Body temperature and pituitary-adrenal responses to restraint (15 min or 4 h) stress were evaluated in nondependent and morphine-dependent rats. Male Sprague-Dawley rats were treated twice daily with increasing doses of morphine (10-100 mg/kg, s.c.) for 16 days. Transmitters were implanted in the peritoneal cavity to monitor body temperature and blood was collected for hormone assays. Acute wit...

The negative affective states of withdrawal involve the recruitment of brain and peripheral stress circuitry [e.g., noradrenergic activity, induction of the hypothalamo-pituitary-adrenocortical (HPA) axis, and the expression and activation of heat shock proteins (Hsps)]. The present study investigated the role of extracellular signal-regulated protein kinase (ERK) and β-adrenoceptor on the resp...

Long-term use of opioids for pain management results in rapid development of tolerance and dependence leading to severe withdrawal symptoms. We have previously demonstrated that endothelin-A (ETA) receptor antagonists potentiate opioid analgesia and eliminate analgesic tolerance. This study was designed to investigate the involvement of central ET mechanisms in opioid withdrawal. The effect of ...

Introduction: This study was performed to evaluate the effects of intra-nucleus accumbens shell microinjection of Larginine (NO precursor) and L-NAME (nitric oxide synthase (NOS) inhibitor) on morphine withdrawal signs in male rats. Method: Rats were anaesthetized with a combination of ketamine and xylazine, and placed in stereotaxic apparatus, and a guide cannula was inserted into nucleus accu...

Objective(s): Evaluation of the Sophora alopecuroides var. alopecuroides seed effects on morphine withdrawal syndrome in mice and determination of the alkaloid composition of the seed total extract. Materials and Methods:The effects of the seed total extract, alkaloid fraction and major compound matrine on the mice morphine withdrawal syndrome were compared to saline and methadone.Mice were ma...

The aim of this study was to investigate the effects of magnesium as a N-Methyl–D-Aspartate (NMDA) receptor Antagnist and bromocriptine as a dopamine receptor agonist on morphine dependence and withdrawal symptoms. In the present study different groups of mice were received morphine (50 mg/kg, i.p.) for four days and on fourth day 1.5 hour after the last morphine administration they received di...

The mixed agonist-antagonist analgesics buprenorphine, butorphanol, nalbuphine, pentazocine and picenadol were compared to the prototype mu and kappa agonists morphine and Mr 2033, respectively, in the following tests in rhesus monkeys: overt behavioral effects upon acute administration in drug-naive animals; discriminative stimulus properties in monkeys trained to respond to either etorphine o...

Objectives: Opioid addiction is associated with long-term adaptive changes in the brain that involve glial activation. Agmatine is an amine formed by the decarboxylation of l-arginine by the enzyme arginine decarboxylase. It binds to α2-adrenergic and imidazoline receptors, and selectively blocks N-methyl-Daspartate receptors. Agmatine treatment was reported to have various biological actions. ...

Objectives: Opioid addiction is associated with long-term adaptive changes in the brain that involve glial activation. Agmatine is an amine formed by the decarboxylation of l-arginine by the enzyme arginine decarboxylase. It binds to α2-adrenergic and imidazoline receptors, and selectively blocks N-methyl-Daspartate receptors. Agmatine treatment was reported to have various biological actions. ...