Abstract: Objective To investigate the therapeutic and protective effect of ambroxol hydrochloride on acute lung injury caused by aspiration of gastric juice in rats. Methods SD rats were randomly divided into control group, model group (constructed by trans-cricothyroid membrane puncture with pH≈2.3 rat gastric juice, 1.5 mL/kg) and ambroxol hydrochloride intervention group (30 mg/kg). After 24 hours of modeling, the drug was administered through caudal vein once a day for 3 days. HE staining was used to detect lung tissue, lung wet to dry weight ratio (W/D) value and arterial blood gas analysis to evaluate the degree of lung injury, ELISA was used to detect IL-6, IL-10, TNF-α and C-reactive protein (CRP) levels in serum. Results Compared with the control group, the alveolar structure showed atrophy, interstitial edema, and inflammatory cell exudation. Hyaline membrane was formed and W/D value increased, pH and arterial oxygen pressure (pO₂) decreased, arterial carbon dioxide pressure (pCO₂) increased, and serum inflammatory factors (IL-6, IL-10, TNF-α and CRP) increased (P＜0.05). Compared with the model group, the intervention reduced the pathological changes of lung tissue, W/D value decreased, pH and pO₂ increased, pCO₂ decreased, serum inflammatory factors (IL-6, IL-10, TNF-α and CRP) decreased(P＜0.05). Conclusions Ambroxol hydrochloride can effectively reduce the acute lung injury in rats caused by gastric juice aspiration and has good therapeutic and protective effects.

Key words: ambroxol hydrochloride, acute lung injury, lung wet to dry weight ratio value, inflammatory factors