This study investigated the role of K(ATP) channels in morphine-induced antinociception and hepatic oxidative stress in acute and inflammatory pain. The K(ATP) channel modulators (K(ATP) channel opener, diazoxide 100 mg/kg, p.o, and K(ATP) channel blocker, glibenclamide, 3 mg/kg i.p.) were administered with morphine (80 mg/kg, i.p.). Antinociception was assessed by the tail-flick and formalin t...

BACKGROUND Intrathecal administration of 5-hydroxytryptamine (5-HT) is antinociceptive to noxious heat and electrical stimuli. The contributions of different receptor subtypes to the antinociceptive effects of 5-HT are controversial. The main reasons for this are the poor receptor subtype selectivity of some agonist drugs and the difficulty of restricting drug action to the spinal cord in some ...

In this study we used the chronic (formalin test) and acute (tail flick) pain models of rats for evaluation of probable analgesic and anti-inflammatory effect of Sambucus ebulus (Se) rhizome extract. Sodium salicylate (SS) was used as a positive control. A total of 300 mg/kg of SS (i.p.) had no effect on tail flick latency, while 100 and 200 mg/kg i.p. of extract increased this latency (P < 0.0...

Corydalis yanhusuo. W.T. extracts (YHS) are widely used for the treatment of pain and inflammation. There are a few studies that assessed the effects of YHS in pain assays; however, none of these studies has systematically compared its activities in the different pain animal modes namely: acute, inflammatory and chronic pain. Furthermore, little is known about the mechanism of YHS activity in t...

Recent studies have implicated the involvement of Ca2+-dependent mechanisms, in particular, calcium/calmodulin-protein kinase II in nicotine-induced antinociception using the tail-flick test. The spinal cord was suggested as a possible site of this involvement. The present study was undertaken to investigate the hypothesis that the beta2 nicotinic receptor subunit plays a central role in nicoti...

It is well established that the vanilloid receptor, VR1, is an important peripheral mediator of nociception. VR1 receptors are also located in several brain regions, yet it is uncertain whether these supraspinal VR1 receptors have any influence on the nociceptive system. To investigate a possible nociceptive role for supraspinal VR1 receptors, capsaicin (10 nmol in 0.4 microl) was microinjected...

BACKGROUND 5-HT(1A)-R-agonist repinotan was shown to counteract a morphine-induced ventilatory depression but had pronociceptive effects at small doses (0.2 μg/kg). It remained to be clarified (1) whether a moderate dose of repinotan, sufficient to stimulate spontaneous breathing, impairs antinociception if plasma concentration decreases over time, and if (2) moderate doses prevent ventilatory ...

Nerve growth factor (NGF) induces a relatively long-term hyperalgesia in rats, whereas substance P (SP) N-terminal fragments, like SP(1-7), produce a long-lasting antinociception in mice. We used various nociceptive assays to compare the effects of these compounds on pain transmission when injected intrathecally (i.t.) in mice, and to determine whether either compound affects the action of the ...

The zona incerta (ZI) is a subthalamic nucleus connected to several structures, some of them known to be involved with antinociception. The ZI itself may be involved with both antinociception and nociception. The antinociceptive effects of stimulating the ZI with glutamate using the rat tail-flick test and a rat model of incision pain were examined. The effects of intraperitoneal antagonists of...

Previous studies showed the role of basolateral amygdala (BLA) in cannabinoid-induced antinociception. Furthermore, the nucleus accumbens (NAc) plays an important role in mediating the suppression of pain in animal models. The present study extended the role of dopamine receptors within the NAc in antinociceptive effect of cannabinoid receptor agonist, WIN55,212-2, microinjected into the BLA fo...