The aim of this study was to investigate the effect of ketamine and midazolam on preventing the development of morphine tolerance and dependence and withdrawal syndrome in mice. In the present study different groups of mice were received morphine (50 mg/kg, s.c.), morphine (50 mg/kg, s.c.) + ketamine (25, 50, 75 mg/kg, i.p.) , morphine (50 mg/kg , s.c.) + midazolam (0.5, 1, 2 mg/kg, i.p.) , mor...

Glial cells play a critical role in morphine tolerance, resulting from repeated administration of morphine. Both the development and the expression of tolerance are suppressed by the analgesic lamotrigine. This study investigated the relationship between the ability of lamotrigine to maintain the antinociceptive effect of morphine during tolerance development and glial cell activation in the sp...

The aim of this study was to evaluate the effect of curcumin on morphine tolerance and the corresponding cytokine/chemokine changes. Male ICR mice were made tolerant to morphine by daily subcutaneous injection for 7 days. Intraperitoneal injections of vehicle, low-dose or high-dose curcumin were administered 15 min after morphine injection, either acutely or chronically for 7 days to test the e...

objective(s): we aimed to examine association of gene expression of mor1 and glun1 at mrna level in the lumbosacral cord and midbrain with morphine tolerance in male wistar rats. materials and methods: analgesic effects of morphine administrated intraperitoneally at doses of 0.1, 1, 5 and 10 mg/kg were examined using a hot plate test in rats with and without a history of 15 days morphine (10 mg...

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...

The role of glutamate receptors within the nucleus accumbens in morphine tolerance has been postulated. Previous studies have reported that glutamate receptors exert their effects in part through the release of nitric oxide (NO). In the present study, the effect of intra-accumbal injections of L-arginine, the NO precursor and L-NAME, the NOS inhibitor on the morphine tolerance in Wistar rats (2...

the goal of this study was to evaluate the effects of quercetin and acth injection on prevention of development of morphine tolerance and dependence in mice. in this study different groups of mice received morphine (40 mg/kg, i.p.) plus quercetin (5, 10, 25 mg/kg, ip), acth (1, 2.5, 5 iu/mice, i.p.), or combination of quercetin (5 mg/kg) and acth (1 iu/mice) once a day for four days. tolerance ...

Several lines of evidence suggest that the N-methyl-D-aspartate receptor (NMDA) and nitric oxide (NO) systems are involved in morphine tolerance. Cyclooxygenase (COX) inhibitors may also play a role in morphine tolerance by interacting with both systems. In the present study, we examined the effects of the COX inhibitors N-(2-cyclohexyloxy-4-nitrophenyl) methanesulphonamide (NS-398, selective C...

Morphine is a potent analgesic, but the molecular mechanism for tolerance formation after repeated use is not fully understood. Binding immunoglobulin protein (BiP) is an endoplasmic reticulum (ER) chaperone that is central to ER function. We examined knock-in mice expressing a mutant BiP with the retrieval sequence deleted in order to elucidate physiological processes that are sensitive to BiP...

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...