The capacity of morphine to suppress natural and precipitated withdrawal was compared in morphine-dependent rhesus monkeys. A similar severity of withdrawal was induced by 14-hr deprivation or precipitated by naloxone, naltrexone, cyclazocine, Win 44,441 or MR 2266. Regardless of the procedure used to induce withdrawal, behavioral signs were completely suppressed by a cumulative dose of 17.5 mg...

To explore the effect of sinomenine on the nitric oxide (NO)/neural nitric oxide synthase (nNOS) system in the cerebellum and spinal cord of morphine-dependent and morphine-withdrawal Kunming mice, mice were subjected to injection of morphine with an increasing dose for 5 d, and then were treated with sinomenine (40 mg/kg, i.p.) for another 5 d. Naloxone was used to develop acute withdrawal, an...

Both the hypothalamus-pituitary-adrenal (HPA) axis and the extrahypothalamic brain stress system are key elements of the neural circuitry that regulates the negative states during abstinence from chronic drug exposure. Orexins have recently been hypothesized to modulate the extended amygdala and to contribute to the negative emotional state associated with dependence. This study examined the im...

Objective: Opiate addiction is characterized by compulsive drug use and severe withdrawal symptoms during abstinence. Heantos 4, an herbal pharmacotherapy recently approved for opiate withdrawal treatment in Vietnam, has shown anti-craving properties. The present study is the first preclinical assessment of the effects of Heantos 4 on opiate withdrawal and the rewarding properties of morphine, ...

The clinical use of morphine to reduce pain is limited because of its drug tolerance, dependence and addiction. In the present study, the tree shrews (Tupaia belangeri chinensis) developed morphine tolerance and chronic morphine dependence by morphine injections with increasing doses (5, 10, 15, 20 mg/kg body weight for 7 days). Meanwhile, the naloxone (1.25 mg/kg body weight)-induced condition...

Regional cerebral glucose utilization was studied by 2-deoxy[14C]glucose autoradiography in morphine-dependent rats and during naloxone-induced morphine withdrawal. In morphine-dependent rats, glucose utilization was increased compared with naive controls uniformly (23-54%) in hippocampus, dentate gyrus, and subiculum and reduced in frontal cortex, striatum, anterior ventral thalamus, and media...

Introduction: Our previous study has showed that chronic administration of magnesium oxide nanoparticles (MgO NP) can reduce anxiety in adult male rat. In this study the effects of MgO NP on anxiety induced by morphine withdrawal were investigated in adult male mice. Methods: Adult male NMRI mice (weighing 27 ± 3 g) divided into groups: control, receiving intraperitoneal (i.p.) injection...

The role of stress in drug addiction is well established. The negative affective states of withdrawal most probably involve recruitment of brain stress neurocircuitry [e.g., induction of hypothalamo-pituitary-adrenocortical (HPA) axis, noradrenergic activity, and corticotropin-releasing factor (CRF) activity]. The present study investigated t$he role of CRF receptor-1 subtype (CRF1R) on the res...

There is growing evidence indicating that neuronal calcium channels play an important role in the mechanism of morphine dependence. In this study, the effects of acute and chronic administration of nitrendipine on naloxone precipitated morphine withdrawal signs were investigated. Mice were rendered dependent to morphine by subcutaneous injection of morphine over a period of 5 days. In chronic s...

As long-term opioids are increasingly used for control of chronic pain, how pain affects the rewarding effect of opioids and hence risk of prescription opioid misuse and abuse remains a healthcare concern and a challenging issue in current pain management. In this study, using a rat model of morphine self-administration, we investigated the molecular mechanisms underlying the impact of pain on ...