%0 Journal Article %T An Experimental Study on Spinal Cord µ-Opioid and α2-Adrenergic Receptors mRNA Expression Following Stress-Induced Hyperalgesia in Male Rats %J Iranian Journal of Medical Sciences %I Shiraz University of Medical Sciences %Z 0253-0716 %A Hormozi, Asef %A Zarifkar, Asadollah %A Rostami, Bahar %A Naghibalhossaini, Fakhraddin %D 2019 %\ 09/01/2019 %V 44 %N 5 %P 397-405 %! An Experimental Study on Spinal Cord µ-Opioid and α2-Adrenergic Receptors mRNA Expression Following Stress-Induced Hyperalgesia in Male Rats %K Stress %K Hyperalgesia %K Spinal cord %K Receptors, opioid, mu %K Adrenergic alpha-2 receptor antagonists %R 10.30476/ijms.2019.44958 %X Background: Intense stress can change pain perception and induce hyperalgesia; a phenomenon called stress-induced hyperalgesia (SIH). However, the neurobiological mechanism of this effect remains unclear. The present study aimed to investigate the effect of the spinal cord µ-opioid receptors (MOR) and α2-adrenergic receptors (α2-AR) on pain sensation in rats with SIH. Methods: Eighteen Sprague-Dawley male rats, weighing 200-250 g, were randomly divided into two groups (n=9 per group), namely the control and stress group. The stress group was evoked by random 1-hour daily foot-shock stress (0.8 mA for 10 seconds, 1 minute apart) for 3 weeks using a communication box. The tail-flick and formalin tests were performed in both groups on day 22. The real-time RT-PCR technique was used to observe MOR and α2-AR mRNA levels at the L4-L5 lumbar spinal cord. Statistical analysis was performed using the GraphPad Prism 5 software (San Diego, CA, USA). Student’s t test was applied for comparisons between the groups. P %U https://ijms.sums.ac.ir/article_44958_ac7d093315d84cab289c5a2d31643f9d.pdf