Administration of nicotine leads to incentive and behavioral tolerance in human and animals. Ascorbic acid administration inhibits some effects of nicotine. In the present study, the effects of ascorbic acid administration on the expression and development of nicotine-induced behavioral tolerance in female Swiss-Webster mice (20-25 g) was investigated. Animals were injected with nicotine (0.5 m...

Introduction: Stress inhibits the development of tolerance to morphine analgesia via activating Hypothalamic- Pituitary-Adrenal (HPA) axis. Modified catecholamine systems have been reported following morphine tolerance development. In the current study we tried to evaluate changes in the gene expression levels for MAO-A, MAO-B, COMT and thyrosine hydroxylase (TyH) enzymes following chronic p...

It has been shown that stress and chronic pain could prevent the development of tolerance to morphine analgesia, which appears to be related to the activation of hypothalamus–pitutitary–adrenal (HPA) axis, activation of neuroendocrine systems and changes in neurochemical levels. Moreover, the involvement of nitric oxide (NO) in the development of tolerance to morphine analgesia has been implica...

It has been shown that stress and chronic pain could prevent the development of tolerance to morphine analgesia, which appears to be related to the activation of hypothalamus–pitutitary–adrenal (HPA) axis, activation of neuroendocrine systems and changes in neurochemical levels. Moreover, the involvement of nitric oxide (NO) in the development of tolerance to morphine analgesia has been implica...

mice were rendered tolerant and dependent to morphine by subcutaneous injection of morphine over a period of 5 days. the effects of acute and chronic administration of dihydropyridine calcium channel antagonist nifedipine on the development of tolerance and naloxone-precipitated morphine withdrawal signs were investigated. a single injection of nifedipine proved to be effective in inhibiting so...

Introduction: Sex differences are observed in the development of tolerance to antinociceptive effect of opioid drugs such as morphine, but the underlying mechanisms remain unclear. Critical role of glutamate in the development and maintenance of opioid tolerance has been reported by many investigators. There are also evidences about interaction between gonadal hormones and neuromodulatory sy...

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...

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...

introduction: in order to study the alterations of beta 1 and 2 integrins mrna level in rat lumbar spinal cord following the induction of chronic pain and its effect on the development of tolerance to morphine analgesia, we examined the level of expression of these genes in the presence of chronic pain, which is an inhibitor of morphine tolerance. we used induction of chronic pain alone and in ...

frost tolerance of winter wheat depends primarily on a strong vernalization requirement, delaying the transition to reproductive phase. the responses of four bread wheat cultivars (triticum aestivum l.) to low-temperatures were examined in controlled environment and field conditions. prolonged cold treatment accelerated the transition to reproductive development in winter wheats (cv. norstar an...