Effect Of Intralthecal,Abdominal Or Local Injection With Lappaconitione On FOS-protein Of Spinal Cord In Incision-induced Rats

Objective To study whether or not lappaconitine given by different ways and different dose suppressed spinal sensitization in the rat incision model and to contrast the efficiencies of anesthesia.Methods Fifty-six male SD rats weighing 250-300g were randomly divided into 5 groups,each with 8 rats which received incision in the plantar of the right hindpaw. Rats of test groupⅠwere only given incision , test groupⅡabdominal injection with lappaconitione 4mg/kg at 20 min prior to the incisions, test groupⅢlocal injection with 1% lappaconitione in surgical region,test groupⅣintrathecal injection with 10ug lappaconitione at 20 min prior to the incisions, test groupⅤintrathecal injection with 20ug lappaconitione at 20 min prior to the incisions, test groupⅥintrathecal injection with 40ug lappaconitione at 20 min prior to the incisions, test groupⅦintrathecal injection with lappaconitione at 20 min after the incision. A micro-catheter was inserted into subaraehnoid space in animals of groupsⅣtoⅦ5 days before. In the behavioral study, stepping behavior was evaluated in 0-60 min after hindpaw incision total 12 timepoints. Two hours later, rats were killed and perfused, L4-S1 sections of spinal cords were dissected, sliced by freezing and processed by immunostained with a rabbit polyclonal antiserum directed against c-fos, and then the changes of FLI positive neurons in the dorsal horn were studied.Result (1)Incision-induced FLI positive neurons were mainly located in the superficial dorsal horn(laminaeⅠa ndⅡ)ipsilateral to the incision. Lappaconitine treatment markedly reduced incision-evoked nociceptive behavior and decreased the numbers of FLI positive neurons of dorsal horn(P<0.01). (2) In the intrathecal injection groups, the analgesic effect of lappaconitine preincision reduced incision-evoked nociceptive behavior and decreased the numbers of FLI positive in a dose-dependant manner . (3) In the intrathecal injection groups, the analgesic effect of the same dose lappaconitine preincision is superior to the lappaconitine postincision both in behavioral experiments and spinal Fos protein(P<0.05).(4) The analgesic effect of the local injection of lappaconitine is inferior to the other administration group both in behavioral experiment and spinal Fos protein(P<0.01).Conclusion⑴The incision-evoked nociceptive behaviors and Fos protein are suppressed by lappaconitine administration in various ways.⑵The analgesic effect of lappaconitine given by intralthecal injection before pain stimulation is better than that of other administration groups, and were in dose-dependent manner.⑶Lappaconitine also has the slight local anesthesia effect.