Objective(s) Single injection of naloxone, a selective antagonist of morphine, prior to the drug conditioning testing was used to investigate on morphine dependence. Materials and Methods Conditioning to morphine (2.5-10 mg/kg, s.c.) was established in adult male Wistar rats (weighing 200-250 g) using an unbiased procedure. Nitric oxide agents were microinjected into the central amygdala pri...

Introduction: Calcium/calmodulin-dependent protein kinase II (CaMKII) is highly expressed in the hippocampus, which has a pivotal role in reward-related memories and morphine dependence. Methods: In the present study, morphine tolerance was induced in male Wistar rats by 7 days repeated morphine injections once daily, and then gene expression profile of α-isoform of CaMKII (CaMKIIα) in the hipp...

We have examined the effects of morphine, a mu-opioid receptor agonist, on various membrane ionic currents in rat ventricular and human atrial myocytes, using patch-clamp techniques in the whole-cell configuration. Morphine produced a concentration-dependent reduction in peak transient sodium current. When the sodium current (INa) was evoked at 5-s intervals the estimated IC50 for morphine was ...

OBJECTIVES Central nucleus of amygdala (CeA) is the most important region for morphine-induced reward, and GABAergic system plays an important role on morphine reinforcement. The influence of CeA administration of GABAB receptor agonist and antagonist on the expression and acquisition of morphine-induced incentive tolerance using conditioned place preference (CPP) paradigm was investigated in t...

The ability of two opioid agonists, [d-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (DAMGO) and morphine, to induce mu-opioid receptor (MOR) phosphorylation, desensitization, and internalization was examined in human embryonic kidney (HEK) 293 cells expressing rat MOR1 as well G protein-coupled inwardly rectifying potassium channel (GIRK) channel subunits. Both DAMGO and morphine activated GIRK cur...

introduction: although tolerance to and dependence on opioids are characterized by excessive activity of camp pathway in some brain stem nuclei, the impact of morphine dependence on activity of camp pathway in paragigantocellularis nucleus (pgi), located in the rostral ventrolateral medulla, remains unclear. therefore, the effect of adenyl cyclase activator forskolin on spontaneous firing rate ...

the mechanisms of drug dependence and rewarding properties of opiates are not exactly known and several neurotransmitters seem to be involved. it is possible that the rennin-angiotensin system could interact with the opioid system, since it has been shown that angiotensin ii(ang) and ace inhibitors have analgesic, anticonvulsant and antidepression effects and in some cases they could antagonize...

background: matricaria chamomilla (mc) contains flavonoids such as apigenine which exerts benzodiazepine-like activity, therefore it may be helpful for morphine withdrawal syndrome treatment. in this study the effects of peripheral (ip) injection of mc hydroalcoholic extract was investigated on morphine withdrawal syndrome signs in rats. material &methods;: 24male wistar rats (200-250gr) were a...

Tolerance to opioid administration represents a serious medical alert in different chronic conditions. This study compares the effects of the imidazoline compounds 1, 2, and 3 on morphine tolerance in an animal model of inflammatory pain in the rat. 1, 2, and 3 have been selected in that, although bearing a common scaffold, preferentially bind to α2-adrenoceptors, imidazoline I2 receptors, or b...