Expression level of nuclear factor-kappa,substance P and aquaporin 4 gene in the joint synovium and the change of discharge frequency of pain sensitive neuron in the ventral posteriolateral thalamic nuclens of acute gout rats / 中华风湿病学杂志

ABSTRACT

Objective To investigate the expression level of nuclear factor-kappa(NF-κB),substance P(SP)and aquaporin 4(AQP4)gene and the change of discharge frequency of pain sensitive neurons (PSN)in the ventral posteriolateral thalamic nucleus(VPL)of acute gout(AG)rats.The neuro-genic inflammation of AG was explored.Methods Forty-eight rats were randomly divided into two groupsthe control group and the AG group. According to the time interval after injection of monosodiumurate(MSU)into the the unilateral ankle joint,the AG group was subdivided into seven groups,ie.0.5 hours group,2 hours group,6 hours group,12 hours group,24 hours group,48 hours group and 72 hours group.There were 6 rats in each group.After recording of the discharge frequency of PSN in rats VPL nucleus,the expression level of NF-κB,SP and AQP4 gene in the rats joint synovium were evaluated at mRNA level by PCR in above mentioned time.Results In the 0.5 hours group,the discharge frequency of PSN in the rats VPL nueleus and the expression level of SP gene in the rats joint synovium had increased immediately after the injection of MSU(P＜0.05).In the 6 hours group,they reached the peak level(P＜0.05),and in the 12 hours group,they began to decrease gradually(P＜0.05).In the 0.5 hours group,the expression level of NF-κB and AQP4 gene increased after the injection of MSU(P＜0.05).However,their peak level presented at the 12 hours(P＜0.05),and they decreaged after 24 hours(P＜0.05).The statistical analysis of correlation had shown that there were positive correlation among the expression level of NF-κB,substance P.AQP4 gene and the change of discharge frequency of PSN in the rats VPL nucleus.Conclusion The discharge frequency of PSN in the rats VPL and the expression level of SP gene in the rats ioint synovium can be used to evaluate the Severity of pain in the AG rats.The expression level of NF-κB and SP gene can reflect the severity of neurogenic intlammation.We can know the severity of edema of the joint synovium by detecting the expression level of AQP4 gene.Pain and neurogenic inflammation play an important role in the pathogenesis of AG.Combingelectrophysiology and biochemical technique can shade light on the pathogenesis of AG from different aspects.In the meantime,it may provide a new method for developing new drugs and new approaches for clinical treatment.