Antinociceptive effect of MAS MT in rats
نویسندگان
چکیده
MAS MT is a myotropic decapeptide isolated from Manduca sexta. This peptide exerts stimulatory effect on insects heart-beat frequency. The present study was undertaken in order to determine a probable antinociceptive effect in rats of native synthetic decapeptide, MAS MT-I and its two analogs, heptapeptides MAS MT-II and MAS MT-III. All these peptides were applied directly into the lateral brain ventricle (icv) at three doses: 10, 25 and 50 nmol. The analgesic (antinociceptive) effect was evaluated by a tail immersion test. It was found that two doses of MAS MT-I: 25 and 50 nmol induced significant antinociceptive effect, while MAS MT-II and MAS MT-III exert a less antinociceptive effect in comparison with native MAS MT-I. Prior icv administration of naloxone, an opioid antagonist weakly blocked MAS MT-I effect. We conclude that antinociceptive effect of MAS MT-I in rats is not mediated by central opioid system.
منابع مشابه
P-108: Reproductive Toxic Effect of Carbon Tetrachloride and Therapeutic Effect of Cornus Mas Fruit Extract on Morphology and Histology of Testis in Rats
Background: Carbon tetrachloride (CCl4), an industrial solvent, is a well-established hepatotoxin. Studies demonstrated that liver is not the only target organ of CCl4 since it causes free radical generation in other tissues such as testis. It has also been reported that exposure to CCl4 induces acute and chronic reproductive toxicity. Diverse medicinal plants have been screened and assessed fo...
متن کاملLong-term Morphine-treated Rats are more Sensitive to Antinociceptive Effect of Diclofenac than the Morphine-naive rats
This study investigates the effectiveness of the antinociceptive effects of diclofenac, an NSAID, on the nociceptive behavior of morphine-treated rats on formalin test.Rats were treated with morphine-containing drinking water for twenty one days, which induced morphine dependence. The antinociceptive effects of 8, 16, and 32 mg/kg doses of diclofenac were then evaluated and compared with distil...
متن کاملLong-term Morphine-treated Rats are more Sensitive to Antinociceptive Effect of Diclofenac than the Morphine-naive rats
This study investigates the effectiveness of the antinociceptive effects of diclofenac, an NSAID, on the nociceptive behavior of morphine-treated rats on formalin test.Rats were treated with morphine-containing drinking water for twenty one days, which induced morphine dependence. The antinociceptive effects of 8, 16, and 32 mg/kg doses of diclofenac were then evaluated and compared with distil...
متن کاملAntinociceptive Effect of Morphine Microinjections into the Dorsal Hippocampus in the Formalin-Induced Orofacial Pain in Rats
In the present study, the effects of intra-hippocampal microinjections of morphine (an opioid agonist) and naloxone (an opioid antagonist) were investigated in the formalin-induced orofacial pain in rats. Orofacial pain was induced by subcutaneous injection of formalin (1 %, 50 μl) in the upper lip region and the time spent of face rubbing was measured in 3-min blocks for 45 min. Formalin induc...
متن کاملThe effect of AT2 and Mas receptors antagonists on renal hemodynamic and excretory disorders induced by ischemia/reperfusion in male and female rats
Introduction: Renal ischemia-reperfusion (RIR) may disturb renin-angiotensin system components. In this study, the effects of Mas receptor (A779) and AT2 receptor (PD123319) antagonists were examined in RIR rats. Methods: Total 60 male and female Wistar rats were assigned into 10 groups (n=6 in each group), including sham-operated group, RIR groups treated with the vehicle, A779, PD123319, ...
متن کامل