OBJECTIVETo research the influence of pathogenic dampness on changes of cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interluekin-4 (IL-4), interferon-gamma (IFN-gamma), etc. in the lung of rats with different gradients of evil-cold invading Fei. Methods One hundred and four Wistar rats of SPF grade were randomized depending on the digital table into 13 groups, 8 in each group: the normal temperature group, the 6 evil-cold invasive groups (ECG1-6) and the 6 cold-dampness invasive groups (CDG1-6). Rats in the ECG and CDG groups were exposed to cold or cold-dampness to different gradients, for subgroups 1 to 6, -10 degrees C, 0 degrees C, 10 degrees C, 20-10 degrees C, 20-0 degrees C and 20 - -10 degrees C was applied respectively for 2 h, then fed at room temperature to observe their general condition. Rats were sacrificed 4 days later and their lung tissue was taken out for determination of the contents of TNF-alpha, IL-6, IFN-gamma and IL-4 in lung tissue homogenate. Results Compared with the corresponding ECG groups, the contents of TNF-alpha, IL-6 and IL-4 were higher (P < 0.05 or P < 0.01), content of IFN-gamma and IFN-gamma/IL-4 ratio were significantly lower in the CDG groups (P < 0.01).

CONCLUSIONPathogenic dampness could aggravate the injury of Fei caused by the pathogenic cold to induce the change of inflammation related cytokines to a certain extent, and the unbalance of Th1/Th2 immune response in organism could be worsened as well.