Effect Of Dexmedetomidine On Neuropathic Pain Of P-JNK Expression In Dorsal Root And Spinal Cord In Rats

Objective:To observe the effects of dexmedetomidine on sciatic nerve chronic constriction injury (CCI) induced expression of neuropathic pain in rat spinal cord dorsal root ganglion p-JNK, to explore the mechanisms of dexmedetomidine analgesia, to provide experimental and theoretical basis for the clinical application of dexmedetomidine.Methods:54male SD rats, weighing180-220g, were randomly, the rats were randomly divided into:sham operation group (S group), CCI group (group C) and dexmedetomidine group (D group),18rats in each group.The rats in group S were only isolated sciatic nerve without ligation, C group and D group, model CCI, D in CCI group after operation until the day before surgery, a daily intraperitoneal injection of dexmedetomidine50ug/kg, S group and C group were injected with saline. On the preoperative Id, after3,7,14d randomly selected from each group6rats determination of mechanical pain threshold (MWT) and heat pain threshold (TWL).Determination of threshold, the rats were killed, the dorsal root ganglia lateral L4-6spinal cord injury,immunohistochemistry was used to detect the expression of p-JNK in spinal dorsal root ganglion.Results:The changes of pain threshold in each group:TWL, MWT basis of indifference. Compared with S group, C group and D group after TWL, MWT decreased significantly (P<0.05);compared with C group, D group after MWT and TWL increased (P<0.05); compared with postoperative7d, Cgroup and D group after3,14d MWT and TWL increased(P<0.05).Expression of p-JNK in dorsal root ganglion neurons:compared with S group, the upregulation of the expression of p-JNK in dorsal root ganglion and spinal cord of C group and D group after surgery (P<0.05); compared with C group, D group after p-JNK expression in dorsal root ganglia spinal cord cut (P<0.05); compared with postoperative7d, C group and D group after3,14d down regulated expression of p-JNK (P<0.05).Conclusion:In this experiment, effects of dexmedetomidine hydrochloridecan effectively reduce the CCI rat nociceptive hypersensitivity, and maintain a certain amount of time.Dorsal root ganglion p-JNK is involved in the signal transduction of neuropathic pain dexmedetomidine can inhibit the expression of p-JNK reduces chronic neuropathic pain in rats.