Effects Of Preemptive Intrathecal Tramadol On Behavior And Expression Of C-fos Protein In The Spinal Cord Of The Formalin Test Rats

BackgroundTramadol is a synthetic central analgesic for moderate to severe acute and chronic pain,their side effects than traditional opiate analgesic drug less diverse delivery methods(including oral and intramuscular injection,Intravenous and rectal administration),since 1977 in Germany since the listing in the widely used clinically. Tramadol has a dual mechanism,on the one hand,opiates,ontheother hand,can inhibit noradrenaline(NE) and 5-HT(5-HT) of the re-absorption,both of which have a synergy effect,the town Pain and the effect similar to morphine,but fewer side effects,dependency and addiction is low,a few days ago has been widely used in clinical treatment of a variety of pain.This study was used to be marked with pain model nature of animal behavior-formalin-induced pain model by intrathecal(IT) to the different doses of tramadol to observe the behavior of rats and spinal c-Fos protein expression changes,Research on rats tramadol foot injury after formalin injection effect,to explore tramadol in the spinal cord level of preemptive analgesia effect,the evaluation of different doses of tramadol analgesic effectiveness analysis of its analgesic and the effectiveness of the dose. MethodsHealthy adult male SD rats,weighing 220～280g,select the successful control of the built-in sheath 36 rats were randomly divided into six groups.Saline group (NS),that is,control group,rats in the intrathecal injection of saline(NS) 10μL, 10min left foot after subcutaneous injection NS100μL;formalin group(NF group) that the experimental group,the sheath Injected with NS10μL,10min left foot after subcutaneous injection of 5%formalin 100μL;the rest of Group 4 for the experimental group(T5F group,T10F group,T20F group,FT20 group):T5F group, T10F group with the group T20F sheath Were injected with different doses of tramadol(5μg/10μL,10μg/10μL,20μg/10μL),10min left foot after subcutaneous injection of 5%formalin 100μL;FT20 first group of rats in the left foot skin 5% formalin injection 100μL,10min after intrathecal injection of tramadol(20μg/10μL). Observed in the foot after the injection of rat behavior to every 5min for a unit,each with different levels of 5min sexual injury sustained period of time,for 60min. According to the formula for conversion into a 5-minute response time of the injury score.In each group after injection 2h foot deep anesthesia in rats,perfusion fixed, check L4-L6 spinal cord segment to do c-Fos immunohistochemistry,application Biosens Digital Imagine System V1.6 software image analysis system determined the product of c-Fos-positive The value of the IOD(integrated optical density).Results1) Rat on the left foot after the injection of formalin pain occurred after the two-phase reaction on the successful replication of the formalin-induced pain model.2.hurt in the first phase reaction score,the experimental control group and experimental group and NS group,p＜0.01,than there is a marked increase in NS Group.T5F group with the NF group score relatively injury response,p＞0.05,there was no significant difference.T10F group,T20F group,FT20 group with the NF group score relatively injury response,p＜0.05,significant difference in both.T5F group,T10F group with the group T20F response to injury score compared with 22, p＜0.05,significant difference in both.3.injured in the second phase response tired score value-added compared with 22 groups:the experimental control group and experimental group and NS group,p＜0.01, than there is a marked increase in NS Group.T5F group,T10F group,T20F group, FT20 group with the NF group score relatively injury response,p＜0.05,significant difference in both.T5F group,T10F group with the group T20F response to injury score compared with 22,p＜0.05,significant difference in both.4.T20F group FT20 with the first group phase and the second-phase response to injury compared with value-added score tired,p＜0.05,significant difference in both.5.groups of spinal dorsal horn c-fos expression of the value of the IOD Feb.2:For the experiment in the control group and experimental group and NS group,p＜0.01, than there is a marked increase in NS Group.T5F group,T10F group,T20F group, FT20 group with the NF group,p＜0.01,significant difference in both.T5F group, T10F group and T20F group,p＜0.05,significant difference in both.T20F group and FT20 group,p＜0.05,significant difference in both.Conclusions1) Pre-intrathecal tramadol effective in inhibiting the injury in rats and sexual pain side of the spinal dorsal horn c-FoS protein expression and the role of dose-related.2.Tramadol administration in advance,the better the role of anti-injury,with obvious effect of preemptive analgesia.