| Objectives1. To establish the model of allergic rhinitis (AR) in SD rat.2. To present the character of morphology in allergic rhinitis of rat.3. To determine the expression of SDF-1/CXCR4 in nasal mucosa of AR.4. To observe the effect of dexamethasone (DEX) and diprazine on the expression of SDF-1/CXCR in the allergic rhinitis.Methods: Sixty-four healthy adult rats whose weight were 250～300g were randomly divided into the blank group (C1), control group (C2), model group(M), hormone-intervention group(D1,D2),histamine receptor antagonist–intervention group(HR1, HR2).Model group had 16 rats, the others had 8 rats each. The methods of establishing the model : Group M and group D1,D2,HR1, HR2 were sensitized by injection of 1ml of physiological saline containing ovalbumin (1mg) and alum (2mg) into the four footpads . Five days later, they were boosted by subcutaneous injection of 1ml of physiological saline containing ovalbumin (0.5mg) in 10 sites on the back. Then local sensitization was performed every day by dripping the ovalbumin in physiological saline (1mg/ml, 20ul) into the bilateral nasal cavities using a micropipette from the 14th day to the establishment which was defined by the symptom score. After the establishment of model, dexamethasone (1mg/kg) and diprazine (2mg/kg)were administered to group D1,D2, HR1 and HR2 by intramuscular injection once a day, group D1, HR1 were treated for one week, group D2, HR2 were treated for two weeks respectively. While group C2 were treated with physiological saline replacing ovalbumin, the others steps were the same as group M. The group C1 remains virgin. Applying with history chemistry staining, we observed the histomorphologic character of AR. The expression and changes of SDF-1/CXCR4 in nasal mucosa in each group were investigated with immunohistochemical technique (SP method). All the data are represented as means±SEM. Statistical analysis was performed using one-way ANOVA and Repeated measures with SPSS11.5 statistical package. A probability value of less than 0.05 was considered significant.Results :(1)A large number of neutrophil and eosinophile granulocyte were present in nasal smear of group M. In nasal mucosa, EOS got increase obviously in group M, and then, decreased after DEX and DIP treatment. In group C1 and C2, epithelium mucosa was composed of ciliated columnar epithelia ,goblet cell and pavement cells etc. by hemotoxylineosin (HE) staining, and submucosa without inflammatory cell infiltrated and few vessels was compact fibrous connective tissue adjacent to the surface of cartilage. While, group M showed a significant increase of mucosa thickness, vessels and glands, epithelium secretive cells, inflammatory cells, compared to group C1 and C2. After the treatment of DEX and DIP, mucosa recovered slowly, and all of vessels expanding, glands hyperplasted and inflammatory cell infiltrated did lighten. (2)Applying with immunohistochemistry method, SDF-1 expressed in nasal cellular epithelium mucosae cells (including the cilium-side of cellular columnoepithelialis and stratified pinacocyte). Phlegmonosis cellular (mostly histoleucocyte). Cellular endoepithelial gland ; capillary cell and cellular sinusoidal endothelial that mostly present in cytoplasm.CRCR4 expresses in nasal cellular epithelium mucosae cells (including the cilium-side of cellular columnoepithelialis and stratified pinacocyte). Phlegmonosis cellular (mostly histoleucocyte). Cellular endoepithelial gland .It presents in both cytomembrane and cytoplasm,but mostly in cytomembrane. ( 3 ) Computer-assissted gray scale date showed that in group M.the expreession of SDF-1 and CXCR4 increased.compared to group C1(P<0.05).The expreession in groupD1,HR1 significantly decreased versus in group M(P<0.05).Compared to groupD1,HR1,the expression in groupD2,HR2 also decreased(P<0.05).Butthere are no difference either in groupD1,HR1 or in group D2,HR2.Conclusion: According to stimulating in nasal cavity repeatedly, we established the allergic rhinitis model in rat after the system sensibilization. Group M showed a significant increase in mucosa thickness, vessels and glands, epithelium secretive cells, inflammatory cells, including eosinophile granulocytes. Applying with immunohistochemistry method, we observed that SDF-1and CXCR4 presented at same sites. We concluded that in circumstance of allergic rhinitis, the expression change of SDF-1 and CXCR4 played an important role. The possible reason that the treatment of DEX or DIP had an effect on the proceeding of allergic rhinitis was to regulate the expression of SDF-1and CXCR4 in nasal mucosa. |
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