Cool Restrain Stress Induced Accumulation Of Eosinophils And Change Of Th Cytokine Expressions In Nasal Mucosa Of Allergic Rhinitis In Rat

Objective:To study the_effect of cool restrain stress on the accumulation of eosinophils and expression of Th cytokines in rat nasal mucosa of allergic rhinitis model.Methods:Fifty healthy female rats were randomly divided into 5 groups:control group, allergic rhinitis(AR) group,AR plus stress group,stress plus AR group and simultaneous stress-AR group.For cool restrain stress model,the rats were anaesthetized,then bound on a plat board,and put into water at 18℃with the level of water reaching xiphoid for 2 hours a day,lasting for 3 weeks.Allergic rhinitis model in rat were established by using a chemical mixture composed with ovalbumin(Sigma,America) 0.30mg as antigen,Aluminum hydroxide powder as adjuvant and saline 1ml.The mixture was intraperitoneally injected once a day for seven consecutive days for immunization,followed by nasal antigen challenge of 5%ovalbumin local drip(10 ul)once a day for seven consecutive days.For stress-AR model, cool restrain stress was first given at a set time(11:00am) with the method mentioned above,followed by preparation of AR model.For tissue collection and preparation,the rats were anesthetized by using 25%Urethane,then nasal mucosa from septum was obtained from rats of five groups,stained routinely by haematoxylin eosin(HE) and immunohisto chemistry respectively,to observe the distribution and expression of interleukin-2, interleukin-6 and eosinophils by using software of image analysis systems under microscope.Results:The density of eosinophiles and IL-6 in the nasal mucosa of stress-AR group was significantly higher than that in AR and control groups(P＜0.05).But no significant differences between the tow groups was found when the sequence of stimulation changed as AR firstly followd by stress(p＞0.05).The expression of IL-2 in nasal mucosa of stress-AR group was significantly reduced compared with AR and control groups(p＜0.05),but there was also no significant differences between the two gropes when the sequence of stress and AR changed too.Conclusion:The abnormal infiltration and accumulation of eosinophiles and the differences in expression of IL-2 and IL-6 which represent Thl and Th2 cytokines in rat nasal mucosa varies in different groups.The eosinophiles and IL-6 are rarely expressed in control group and moderately expressed in AR group,but significantly expressed in cool restrain groups;The IL-2 representing Th1 cytokines is reduced in ? gruop.All these results indicated that cold restrain stress might play a role in inducing rat allergic rhinitis.