Objective:To investigate the effects of Huoxiang Zhengqi liquid on the expression of AQP4 in colon mucosa in rats with dampness retention syndrome (DRS). Method:Twenty four SD rats were randomly divided into 3 groups:control group

DRS group and treatment groups (DRS+Huoxiang Zhengqi liquid)

8 rats in each group.DRS was induced in all rats

except the control group

by modified environmental and fatigued method for 6 days.After DRS model was copied

control and DRS groups were orally given with normal saline(NS

20 mL·kg-1). Rats in treatment groups were orally given with Huoxiang Zhengqi liquid(20 mL·kg-1) for 8 days.Then the expression of aquaporin 4(AQP4) on colon mucosa was determined by immunohistochemistry and Real-Time PCR. Result:Rats in model groups exhibited typical DRS with sign of hyperaemia

edema

hemorrhagic spots and bleeding in the gastric mucosa compared to control. The expression of AQP4 in colon musoca significantly decreased in DRS group compared to control group(P<0.05).Conversely

exposure of DRS rats to Huoxiang Zhengqi liquid resulted in increase in expression in AQP4 in the colon mucosa(P<0.05 versus DRS group). Conclusion:Huoxiang Zhengqi liquid could have the effect of curing the DRS-induced diarrhoea

increased expression of AQP4 may play an important role.