اثر دگزامتازون و استرس شنا بر تعديل درد در دو روش ارزيابي درد در موش سوري

Effect of Dexamethasone and Swimming Stress on Pain Modulation by Two Pain Assessment Methods in Albino Mice

Background: Previous findings have indicated that glucocorticoids may have an important role in the modulation of acute and chronic pain. The present work investigated the effect of acute stress and dexamethasone (as a glucocorticoidsʹ agonist) on acute pain by two assessment methods (Hot Plate and Tail Flick) in Albino mice. Materials and Methods: In this experiment 60 Albino mice (25-30g) were divided into 6 groups. The animals were given 2 days to adapt to the experimentʹs condition.Tail flick and Hot plate tests were used for evaluation of analgesic effect of the drug and stress. Dexamethasone( 0.5, 1 and 2 mg/kg) as an agonist of glucocorticoids and saline were injected 3 minutes before the test or before the animals received stress by swiming in cold water (18 - 22°c).The sign of pain was movement of tail in tail flick and grooming in hot plate. Results:The findings of this study indicated that the stress of cold water and Dexamethasone (0.5 and 1mg/kg) have reduced the animalsʹ responses to pain stimulants in both methods significantly (p<0.01). The effect of 2mg/kg Dexamethasone was not significant whereas the effects of stress alone were more than Dexamethasone. Conclusion: The present data showed that stress and the activation of glucocorticoidsʹ receptors reduce the acute pain. To undrestand the analgesic mechanisms of stress and glucocorticoids, further studies remain to be accomplished.