Allergic Rhinitis Animal Model Induced By Fungal Allergen And Expression Of Eotaxin Gene In Upper And Lower Respiratory Mucosa In The Guinea Pig

ObjectiveAllergic Rhintis, AR, is a kind of commonly encountered diseases of ENT department. Its also a commonly encountered disease of respiratory tract. Along with the improvement of national industrialized degree, the morbidity of AR increases gradually. The pathological mechanism mainly is type I allergic reaction involved in IgE. Flower powder, dust mite and fungal, et al are commonly allergens. In recent years, researchers have paid more attention to the function of fungal in AR and nasal sinusitis, although its function to nasal disease is still not clear. Because the clustering of eosinophil in peripheral blood and tissue is the characteristic marker of allergic disease, eosinophil should be studied in order to explore the pathogenic mechanism and pathological processing of AR. In normal condition, only a small part of eosinophil exists in blood circulation or locates in tissues. The quantity would up - regulate selectively and characteristically in special condition of disease. It indicates that there should be a molecular mechanism which could selectively regulate the producing and clustering of eosinophil in human body. Eotaxin, a kind of chemokines of eosinophil found in recent years, is a kind of chemotactic agent of eosinophil. Along with the increasing knowledge of it, Eotaxin is becoming an attractive target of treating inflammatory diseases. So to build corresponding animal models would support the further research on diseases. It's very significant to reveal pathogenic mechanism andpathologic process of AR and screen effective clinical medicine through examining expression of Eotaxin in nasal mucosa and lung tissue. Researches showed recently that allergic rhinitis (AR) related closely with bronchial asthma in the respects of epidemiology and pathophysiologic mechanism, clinical manifestation and principle of treatment, et al. The inflammatory reaction of the upper and lower respiratory tracts has a consistency and they correlate closely. So in our study, we detect expression of Eotaxin gene in nasal mucosa and in lung tissue of guinea pigs meanwhile in order to explore the function of Eotaxin gene in the upper and lower respiratory tracts and their interrelationship.Materials and MethodsBuilding animal model of AR of guinea pig led by fungal allergen. 24 guinea pigs were separated into 3 groups, group A, B, and C. group A and B were sensitized by intra - abdominal injection of fungal allergen Alternaria Alter-nata with different dose (1.0ml and 0.5ml respectively). Two weeks later, they were given allergen by nasal excitation. Group C, as control group, was given normal saline replaced of allergen. Investigated the difference of behavioristics, smear of nasal secretion and histopathology of septum mucosa.Expression of Eotaxin gene in nasal mucosa of AR of guinea induced by fungal. On the basis of building animal model of AR, examined expression of Eotaxin gene in septum mucosa of guinea pig by in situ - hybridization and investigate changes of nasal mucosa by histopathological method.Expression of Eotaxin gene in lung tissue of AR of guinea pig induced by fungal and the interrelationship with that in nasal mucosa. Built animal model of AR by applying the method of experiment 1 and examined expression of Eotaxin gene by in situ - hybridization method applied in experiment 2 in lung tissue attacked indirectly by allergen. Compared the expression with that in nasal mucosa and examined the correlation by statistics method.ResultsThe behavioristics score of group A (6.40 0.99) was obviously higher than that of group B (3.50 0.82) and group C (0.70 0.83) f 30min after the final excitation. The difference was significant ( p <0. 01). In group A, there was infiltration of massive eosinophil in nasal secretion and lamina propria while in group C eosinophil was occasionally seen. Group B was between A and C.High expression of Eotaxin gene in septum mucosa of experimental group. Location of expression, mainly under the epithelia of septum mucosa and periphery of the gland, was consistent to the location of infiltration of eosinophil. There was no positive expression in control group.There was infiltration of massive eosinophil in lung tissue of experimental group. Also high expression of Eotaxin was detected around the bronchi and under the vascular endothelia. With the statistics analysis of expression quantity in septum mucosa, they correlated significantly (r =0.452}.ConclusionsAccording to behavioristics score, smear of nasal secretion and histopato-logical examination of septum mucosa, animal model of AR with typical symptoms and histopathological changes could be built if using moderate fungal allergen. It brings lights on the further research on AR which allergen is fungal.High expression of Eotaxin gene in nasal mucosa of AR induced by fungal, which has the same location as infiltration of eosinophil, showed that it had the function of special chemotaxis to eosinophil. That would lead to tissue damage through its clustering, activation and producing active mass such as cationic protein of eosinophil and main alkaline protein, et al. It also indicated Eotaxin gene played an important role in pathological process of AR induced by fungal.High expression of Eotaxin gene in lung tissue of AR of guinea pig induced by fungal, attacked indirectly by allergen, revealed there was distinct consistency and correlation in respect of inflammatory reaction of the upper and lower re-...