors in the clinical use of opioid analgesics. In the present study, the effects of thymoquinone, the major constituent of Nigella sativa seeds, on morphine dependence and tolerance were investigated in mice. Materials and Methods: Male adult NMRI mice were made tolerant and dependent by repeated injections of morphine (50, 50, and 7...

Background: The problem of alcohol dependence, as well as the repercussion of alcohol consumption is one of the most dramatic and socially relevant problems for modern society. Aims: Studying the development of tolerance to anxiolytic, psycho stimulant and analgesic effects of ethanol upon repeated intragastric administration of ethanol in the same dose, but in various volumes. Methods: Male Wi...

δ-Opioid receptors are G-protein-coupled receptors that regulate nociceptive and emotional responses. It has been well established that distinct agonists acting at the same G-protein-coupled receptor can engage different signaling or regulatory responses. This concept, known as biased agonism, has important biological and therapeutic implications. Ligand-biased responses are well described in c...

objectives: dependence and tolerance are major restricting factors in the clinical use of opioid analgesics. in the present study, the effects of thymoquinone, the major constituent of nigella sativa seeds, on morphine dependence and tolerance were investigated in mice. materials and methods: male adult nmri mice were made tolerant and dependent by repeated injections of morphine (50, 50, and 7...

there is some evidence supporting the reduced activity of integrins following chronic administration of morphine. this reduction might play a role in morphine tolerance development. manganese binds to the extracellular domain of integrins and makes them to be activated. the effect of integrins activation using manganese on tolerance development to the analgesic effect of morphine was investigat...

Introduction: Ultra low dose (ULD) morphine induces hyperalgesia which is mediated by excitatory Gscoupled opioid receptors. This study was designed to investigate the development of tolerance to hyperalgesic effect of morphine. Also we attempt to seek possible similarity, in view of Gs proteins, between hyperalgesic effect of ULD and hyperalgesic effect after tolerance to HD. Method: Male Wist...

BACKGROUND Opiates such as morphine are the most powerful analgesics, but their protracted use is restrained by the development of tolerance to analgesic effects. Recent works suggest that tolerance to morphine might be due to its inability to promote mu opioid receptor endocytosis, and the co-injection of morphine with a mu opioid receptor internalizing agonist like [D-Ala(2),N-Me-Phe(4),Gly-o...

There is some evidence supporting the reduced activity of integrins following chronic administration of morphine. This reduction might play a role in morphine tolerance development. Manganese binds to the extracellular domain of integrins and makes them to be activated. The effect of integrins activation using manganese on tolerance development to the analgesic effect of morphine was investi...

It is proposed that the direct analgesic effect of morphine becomes attenuated over the course of successive administrations of the narcotic by a conditioned, compensatory, hyperalgesic response elicited by the administration procedure, the net result being analgesic tolerance. Using the "hot plate" analgesia assessment situation with rats, this conditioning view of tolerance is supported by se...