Study of the effect of ambroxol hydrochloride on pulmonary substances protein-D, WBC and PaO2 in rats toxicated with paraquat

Objective To observe the effects of ambroxol hydrochloride (AH) on suffactant proteinD (SP-D) changes in rats with acute lung injury (ALI) from paraquat (PQ) poisoning in order to evaluate the therapeutic effect of AH.Methods One hundred and twenty male rats were randomly (random number) divided into three groups,namely NS (normal saline) group,PQ group,and AT (ambroxol treat) group.On the 1st,3rd,5th and 7th day after PQ poisoning,blood samples and lung tissue were taken for laboratory examination.Venous blood samples were taken to detect WBC count and percentage of PMN ; and arterial blood for measuring PaO2.The rat lung tissue morphological changes were observed with HE staining,and lung tissue surfactant protein-D (SP-D) content was determined with Western blot.Results The numbers of WBCs in AT group were lower than those in PQ group and higher than those in NS group on the 3rd,5th and 7th day (P ＜0.01).Compared with PQ group,the percentages of PMN in AT group were decreased obviously on the 3rd,5th and 7th day (P ＜0.01),but significant higher than those in NS group (P ＜0.01).The levels of PaO2 in AT group were lower than those in NS group at the same intervals (P ＜0.01).Compared with the PQ group,the levels of PaO2 in AT group were higher on the 3rd,5th and 7th day (P ＜ 0.01).The magnitude of histopathological changes of lung tissue among three groups were obviously different; the levels of SP-D in the lung tissue in AT group were higher than those in PQ group,but lower than those in NS group at the same intervals (P ＜ 0.01).Conclusions The ambroxol hydrochloride had anti-inflammatory effect owing to pulmonary aleolar epithelial type Ⅱ cells secreting synthetic SP-D protecting the rats from paraquat poisoning. Key words: Paraquat;  Acute lung injury/acute respiratory distress syndrome;  Alveolar surface active substance-D;  Ambroxol hydrochloride