OBJECTIVE To study the effect of analgesia caused by a local anesthetic agent (Lidocaine) in morphine dependent and independent rats. METHODS We carried out this experimental study in the Neuroscience Research Center of Kerman Medical University, Iran in 2003. We evaluated 2 groups of morphine dependent and independent rats. Morphine dependency was induced orally, and formalin was used as a n...

ABSTRACTPrevious studies have shown the role of opioid receptors located in the nucleus cuneiformis (CnF) in acute pain, but not in chronic pain models. In the present study, we have determined that possible effects of these receptors at the CnF on both early and late phases of formalin test following local and systemic morphine administration. Each rat was given a subcutaneous 50-μl injection ...

Cocaine (25 mg/kg i.p.) produces analgesia in the rat within 5 min and for a duration of 90 min as determined by the formalin test or for 30 min as determined by the hot plate test. Cocaine analgesia is unaffected by doses of naloxone that are sufficient to attenuate morphine analgesia in both tests. Chlorpromazine (3 mg/kg i.p.), SCH 23390 (100 micrograms/kg i.p.; a D1 dopamine receptor antago...

Introduction: Uncoupling protein 2 (UCP2) in the inner mitochondrial membrane changes the activity of KATP channels and the cell excitability, probably by decreasing the ATP production. Given the expression of UCP2 in primary afferent neurons, and the importance of these channels in morphine-induced analgesia, genipin, an UCP2 inhibitor, may affect these processes, when administrated intratheca...

post operative pain and its control remains one of the most important issues in the field of surgery and health care system. formalin test has been used as a method for assessing pain and analgesia in rats. systemic and spinally administered clonidine, an ?2-adrenergic agonist, is proved to enhance postoperative analgesia. it has also been shown that morphine-dependent rats experience more chro...

The current study addressed two important concerns, one pertinent to the impact of PDE-5 inhibitor (tadalafil) on morphine-induced analgesia and the second relevant to its influence on morphine-induced oxidative stress in two different pain models, the the tail-flick test (representing an acute thermal phasic pain model ) and the formalin test (representing an inflammatory tonic pain model ). T...

Introduction: Uncoupling protein 2 (UCP2) in the inner mitochondrial membrane changes the activity of KATP channels and the cell excitability, probably by decreasing the ATP production. Given the expression of UCP2 in primary afferent neurons, and the importance of these channels in morphine-induced analgesia, genipin, an UCP2 inhibitor, may affect these processes, when administrated intrath...

  In this study, the effects of lead acetate on two types of pain (nociception and inflammation) induced by formalin and its interaction with the opioid system and morphine-induced analgesia were examined. Male albino mice weighing 22-27 g were used in the experiments. Morphine was administered subcutaneously 30 minutes before formalin injection. Lead acetate was intraperitoneally administered ...

introduction: the role of midbrain reticular formation, which includes the nucleus cuneiformis (ncf), as a crucial antinociceptive region in descending pain modulation has long been investigated. in this study, we tried to highlight the role of ncf in morphine-induced antinociception in formalin-induced pain model in rats. methods: a total of 201 male wistar rats weighing 260-310 g were used in...