The Effects Of Late Asthmatic Reaction In Rats Exposed To Different Concentrations Of Sufur Dioxide

Objective:To investigate the effects of late asthmatic reaction in rats exposed to different concentrations of sufur dioxideMethods:Wistar rats were randomly divided into 4 groups, There were 10 rats of each group. Group B was asthma animal model group which was sensitized by peritoneal injection to 100mg Ovalbumin(OVA)+100mg AL(OH)3 in 1,8,15 days. Group A was control group which challenged saline that replacing the OVA, the step is the same to the group B. Group C, D respectively challenged with OVA, the step is the same to the group B, then inhaled to a low concentration 15mg/m3) and a high concentration(30mg/m3) of sulfur dioxide 4 hours a day lasting 2 weeks. A week later, Group C,D inhaled 3% OVA+saline 30min again. After OVA were challenged, Methacholine(MCH) was taken for the bronchial provocation test(BPT) in all groups through 24 hours. Evaluate RL of each rat; the concentrations of serum interleukin-13(IL-13) and immunoglobulin E(IgE) were measured by enzyme-linked immunosorbent assay(ELISA); Detect the expression of Nuclear factor kappa B(NF-κB) and Tumor necrosis factor-a(TNF-a)in the lung tissues by immunohistochemistry; Observe the pathological changes of lung tissue.Results:①here was no airways hyperresponsiveness in the control group. The airways hyperresponsiveness were significantly different between the control group and each group(F=160.541,P<0.01). The airways hyperresponsiveness of Group C and D was significantly different with Group B(P<0.01).②The Serum IL-13 concentration was significantly different between Group B,C,D and A (F=25.707,P<0.01).And significantly different between Group B,C and D(P<0.01).③The Serum IgE concentration was significantly increased in Group B,C and D than Group A(F=28.715,P<0.01).There was no significant difference among Group C,D and B(P>0.05).④here expression of NF-κB was weakly in the cytoplasm of control group. The expression of NF-κB was significantly different between Group B,C,Dand control group (F=367.442,P<0.01), and the expressional intensity level was gradually enhanced as the concentration of inhaling sulfur dioxide (P<0.01).⑤There was hardly any expression of TNF-a positive cells in the control group, and the expression of TNF-a was significantly different between Group B,C,Dand control group (F=301.286, P<0.01), the expressional intensity level was gradually enhanced as the concentration of inhaling sulfur dioxide(P<0.01).⑥The lung pathology showed the epithelial shedding, infiltration of peribronchial inflammatory cells and fibrosis on the basement membrane gradually.Conclusion:Inhaled sufur dioxide can exacerbate the late asthmatic reaction in rats...