Objective To observe the influence of the therapy of dredging large intestine on airway mucus hypersecretion in rat model of chronic obstructive pulmonary disease（COPD）

and discuss the effective mechanism of treating COPD based on treating large intestine from the aspect of mucus hypersecretion.Methods The rat model of COPD was established using intratracheal injection of LPS combined with cigarette smoking.All rats were randomly divided into the normal group

model group

lung group

intestine group and lung-intestine group.The normal group and model group were given normal saline solution intragastrically and other groups were treated with corresponding medicinal for 14 days.The levels and expressions of aquaporin 5-mRNA（AQP5-mRNA） and MUC5AC-mRNA were detected by applying RT-PCR and immunohistochemistry assay.Results Compared with the normal group

in the model group the level and expression of AQP5-mRNA decreased

and level and expression of MUC5AC-mRNA increased（P<0.01）.Compared with the model group

in the intestine group the level and expression of AQP5-mRNA increased

and level and expression of MUC5AC-mRNA decreased（P<0.01）.Compared with the lung group

in the lung-intestine group the level and expression of AQP5-mRNA increased

and level and expression of MUC5AC-mRNA decreased（P<0.01）.Conclusion The level and expression of MUC5AC-mRNA can be decreased and those of AQP5-mRNA can be increased

and airway mucus hypersecretion can be inhibited by the therapy of dredging large intestine

or dredging large intestine on the base of treating lung disease.It may be one effective joints of treating COPD based on treating large intestine.