Effects of ambroxol on aquaporin 4 expressions in pulmonary tissues of rats with chronic obstructive pulmonary disease

Objective:To observe the effects of ambroxol on aquaporin 4(AQP4) expressions in pulmonary tissues of rats with chronic obstructive pulmonary disease(COPD).Methods:Male SD rats were randomly divided into 3 groups:control group(n=8),COPD model group(n=8) and ambroxol treatment group(n=8).COPD model was induced by cigarette smoking combined with lipopolyrsaccharide.Airway resistance and lung compliance were detected by lung function apparatus.RT-PCR and Western blot were used to exanime the mRNA and protein expression of AQP4.Results:Rats in COPD model showed significant increase in airway resistance(P= 0.007),decreased lung compliance(P=0.032) and marked decrease in mRNA and protein expressions of AQP4 in pulmonary tissues(P=0.000,P=0.000) compared with those in control group.In addition,ambroxol significantly improved pulmonary function(P=0.014,P=0.037) and increased mRNA and protein expressions of AQP4 in COPD rats(P=0.000,P=0.000).Conclusions:Ambroxol shows protective effects on pulmonary function in COPD rat model and the mechanism is related with up-regulation of AQP4 expression.