Objective: To explore the theory of "Fei and Dachang being interior-exteriorly related" and the pathogenesis of lung injury by observing changes of inflammatory cytokines and oxygen free radicals in ulcerative colitis (UC) rats.
Methods: Totally 50 healthy male Wistar rats were randomly divided into two groups, the normal control group and the model group, 25 rats in each group. The UC model was established by allergizing colon mucosa combined with TNBS-alcohol (50%) enema. Another 25 rats were recruited as the normal control group. At week 2 and 4 after modeling, the pathomorphological changes of the lung were observed. Furthermore, the contents of tumor necrosis factor alpha (TNF-alpha) and IL-1beta were determined by ELISA. The activities of superoxide dismutase (SOD) and malondialdehyde (MDA) were evaluated with colorimetry.
Results: Compared with the normal control group, the pathomorphology of the lung tissue in the model group appeared abnormal at week 2 and 4. Compared with the normal control group, levels of TNF-alpha, IL-1beta, and MDA in the lung tissue significantly increased in the model group (P < 0. 01) and the activities of SOD significantly decreased (P < 0.05, P < 0.01).
Conclusion: TNF-alpha, IL-1beta, SOD, and MDA might be common material bases for the large intestine involved in lung disease of UC patients, thus providing a modern scientific basis for the theory of Fei and Dachang being interior-exteriorly related.