Although intravenous administration of [D-penicillamine]enkephalin (DPDPE) produces significant antinociception in rodents, the duration of antinociception is short (;15 min). The present study was conducted to test the hypothesis that duration of antinociception for DPDPE is determined by both systemic and regional disposition (i.e., blood-brain translocation), and that the magnitude of antino...

Opioids inhibit glutamatergic excitatory transmission from the periphery by activating G-protein coupled opioid receptors in the central terminals of primary-afferent neurons in the spinal substantia gelatinosa, resulting in antinociception. Opioid receptor activation in the peripheral terminals of primary-afferent neurons inhibits the production of action potentials in response to nociceptive ...

Roxindole, a DA D2 receptor agonist (2-16 mg/kg) produced dose-dependent increase in percentage antinociception. The effect which was blocked by DA D2 antagonist (-)sulpiride (50 mg/kg) and 5-HT1A receptor antagonist (-) pindolol (5 mg/kg). Roxindole (4 and 8 mg/kg) reversed both naloxone (20 mg/kg)-induced hyperalgesia and reserpine (2 mg/kg)-induced hyperalgesia. This reversal was sensitive t...

background tea (camellia sinensis) has been utilised, since time immemorial, as a beverage possessing encouraging health benefits. little scientific evidence exists in literature on the effect of this plant on pain. objectives to investigate the antinociceptive activity of iranian green tea extract. materials and methods the hydroalcoholic extract was administered to male wistar rats. formalin ...

Stress induced analgesia has been shown to utilise both non-opioidergic and opioidergic mechanisms. Earlier studies indicate that opiodergic analgesics exhibit corollary changes in blood glucose level. In this study, the changes in blood glucose level by swim induced stress and the influence of exogenous glucose administration on the stress induced antinociception were studied. Stress per se (b...

objective(s) the role of elaeagnus angustifolia fruit as an analgesic agent in acute pain has been proved earlier. in this study, the effects of aqueous extracts of three parts of this fruit (pericarp, medulla and seed) on chronic pain were investigated in mice. materials and methods a partial nerve injury was made using a tight ligature around the sciatic nerve, then doses (0.5, 1, 1.5 g/kg, i...

  The paragigantocellularis (PGi) nucleus constitutes a large portion of the ventral pontomedullary reticular formation. Neurons within the PGi have been implicated in a variety of functions including cardiovascular regulation, respiratory control, pain and analgesia. Investigators have demonstrated that electrical stimulation and microinjection of L-glutamate into the PGi produce antinocicepti...

Gossypin is a bioflavonoid isolated from Hibiscus Vitifolus Linn. The antinociception activity of gossypin has been studied in comparison with the standard antinociception agent, morphine, against the experimental model of tonic continuous pain produced by formalin. Formalin (0.1ml of 1% solution) was injected under the plantar surface of right hind paw of mice and the time an animal spent in l...