Acute Respiratory Distress Syndrome Induced by White Smoke Inhalation: a Potential Animal Model For Evaluating Pathological Changes and Underlying Mechanisms

Background/Aims: White smoke inhalation (WSI) is an uncommon but potentially deadly cause of acute respiratory distress syndrome (ARDS). However, no clinical treatment protocol has been established for the treatment of WSI-induced ARDS. Therefore, it is necessary to investigate the effects of WSI in ARDS and the mechanisms underlying the effects of WSI to determine a novel therapeutic target. Methods: On the basis of the duration of continued inhalation of white smoke (3 min, 5 min, and 7 min), rats were divided into three groups (WSI-3 min, WSI-5 min, and WSI-7 min). The survival rate, pathological change, and computed tomography (CT) score were evaluated to determine the modeling conditions. In the established WSI-5 min models, evaluations were performed to evaluate the following: arterial blood gas levels, lung wet/dry weight ratio, the expression of inflammatory cytokines, and the effect of NF-κB signaling pathway. Results: The survival rate of rats at 72 h post-WSI in the WSI-3 min, WSI-5 min, and WSI-7 min groups was 83.33%, 75%, and 25%, respectively. Results from evaluation of H&E staining, CT scan, arterial blood gas levels, and lung wet/dry weight ratio suggest that the pathological changes in the rat in the WSI-5 min and WSI-7 min groups are very similar to those in patients with ARDS induced by WSI. Additionally, the expression of INF-γ, TGF-β1, TNF-α, and IL-1β were increased, and the NF-κB signaling pathway was activated in the WSI-5 min group. Conclusion: The rat model of WSI-5 min can be used as a WSI-induced ALI model for further experiments. The NF-κB signaling pathway may be a potential therapeutic target for the treatment of WSI- induced ARDS.