Morphine and delta9-tetrahydrocannabinol (THC) produce antinociception via mu opioid and cannabinoid CB1 receptors, respectively, located in central nervous system (CNS) regions including periaqueductal gray and spinal cord. Chronic treatment with morphine or THC produces antinociceptive tolerance and cellular adaptations that include receptor desensitization. Previous studies have shown that a...

Patients with controlled background pain associated with cancer frequently also experience episodes of moderate to severe intensity breakthrough pain. Opioid pharmacotherapy, particularly with oral morphine, remains the cornerstone for the management of cancer pain. Nasal administration of opioids provides a mechanism for more rapid drug absorption and more rapid onset of pain relief compared w...

in the present study, interactive effects of d1 and d2 dopamine receptors antagonists and different periods of lithium pretreatment on morphine dependence in mice have been investigated. this study was designed to investigate whether the hypothesis that lithium and dopaminergic mechanisms via their effects on phosphoinositide pathways and calcium flux could influence morphine withdrawal respons...

background: cuminum cyminum fruit essential oil (feo) dose-dependently can attenuate the expression of morphine tolerance and dependence in morphine-dependent mice. objective: in this study, the effects of cuminum cyminum feo on acquisition and expression of morphine-induced conditioned place preference (cpp) in morphine-sensitized mice were studied. methods: repeated subcutaneous (s.c.) admini...

Downward phase of dose-response morphine converted U shape curve was chosen as a base for investigating the effects of different doses of naloxone (0.05-0.4 mg/Kg) on morphine reward/aversion properties using place preference method. First, male Wistar rats (200-220 g) were received morphine (1-7.5 mg/Kg) for place conditioning and marginal dose of morphine (5 mg/Kg) calculated by GraphPad soft...

Pruritus (itch sensation) is the most common side effect associated with spinal administration of morphine given to humans for analgesia. A variety of agents have been proposed as antipruritics with poorly understood mechanisms and they are effective with variable success. kappa-Opioid agonists possess several actions that are opposite to micro -opioid agonists. We proposed to investigate the r...