The Involvement Of Brain-derived Neurotropic Factor (BDNF) Inflammatory Pain Through Akt Signaling Pathway Rats

Part One: Intrathecal injection of brain-derived neurotrophic factor(BDNF) si RNA could recuce inflammatory pain in ratsObjective To investigate the effect ofbrain-derived neurotropic factor(BDNF) si RNA(Small interference RNA)intrathecal injection( IT) on pain behavior in a rat model of inflammatory pain.Methods Sixty SPF grade female Sprague-Dawley(SD) rats weighing 150~180g were randomly divided intosix groups(n=12):control group, control model group;control+BDNFsi RNA group,control group+IT BDNFsi RNA;CFA group, inflammatory pain group;CFA+mismatch group, inflammatory pain+IT mismatch RNA;CFA+jet PEITM group,inflammatory pain+IT reagent jet PEITM;CFA+BDNFsi RNA group, inflammatory pain+IT BDNFsi RNA. Cultured rat microglia in vitro were decided into 3 groups:vehicle group,mismatch group and BDNFsi RNA group. Real-Time PCR and Western blot were used to investigate the effection of transfection of microglia.Rats received continuous intrathecal infusion injection of BDNF si RNA,mismatch si RNA or reagent jet PEITMat the time of 1~3 days after operation, once a day. Paw withdrawal latency to thermal stimuli(PWTL) was performed one day before and alternate day after surgery. Determination of continuous 24 h(1h、2h、3h、4h、5h、6h、12h、24h) started from the first day of injection. Another four rats from each group measured PWTL on day 3 after operation.Results Real-Time PCR shows that the expression of BDNF m RNA decreased compared with other groups.Western blot shows there is an obvious decrease of BDNF protein in BDNFsi RNA group compared with other groups.From 1 to 14 thday after operation, the PWLT threshold of CFA group,CFA+mismatch group,CFA+jet PEITM group was significantly lower than in control group.Compared with CFA group,CFA+mismatch group or CFA+jet PEITMgroup, the PWTL threshold was greatly increased in CFA+BDNFsi RNA group.Conclusion The effects of intrathecal injections BDNF si RNA in a rat model of inflammatory pain may decrease the PWTL.Part two: The involvement of brain-derivedneurotropic factor(BDNF) inflammatory pain through Akt signaling pathway ratsObjective To observe the effects andmechanism of brain-derived neurotropic factor(BDNF) and its downstream Akt signaling pathways in the inflammatory pain.Methods Sixty SPF grade female Sprague-Dawley(SD) rats weighing 150~180g were randomly divided intosix groups(n=12):control group, control model group;control+BDNFsi RNA group,control group+IT BDNFsi RNA;CFA group, inflammatory pain group;CFA+mismatch group, inflammatory pain+IT mismatch RNA;CFA+jet PEITM group,inflammatory pain+IT reagent jet PEITM;CFA+BDNFsi RNA group, inflammatory pain+IT BDNFsi RNA. Cultured rat microglia in vitro were decided into 3 groups:vehicle group,mismatch group and BDNFsi RNA group. Real-Time PCR and Western blot were used to investigate the effection of transfection of microglia. Rats received continuous intrathecal infusion injection of BDNF si RNA, mismatch si RNA or reagent jet PEITMat the time of 1~3 days after operation, once a day. Four rats from each group were sacrificed on day 3 after operation to determinate the expression level of spinal dorsal horn p-Akt(Western Blot).Results Spinal BDNF may involve in inflammatory pain through Akt signaling in rats.Conclusion...