| Background and Aim: Allergic Rhinnitis is characterized by eosinophil-rich inflammation, There are strong evidences that CD4~+ T cells, especially of the Th2 phenotype, induce activation,migration,collection,infiltration and apoptosis of eosinophils through the secretion of an array of cytokines (e.g., IL-5, GM-CSF) both directly and indirectly. In noble studys, Tripotolide(TP) can reduce infiltration and induce apoptosis of eosinophils strongly in the airway of guinea pigs with asthma.The mechanism of TP on apoptosis of eosinophils(EOS) has been unknown, but protein phosphorylation in cell is probably a key factor.To observe the influence of TP on gene transcripts of IL-5,GM-CSF and apoptosis of EOS in Guinea pigs,and to explore the mechanism of TP on apoptosis of EOS. Method: 60 healthy guinea pigs were divided into four groups randomly(n=15).They were OVA(ovalbumin)group,TPgroup,DM(dexamethasone)group and SC(sodiumchloride)group. Mode of allergic rhinitis was established referring to Konno. OVA was applied on guinea pigs Orderly going through three phases:basic sensitization,strong sensitization and stimulation, TP,DM and SC were applied on the other groups respectively before 30 minutes in phases of strong sensitization and stimulation.10 % chloral hydrate 0.2ml/100g was injected into abdominal cavty of guinea pigs after stimulation,then these guinea pigs were killed by cutting open the heart. Nasal fluid was collected by trachea intubation and EOS was separated from it with Percoll;Soon afterly,nasal mocosa was separated from nasal cavity . EOS and nasal mocosa were fixed with 4% paraformaldehyte/0.1M PBS.ISH (In Situ Hybridization) wascarried out to determine the expression of IL-5 mRNA,GM-CSFmRNA of EOS and nasal mocosa;In Situ Cell Death Detection Kit was applied to determine the apoptosis of EOS;IH(Immunohistochemistry) was used to determine the expression of protein tyrosine kinase (PTK)of EOS and nasal mocosa.The numbers of positive cells of each sample were calculated and expressed as x ± s .Statistics were analysed by SPSS : F-test (analysis of variance) and LSD-test (the least significant difference) Resuit:1. EOS counting (x\0\x±s): SC group, 3.25±2.71;OVA group, 13.57±5.62 ; TP group, 4.48±6.21 ; DM group, 4.79±5.36. There was significant difference between SC group and OVA group(p<0.01) ; TP and DM could reduce EOS infiltration of nasal -membrane apparently(p<0.01).2. The ISH result of nasal mocosa: The positive expressing signals of IL-5 mRNA were located in the part of glands,inflammation cells,beneath membrane and the part around small blood vessel; The positive expressing signals of GM-CSFmRNA were located in the part of glands,inflammation cells,epithelials and the part around small blood vessel.3. The ISH result of EOS: The positive expressing signals of IL-5 mRNA and GM-CSFmRNA were located in somato of EOS characterized by yellow gains. There was significant difference between SC group and OVA group (p<0.01); TP and DM could reduce the expression of IL-5 mRNA,GM-CSFmRNA in EOS apparently(p<0.01) ; There was no difference between TP group and DM group in reduction the expression of IL-5 mRNA and GM-CSFmRNA (p>0.223^Pjp>0.661) .4. The apoptosis of EOS: The positive expressing signals of apoptosis were located in the part of nucleus of EOS characterized by yellow gains. The percentage of apoptotic EOS in OVA group was significantly low than those in SC group (p<0.01) ; The percentage of apoptotic EOS in TP group and DM group was significantly high than those in OVA group and SC group; There was no difference between TP group and DM group in the percentages of apoptotic EOS.5. The expression of PTK: The positive expressing signals of PTK were located in the part of glands,inflammation cells, epithelials and the part around small blood vessel of nasalmocosa,and they also express in somato of EOS characterized by yellow gains.The expression of PTK in OVA group was significantly high than those in SC group (p<0.01); TP and DM can reduce the expression of PTK in EOS apparently (p<0.01); There was no difference between TP group and DM group in the expression of PTK in EOS (p>0.557) .6.Analysis of correlation: The infiltration of EOS in OVA group was high degree positive correlation with the expressing of IL-5 mRNA and GM-CSFmRNA in EOS of nasal fluid (/= 0.746 IP 0.713, p<0. 01) .The percentage of apoptotic EOS in OVA group was high degree negative correlation with the expressing of IL-5 mRNA and GM-CSFmRNA in EOS of nasal fluid (r= -0.667 fP -0.690,p<0.01) .The percentage of apoptotic EOS in OVA group was apparent degree negative correlation with the expressing of PTK in EOS of nasal fluid (r= -0.325 ,p<0.05) . Conclusion:1. TP can suppress the symptoms of AR model applied by OVA.2. TP can reduce the infiltration and increase the apoptosis of EOS in nasal -membrane apparently.3. TP can increase the percentage of apoptotic EOS in nasal -membrane by suppressing the expression of IL-5 mRNA and GM-CSFmRNA.4. The Mechanism that TP can increase the percentage of apoptotic EOS is probably related to the action that TP can suppress the expressing of PTK in EOS of nasal fluid.5. There is no difference between TP and DM in suppressing the symptoms and the infiltration of EOS in nasal -membrane of AR model.6. TP is worthy of being studied as a promising drug in clinical therapy for AR.
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