We have previously reported that the administration of cyclo(Leu-Gly) to mice prior to morphinization blocked the development of tolerance to the analgesic effects of morphine as well as the development of some signs of physical dependence. In the present series of experiments, the effect of the same peptide treatment on changes in dopamine receptor sensitivity induced by chronic morphine treat...

  Tolerance and dependence are two main problems that have limited morphine administration as an analgesic drug and they might be as a result of changes in the number and affinity of receptors, dysfunction of adenylate cyclase, impaired coupling between activated µ receptor and K+ channels, and changes in the K+ and Ca2+ channels. There are several reports concerning the role of some of these...

Opioid drugs, such as morphine, are among the most effective analgesics available. However, their utility for the treatment of chronic pain is limited by side effects including tolerance and dependence. Morphine acts primarily through the mu-opioid receptor (MOP-R) , which is also a target of endogenous opioids. However, unlike endogenous ligands, morphine fails to promote substantial receptor ...

Diabetes is one of the most common diseases in all societies including Iran. One of its important complications is the neuropathic pain, which can be relieved by opioid drugs such as morphine. Opioid therapy is restricted due to development of tolerance and physical or mental dependence. In this study, the effect of diabetes on morphine analgesia and development of morphine tolerance and depend...

this study took an epidemiological approach toward the problem of drug addiction in tehran. the subjects were 300 addicts chosen on the basis of stratified random selection out of the population of 3627 prisoners who were all proven addicts and sentenced to imprisonment by the court in the year 1370. a descriptive survey showed that drug addiction generally, and heroin addiction specifically, i...

Previous pharmacological studies have implicated serotonergic brain systems in opiate withdrawal syndrome. Increased brain 5-HT release is associated with the development of physical dependence to morphine. Specific serotonin reuptake inhibitors, such as fluvoxamine and sertraline reduce the severity of naloxone precipitated opioid withdrawal syndrome. Other studies have shown that 5-HT system ...

glutamate has a key role in pain perception and also development of tolerance and dependence to morphine. it has been reported that clavulanic acid affects glutamatergic transmission via activation of glutamate transporter. therefore the present study was aimed to evaluate the possible antinociceptive effect of clavulanic acid and its preventive activity against development of morphine toleranc...