Abstract: Objective To study the relationships between the expression levels of interleukin-5(IL-5) and interferon gamma(IFN-γ) in spleen tissue and eosinophil of allergic rhinitis(AR) with the late-phase reaction in rats.Methods For the establishment of allergic rhinitis model,the rats were intraperitoneally immunized with ovalbumin(OVA) once the other day for 7 times,and then an intransal administration of OVA was used to induce allergic rhinitis.The stimulation for allergic rhinitis lasted for 10 days and then all animals were sacrificed at 30 min,1,2,4,6,or 8 hours after the last OVA administration.The spleen and nasal mucosa samples were collected.The expression of IL-5 and IFN-γ at various periods in the spleen tissues were detected with enzyme-linked immunosorbent assay(ELISA).Eosinophil(EOS) in nasal epithelium with hematoxylin-eosin(HE) staining was counted.Correlations between IL-5 and EOS numbers,IFN-γ and EOS numbers were analyzed.Results Compared with normal rats,EOS number of AR rats was increased significantly at every phase(all P<0.05).IL-5 expression levels were increased(382.86±196.17 pg/mL at 1 hr,456.45±149.82 pg/mL at 2 hr,286.33±106.56 pg/mL at 4 hr,and 259.50±128.74 pg/mL at 6 hr,respectively; all P<0.05.While the IFN-γ expression levels were reduced significantly(16.82±7.63 at 1 hr,28.47±13.33 at 2 hr,20.37±9.73 at 4 hr,and 21.73±10.30 at 6 hr,respectively;all P<0.05).There was a close positive correlation between IL-5 expression level and EOS number(r=0.942,P=0.000),while there was a moderate negative correlation between IFN-γ expression level and EOS number(r=-0.604,P=0.000).Conclusion A close positive correlation exsits between IL-5 expression level in spleen of AR rat and EOS number of nasal and a negative correlation exsits between IFN-γ expression level and EOS number in nasal mucosa.