Abstract:Objective To explore the effects and mechanisms of glycopyrronium bromide on hyperoxia-induced acute lung injury (ALI) in young rats.Methods Ten out of thirty SD young rats were randomly selected as the control group, while the rest of the rats were successfully established as hyperoxia-induced ALI models, which were further randomly divided into the ALI group and the glycopyrronium bromide group, with 10 rats in each group. The rats in the glycopyrronium bromide group were given glycopyrronium bromide at a dose of 0.8 mg/(kg·d) via inhalation, while rats in the ALI group and the control group were administered with an equal volume of normal saline. After continuous administration for 7 days, the lung wet-to-dry weight ratio (W/D) and lung index of the young rats were measured. The serum levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), reactive oxygen species (ROS) and superoxide dismutase (SOD) were detected. The pathological changes of lung tissues and the expressions of proteins associated with the Toll-like receptor 4/myeloid differentiation factor 88 (TLR4/MyD88) pathway were compared.Results Compared with the control group, the lung W/D and the lung index were increased, serum levels of IL-1β, IL-6, TNF-α and SOD were elevated, the level of ROS was decreased, and the relative protein expressions of TLR4 and MyD88 were up-regulated in the ALI group (P < 0.05). Compared with the ALI group, the lung W/D and the lung index were decreased, serum levels of IL-1β, IL-6, TNF-α and SOD were lowered, the level of ROS was increased, and the relative protein expressions of TLR4 and MyD88 were down-regulated in the glycopyrronium bromide group (P < 0.05).Conclusions Glycopyrronium bromide can improve serum inflammatory and oxidative stress indicators, and mitigate the hyperoxia-induced ALI, the mechanism of which may be related to the TLR4/MyD88 pathway.