Expression Of Nuclear Factor-κB In The Middle Ear Mucosa Of Guinea Pigs With Secretory Otitis Media And The Effect Of Pyrrolidine Dithiocarbamate On Its Expression

Objective To explore the expression of nuclear factorκB (NF-κB) in the middle ear mucosa of guinea pigs with secretory otitis media (SOM) and the role of NF-κB in the development of SOM。Method SOM were produced by injecting deactivated streptococcus pneumonia(SP) into the typmpanic cavity of guinea pigs。The expression of NF-κBp65,TNF-α,and IL-1βwas examined by means of immunohistochemistry 6h,1D,3D,7D,and 14D after injection。Result NF-κBp65 expression could be detected in the middle ear mucosa as early as 6h after injection,and reached maximum at 24h after injection。The expression pattern of TNFαandIL-1βwas similar to that of NF-κB。Conclusion NF-κB was activated in the early stage of SOM induced by deactivated SP。Moreover, NF-κB could induceTNF-αandIL-1βexpression。It indicates that NF-κB may have an important role in the pathogenesis of SOM。 Objective To study the role of nuclear factor–κB(NF-κB) in the pathogenesis of secretory otitis media (SOM), and provided reliable experiment foundation for clinical treatment。Methods 76 guinea pigs were randomly divided into 3 groups: control group(10), SOM group(22) and pyrrolidine dithiocarbamat(PDTC) group(44)。The control guinea pigs were executed after right ear was injected with 0.9% sodium chloride。SOM models were produced by injecting deactivated streptococcus pneumonia into the right tympanic cavity of guinea pigs。In PDTC treated group, guinea pigs were injected intraperitoneally with PDTC at the dosages of 50 mg/kg (PDTC1 group) or 200mg。kg-1(PDTC2 group) respectively 6 hour after deactivated streptococcus pneumonia injection。。In SOM and PDTC treated group, guinea pigs were executed at 0h ,6 h, 1d, 3d , and 5d after bacteria injection。the expressions oTNF-κB, TNF-α, and IL-1βin the tympanic membrane were examined by means of immunohistochemistry。Result In SOM group, NF-κBP65,TNF-α,IL-1βcould be detected in the middle ear mucosa as early as 6h after bacteria injection , and reached maximum at 24h。Mucosa was obviously thickened in 3d to 5d。In PDTC1 group, the expression oTNF-κBP65,TNF-α,IL-1βwere similar with that in SOM group at different time points except 24h after bacteria injection。At 24 hour after injection , the level oTNF-κBP65 was lower than that in SOM group(P<0.01)。In PDTC2 group, NF-κBP65,TNF-α,IL-1βwere similar with that in SOM group at 6h。while as the expression was lower than that in SOM group at other time points。(P<0.01)。Moreover, the level of the thickness of mucosa of middle ear was lower than that in SOM group。Conclusion the results indicates that NF-κB may play an important role in the pathogenesis of SOM。NF-κB is activated in the early stage of SOM and can promote the expression of TNF-αand IL-1β。PDTC ,a NF-κB inhibitor can inhibit the expression of inflammatory mediators and the development of SOM。NF-κB inhibitors may have a potential benefit in the treatment of SOM...